This is libc.info, produced by makeinfo version 6.5 from libc.texinfo. This file documents the GNU C Library. This is ‘The GNU C Library Reference Manual’, for version 2.28. Copyright © 1993–2018 Free Software Foundation, Inc. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with the Invariant Sections being “Free Software Needs Free Documentation” and “GNU Lesser General Public License”, the Front-Cover texts being “A GNU Manual”, and with the Back-Cover Texts as in (a) below. A copy of the license is included in the section entitled "GNU Free Documentation License". (a) The FSF’s Back-Cover Text is: “You have the freedom to copy and modify this GNU manual. Buying copies from the FSF supports it in developing GNU and promoting software freedom.” INFO-DIR-SECTION Software libraries START-INFO-DIR-ENTRY * Libc: (libc). C library. END-INFO-DIR-ENTRY INFO-DIR-SECTION GNU C library functions and macros START-INFO-DIR-ENTRY * ALTWERASE: (libc)Local Modes. * ARGP_ERR_UNKNOWN: (libc)Argp Parser Functions. * ARG_MAX: (libc)General Limits. * BC_BASE_MAX: (libc)Utility Limits. * BC_DIM_MAX: (libc)Utility Limits. * BC_SCALE_MAX: (libc)Utility Limits. * BC_STRING_MAX: (libc)Utility Limits. * BRKINT: (libc)Input Modes. * BUFSIZ: (libc)Controlling Buffering. * CCTS_OFLOW: (libc)Control Modes. * CHAR_BIT: (libc)Width of Type. * CHILD_MAX: (libc)General Limits. * CIGNORE: (libc)Control Modes. * CLK_TCK: (libc)Processor Time. * CLOCAL: (libc)Control Modes. * CLOCKS_PER_SEC: (libc)CPU Time. * COLL_WEIGHTS_MAX: (libc)Utility Limits. * CPU_CLR: (libc)CPU Affinity. * CPU_ISSET: (libc)CPU Affinity. * CPU_SET: (libc)CPU Affinity. * CPU_SETSIZE: (libc)CPU Affinity. * CPU_ZERO: (libc)CPU Affinity. * CREAD: (libc)Control Modes. * CRTS_IFLOW: (libc)Control Modes. * CS5: (libc)Control Modes. * CS6: (libc)Control Modes. * CS7: (libc)Control Modes. * CS8: (libc)Control Modes. * CSIZE: (libc)Control Modes. * CSTOPB: (libc)Control Modes. * DTTOIF: (libc)Directory Entries. * E2BIG: (libc)Error Codes. * EACCES: (libc)Error Codes. * EADDRINUSE: (libc)Error Codes. * EADDRNOTAVAIL: (libc)Error Codes. * EADV: (libc)Error Codes. * EAFNOSUPPORT: (libc)Error Codes. * EAGAIN: (libc)Error Codes. * EALREADY: (libc)Error Codes. * EAUTH: (libc)Error Codes. * EBACKGROUND: (libc)Error Codes. * EBADE: (libc)Error Codes. * EBADF: (libc)Error Codes. * EBADFD: (libc)Error Codes. * EBADMSG: (libc)Error Codes. * EBADR: (libc)Error Codes. * EBADRPC: (libc)Error Codes. * EBADRQC: (libc)Error Codes. * EBADSLT: (libc)Error Codes. * EBFONT: (libc)Error Codes. * EBUSY: (libc)Error Codes. * ECANCELED: (libc)Error Codes. * ECHILD: (libc)Error Codes. * ECHO: (libc)Local Modes. * ECHOCTL: (libc)Local Modes. * ECHOE: (libc)Local Modes. * ECHOK: (libc)Local Modes. * ECHOKE: (libc)Local Modes. * ECHONL: (libc)Local Modes. * ECHOPRT: (libc)Local Modes. * ECHRNG: (libc)Error Codes. * ECOMM: (libc)Error Codes. * ECONNABORTED: (libc)Error Codes. * ECONNREFUSED: (libc)Error Codes. * ECONNRESET: (libc)Error Codes. * ED: (libc)Error Codes. * EDEADLK: (libc)Error Codes. * EDEADLOCK: (libc)Error Codes. * EDESTADDRREQ: (libc)Error Codes. * EDIED: (libc)Error Codes. * EDOM: (libc)Error Codes. * EDOTDOT: (libc)Error Codes. * EDQUOT: (libc)Error Codes. * EEXIST: (libc)Error Codes. * EFAULT: (libc)Error Codes. * EFBIG: (libc)Error Codes. * EFTYPE: (libc)Error Codes. * EGRATUITOUS: (libc)Error Codes. * EGREGIOUS: (libc)Error Codes. * EHOSTDOWN: (libc)Error Codes. * EHOSTUNREACH: (libc)Error Codes. * EHWPOISON: (libc)Error Codes. * EIDRM: (libc)Error Codes. * EIEIO: (libc)Error Codes. * EILSEQ: (libc)Error Codes. * EINPROGRESS: (libc)Error Codes. * EINTR: (libc)Error Codes. * EINVAL: (libc)Error Codes. * EIO: (libc)Error Codes. * EISCONN: (libc)Error Codes. * EISDIR: (libc)Error Codes. * EISNAM: (libc)Error Codes. * EKEYEXPIRED: (libc)Error Codes. * EKEYREJECTED: (libc)Error Codes. * EKEYREVOKED: (libc)Error Codes. * EL2HLT: (libc)Error Codes. * EL2NSYNC: (libc)Error Codes. * EL3HLT: (libc)Error Codes. * EL3RST: (libc)Error Codes. * ELIBACC: (libc)Error Codes. * ELIBBAD: (libc)Error Codes. * ELIBEXEC: (libc)Error Codes. * ELIBMAX: (libc)Error Codes. * ELIBSCN: (libc)Error Codes. * ELNRNG: (libc)Error Codes. * ELOOP: (libc)Error Codes. * EMEDIUMTYPE: (libc)Error Codes. * EMFILE: (libc)Error Codes. * EMLINK: (libc)Error Codes. * EMSGSIZE: (libc)Error Codes. * EMULTIHOP: (libc)Error Codes. * ENAMETOOLONG: (libc)Error Codes. * ENAVAIL: (libc)Error Codes. * ENEEDAUTH: (libc)Error Codes. * ENETDOWN: (libc)Error Codes. * ENETRESET: (libc)Error Codes. * ENETUNREACH: (libc)Error Codes. * ENFILE: (libc)Error Codes. * ENOANO: (libc)Error Codes. * ENOBUFS: (libc)Error Codes. * ENOCSI: (libc)Error Codes. * ENODATA: (libc)Error Codes. * ENODEV: (libc)Error Codes. * ENOENT: (libc)Error Codes. * ENOEXEC: (libc)Error Codes. * ENOKEY: (libc)Error Codes. * ENOLCK: (libc)Error Codes. * ENOLINK: (libc)Error Codes. * ENOMEDIUM: (libc)Error Codes. * ENOMEM: (libc)Error Codes. * ENOMSG: (libc)Error Codes. * ENONET: (libc)Error Codes. * ENOPKG: (libc)Error Codes. * ENOPROTOOPT: (libc)Error Codes. * ENOSPC: (libc)Error Codes. * ENOSR: (libc)Error Codes. * ENOSTR: (libc)Error Codes. * ENOSYS: (libc)Error Codes. * ENOTBLK: (libc)Error Codes. * ENOTCONN: (libc)Error Codes. * ENOTDIR: (libc)Error Codes. * ENOTEMPTY: (libc)Error Codes. * ENOTNAM: (libc)Error Codes. * ENOTRECOVERABLE: (libc)Error Codes. * ENOTSOCK: (libc)Error Codes. * ENOTSUP: (libc)Error Codes. * ENOTTY: (libc)Error Codes. * ENOTUNIQ: (libc)Error Codes. * ENXIO: (libc)Error Codes. * EOF: (libc)EOF and Errors. * EOPNOTSUPP: (libc)Error Codes. * EOVERFLOW: (libc)Error Codes. * EOWNERDEAD: (libc)Error Codes. * EPERM: (libc)Error Codes. * EPFNOSUPPORT: (libc)Error Codes. * EPIPE: (libc)Error Codes. * EPROCLIM: (libc)Error Codes. * EPROCUNAVAIL: (libc)Error Codes. * EPROGMISMATCH: (libc)Error Codes. * EPROGUNAVAIL: (libc)Error Codes. * EPROTO: (libc)Error Codes. * EPROTONOSUPPORT: (libc)Error Codes. * EPROTOTYPE: (libc)Error Codes. * EQUIV_CLASS_MAX: (libc)Utility Limits. * ERANGE: (libc)Error Codes. * EREMCHG: (libc)Error Codes. * EREMOTE: (libc)Error Codes. * EREMOTEIO: (libc)Error Codes. * ERESTART: (libc)Error Codes. * ERFKILL: (libc)Error Codes. * EROFS: (libc)Error Codes. * ERPCMISMATCH: (libc)Error Codes. * ESHUTDOWN: (libc)Error Codes. * ESOCKTNOSUPPORT: (libc)Error Codes. * ESPIPE: (libc)Error Codes. * ESRCH: (libc)Error Codes. * ESRMNT: (libc)Error Codes. * ESTALE: (libc)Error Codes. * ESTRPIPE: (libc)Error Codes. * ETIME: (libc)Error Codes. * ETIMEDOUT: (libc)Error Codes. * ETOOMANYREFS: (libc)Error Codes. * ETXTBSY: (libc)Error Codes. * EUCLEAN: (libc)Error Codes. * EUNATCH: (libc)Error Codes. * EUSERS: (libc)Error Codes. * EWOULDBLOCK: (libc)Error Codes. * EXDEV: (libc)Error Codes. * EXFULL: (libc)Error Codes. * EXIT_FAILURE: (libc)Exit Status. * EXIT_SUCCESS: (libc)Exit Status. * EXPR_NEST_MAX: (libc)Utility Limits. * FD_CLOEXEC: (libc)Descriptor Flags. * FD_CLR: (libc)Waiting for I/O. * FD_ISSET: (libc)Waiting for I/O. * FD_SET: (libc)Waiting for I/O. * FD_SETSIZE: (libc)Waiting for I/O. * FD_ZERO: (libc)Waiting for I/O. * FE_SNANS_ALWAYS_SIGNAL: (libc)Infinity and NaN. * FILENAME_MAX: (libc)Limits for Files. * FLUSHO: (libc)Local Modes. * FOPEN_MAX: (libc)Opening Streams. * FP_ILOGB0: (libc)Exponents and Logarithms. * FP_ILOGBNAN: (libc)Exponents and Logarithms. * FP_LLOGB0: (libc)Exponents and Logarithms. * FP_LLOGBNAN: (libc)Exponents and Logarithms. * F_DUPFD: (libc)Duplicating Descriptors. * F_GETFD: (libc)Descriptor Flags. * F_GETFL: (libc)Getting File Status Flags. * F_GETLK: (libc)File Locks. * F_GETOWN: (libc)Interrupt Input. * F_OFD_GETLK: (libc)Open File Description Locks. * F_OFD_SETLK: (libc)Open File Description Locks. * F_OFD_SETLKW: (libc)Open File Description Locks. * F_OK: (libc)Testing File Access. * F_SETFD: (libc)Descriptor Flags. * F_SETFL: (libc)Getting File Status Flags. * F_SETLK: (libc)File Locks. * F_SETLKW: (libc)File Locks. * F_SETOWN: (libc)Interrupt Input. * HUGE_VAL: (libc)Math Error Reporting. * HUGE_VALF: (libc)Math Error Reporting. * HUGE_VALL: (libc)Math Error Reporting. * HUGE_VAL_FN: (libc)Math Error Reporting. * HUGE_VAL_FNx: (libc)Math Error Reporting. * HUPCL: (libc)Control Modes. * I: (libc)Complex Numbers. * ICANON: (libc)Local Modes. * ICRNL: (libc)Input Modes. * IEXTEN: (libc)Local Modes. * IFNAMSIZ: (libc)Interface Naming. * IFTODT: (libc)Directory Entries. * IGNBRK: (libc)Input Modes. * IGNCR: (libc)Input Modes. * IGNPAR: (libc)Input Modes. * IMAXBEL: (libc)Input Modes. * INADDR_ANY: (libc)Host Address Data Type. * INADDR_BROADCAST: (libc)Host Address Data Type. * INADDR_LOOPBACK: (libc)Host Address Data Type. * INADDR_NONE: (libc)Host Address Data Type. * INFINITY: (libc)Infinity and NaN. * INLCR: (libc)Input Modes. * INPCK: (libc)Input Modes. * IPPORT_RESERVED: (libc)Ports. * IPPORT_USERRESERVED: (libc)Ports. * ISIG: (libc)Local Modes. * ISTRIP: (libc)Input Modes. * IXANY: (libc)Input Modes. * IXOFF: (libc)Input Modes. * IXON: (libc)Input Modes. * LINE_MAX: (libc)Utility Limits. * LINK_MAX: (libc)Limits for Files. * L_ctermid: (libc)Identifying the Terminal. * L_cuserid: (libc)Who Logged In. * L_tmpnam: (libc)Temporary Files. * MAXNAMLEN: (libc)Limits for Files. * MAXSYMLINKS: (libc)Symbolic Links. * MAX_CANON: (libc)Limits for Files. * MAX_INPUT: (libc)Limits for Files. * MB_CUR_MAX: (libc)Selecting the Conversion. * MB_LEN_MAX: (libc)Selecting the Conversion. * MDMBUF: (libc)Control Modes. * MSG_DONTROUTE: (libc)Socket Data Options. * MSG_OOB: (libc)Socket Data Options. * MSG_PEEK: (libc)Socket Data Options. * NAME_MAX: (libc)Limits for Files. * NAN: (libc)Infinity and NaN. * NCCS: (libc)Mode Data Types. * NGROUPS_MAX: (libc)General Limits. * NOFLSH: (libc)Local Modes. * NOKERNINFO: (libc)Local Modes. * NSIG: (libc)Standard Signals. * NULL: (libc)Null Pointer Constant. * ONLCR: (libc)Output Modes. * ONOEOT: (libc)Output Modes. * OPEN_MAX: (libc)General Limits. * OPOST: (libc)Output Modes. * OXTABS: (libc)Output Modes. * O_ACCMODE: (libc)Access Modes. * O_APPEND: (libc)Operating Modes. * O_ASYNC: (libc)Operating Modes. * O_CREAT: (libc)Open-time Flags. * O_EXCL: (libc)Open-time Flags. * O_EXEC: (libc)Access Modes. * O_EXLOCK: (libc)Open-time Flags. * O_FSYNC: (libc)Operating Modes. * O_IGNORE_CTTY: (libc)Open-time Flags. * O_NDELAY: (libc)Operating Modes. * O_NOATIME: (libc)Operating Modes. * O_NOCTTY: (libc)Open-time Flags. * O_NOLINK: (libc)Open-time Flags. * O_NONBLOCK: (libc)Open-time Flags. * O_NONBLOCK: (libc)Operating Modes. * O_NOTRANS: (libc)Open-time Flags. * O_RDONLY: (libc)Access Modes. * O_RDWR: (libc)Access Modes. * O_READ: (libc)Access Modes. * O_SHLOCK: (libc)Open-time Flags. * O_SYNC: (libc)Operating Modes. * O_TMPFILE: (libc)Open-time Flags. * O_TRUNC: (libc)Open-time Flags. * O_WRITE: (libc)Access Modes. * O_WRONLY: (libc)Access Modes. * PARENB: (libc)Control Modes. * PARMRK: (libc)Input Modes. * PARODD: (libc)Control Modes. * PATH_MAX: (libc)Limits for Files. * PA_FLAG_MASK: (libc)Parsing a Template String. * PENDIN: (libc)Local Modes. * PF_FILE: (libc)Local Namespace Details. * PF_INET6: (libc)Internet Namespace. * PF_INET: (libc)Internet Namespace. * PF_LOCAL: (libc)Local Namespace Details. * PF_UNIX: (libc)Local Namespace Details. * PIPE_BUF: (libc)Limits for Files. * P_tmpdir: (libc)Temporary Files. * RAND_MAX: (libc)ISO Random. * RE_DUP_MAX: (libc)General Limits. * RLIM_INFINITY: (libc)Limits on Resources. * R_OK: (libc)Testing File Access. * SA_NOCLDSTOP: (libc)Flags for Sigaction. * SA_ONSTACK: (libc)Flags for Sigaction. * SA_RESTART: (libc)Flags for Sigaction. * SEEK_CUR: (libc)File Positioning. * SEEK_END: (libc)File Positioning. * SEEK_SET: (libc)File Positioning. * SIGABRT: (libc)Program Error Signals. * SIGALRM: (libc)Alarm Signals. * SIGBUS: (libc)Program Error Signals. * SIGCHLD: (libc)Job Control Signals. * SIGCLD: (libc)Job Control Signals. * SIGCONT: (libc)Job Control Signals. * SIGEMT: (libc)Program Error Signals. * SIGFPE: (libc)Program Error Signals. * SIGHUP: (libc)Termination Signals. * SIGILL: (libc)Program Error Signals. * SIGINFO: (libc)Miscellaneous Signals. * SIGINT: (libc)Termination Signals. * SIGIO: (libc)Asynchronous I/O Signals. * SIGIOT: (libc)Program Error Signals. * SIGKILL: (libc)Termination Signals. * SIGLOST: (libc)Operation Error Signals. * SIGPIPE: (libc)Operation Error Signals. * SIGPOLL: (libc)Asynchronous I/O Signals. * SIGPROF: (libc)Alarm Signals. * SIGQUIT: (libc)Termination Signals. * SIGSEGV: (libc)Program Error Signals. * SIGSTOP: (libc)Job Control Signals. * SIGSYS: (libc)Program Error Signals. * SIGTERM: (libc)Termination Signals. * SIGTRAP: (libc)Program Error Signals. * SIGTSTP: (libc)Job Control Signals. * SIGTTIN: (libc)Job Control Signals. * SIGTTOU: (libc)Job Control Signals. * SIGURG: (libc)Asynchronous I/O Signals. * SIGUSR1: (libc)Miscellaneous Signals. * SIGUSR2: (libc)Miscellaneous Signals. * SIGVTALRM: (libc)Alarm Signals. * SIGWINCH: (libc)Miscellaneous Signals. * SIGXCPU: (libc)Operation Error Signals. * SIGXFSZ: (libc)Operation Error Signals. * SIG_ERR: (libc)Basic Signal Handling. * SNAN: (libc)Infinity and NaN. * SNANF: (libc)Infinity and NaN. * SNANFN: (libc)Infinity and NaN. * SNANFNx: (libc)Infinity and NaN. * SNANL: (libc)Infinity and NaN. * SOCK_DGRAM: (libc)Communication Styles. * SOCK_RAW: (libc)Communication Styles. * SOCK_RDM: (libc)Communication Styles. * SOCK_SEQPACKET: (libc)Communication Styles. * SOCK_STREAM: (libc)Communication Styles. * SOL_SOCKET: (libc)Socket-Level Options. * SSIZE_MAX: (libc)General Limits. * STREAM_MAX: (libc)General Limits. * SUN_LEN: (libc)Local Namespace Details. * S_IFMT: (libc)Testing File Type. * S_ISBLK: (libc)Testing File Type. * S_ISCHR: (libc)Testing File Type. * S_ISDIR: (libc)Testing File Type. * S_ISFIFO: (libc)Testing File Type. * S_ISLNK: (libc)Testing File Type. * S_ISREG: (libc)Testing File Type. * S_ISSOCK: (libc)Testing File Type. * S_TYPEISMQ: (libc)Testing File Type. * S_TYPEISSEM: (libc)Testing File Type. * S_TYPEISSHM: (libc)Testing File Type. * TMP_MAX: (libc)Temporary Files. * TOSTOP: (libc)Local Modes. * TZNAME_MAX: (libc)General Limits. * VDISCARD: (libc)Other Special. * VDSUSP: (libc)Signal Characters. * VEOF: (libc)Editing Characters. * VEOL2: (libc)Editing Characters. * VEOL: (libc)Editing Characters. * VERASE: (libc)Editing Characters. * VINTR: (libc)Signal Characters. * VKILL: (libc)Editing Characters. * VLNEXT: (libc)Other Special. * VMIN: (libc)Noncanonical Input. * VQUIT: (libc)Signal Characters. * VREPRINT: (libc)Editing Characters. * VSTART: (libc)Start/Stop Characters. * VSTATUS: (libc)Other Special. * VSTOP: (libc)Start/Stop Characters. * VSUSP: (libc)Signal Characters. * VTIME: (libc)Noncanonical Input. * VWERASE: (libc)Editing Characters. * WCHAR_MAX: (libc)Extended Char Intro. * WCHAR_MIN: (libc)Extended Char Intro. * WCOREDUMP: (libc)Process Completion Status. * WEOF: (libc)EOF and Errors. * WEOF: (libc)Extended Char Intro. * WEXITSTATUS: (libc)Process Completion Status. * WIFEXITED: (libc)Process Completion Status. * WIFSIGNALED: (libc)Process Completion Status. * WIFSTOPPED: (libc)Process Completion Status. * WSTOPSIG: (libc)Process Completion Status. * WTERMSIG: (libc)Process Completion Status. * W_OK: (libc)Testing File Access. * X_OK: (libc)Testing File Access. * _Complex_I: (libc)Complex Numbers. * _Exit: (libc)Termination Internals. * _IOFBF: (libc)Controlling Buffering. * _IOLBF: (libc)Controlling Buffering. * _IONBF: (libc)Controlling Buffering. * _Imaginary_I: (libc)Complex Numbers. * _PATH_UTMP: (libc)Manipulating the Database. * _PATH_WTMP: (libc)Manipulating the Database. * _POSIX2_C_DEV: (libc)System Options. * _POSIX2_C_VERSION: (libc)Version Supported. * _POSIX2_FORT_DEV: (libc)System Options. * _POSIX2_FORT_RUN: (libc)System Options. * _POSIX2_LOCALEDEF: (libc)System Options. * _POSIX2_SW_DEV: (libc)System Options. * _POSIX_CHOWN_RESTRICTED: (libc)Options for Files. * _POSIX_JOB_CONTROL: (libc)System Options. * _POSIX_NO_TRUNC: (libc)Options for Files. * _POSIX_SAVED_IDS: (libc)System Options. * _POSIX_VDISABLE: (libc)Options for Files. * _POSIX_VERSION: (libc)Version Supported. * __fbufsize: (libc)Controlling Buffering. * __flbf: (libc)Controlling Buffering. * __fpending: (libc)Controlling Buffering. * __fpurge: (libc)Flushing Buffers. * __freadable: (libc)Opening Streams. * __freading: (libc)Opening Streams. * __fsetlocking: (libc)Streams and Threads. * __fwritable: (libc)Opening Streams. * __fwriting: (libc)Opening Streams. * __gconv_end_fct: (libc)glibc iconv Implementation. * __gconv_fct: (libc)glibc iconv Implementation. * __gconv_init_fct: (libc)glibc iconv Implementation. * __ppc_get_timebase: (libc)PowerPC. * __ppc_get_timebase_freq: (libc)PowerPC. * __ppc_mdoio: (libc)PowerPC. * __ppc_mdoom: (libc)PowerPC. * __ppc_set_ppr_low: (libc)PowerPC. * __ppc_set_ppr_med: (libc)PowerPC. * __ppc_set_ppr_med_high: (libc)PowerPC. * __ppc_set_ppr_med_low: (libc)PowerPC. * __ppc_set_ppr_very_low: (libc)PowerPC. * __ppc_yield: (libc)PowerPC. * __riscv_flush_icache: (libc)RISC-V. * __va_copy: (libc)Argument Macros. * _exit: (libc)Termination Internals. * _flushlbf: (libc)Flushing Buffers. * _tolower: (libc)Case Conversion. * _toupper: (libc)Case Conversion. * a64l: (libc)Encode Binary Data. * abort: (libc)Aborting a Program. * abs: (libc)Absolute Value. * accept: (libc)Accepting Connections. * access: (libc)Testing File Access. * acos: (libc)Inverse Trig Functions. * acosf: (libc)Inverse Trig Functions. * acosfN: (libc)Inverse Trig Functions. * acosfNx: (libc)Inverse Trig Functions. * acosh: (libc)Hyperbolic Functions. * acoshf: (libc)Hyperbolic Functions. * acoshfN: (libc)Hyperbolic Functions. * acoshfNx: (libc)Hyperbolic Functions. * acoshl: (libc)Hyperbolic Functions. * acosl: (libc)Inverse Trig Functions. * addmntent: (libc)mtab. * addseverity: (libc)Adding Severity Classes. * adjtime: (libc)High-Resolution Calendar. * adjtimex: (libc)High-Resolution Calendar. * aio_cancel64: (libc)Cancel AIO Operations. * aio_cancel: (libc)Cancel AIO Operations. * aio_error64: (libc)Status of AIO Operations. * aio_error: (libc)Status of AIO Operations. * aio_fsync64: (libc)Synchronizing AIO Operations. * aio_fsync: (libc)Synchronizing AIO Operations. * aio_init: (libc)Configuration of AIO. * aio_read64: (libc)Asynchronous Reads/Writes. * aio_read: (libc)Asynchronous Reads/Writes. * aio_return64: (libc)Status of AIO Operations. * aio_return: (libc)Status of AIO Operations. * aio_suspend64: (libc)Synchronizing AIO Operations. * aio_suspend: (libc)Synchronizing AIO Operations. * aio_write64: (libc)Asynchronous Reads/Writes. * aio_write: (libc)Asynchronous Reads/Writes. * alarm: (libc)Setting an Alarm. * aligned_alloc: (libc)Aligned Memory Blocks. * alloca: (libc)Variable Size Automatic. * alphasort64: (libc)Scanning Directory Content. * alphasort: (libc)Scanning Directory Content. * argp_error: (libc)Argp Helper Functions. * argp_failure: (libc)Argp Helper Functions. * argp_help: (libc)Argp Help. * argp_parse: (libc)Argp. * argp_state_help: (libc)Argp Helper Functions. * argp_usage: (libc)Argp Helper Functions. * argz_add: (libc)Argz Functions. * argz_add_sep: (libc)Argz Functions. * argz_append: (libc)Argz Functions. * argz_count: (libc)Argz Functions. * argz_create: (libc)Argz Functions. * argz_create_sep: (libc)Argz Functions. * argz_delete: (libc)Argz Functions. * argz_extract: (libc)Argz Functions. * argz_insert: (libc)Argz Functions. * argz_next: (libc)Argz Functions. * argz_replace: (libc)Argz Functions. * argz_stringify: (libc)Argz Functions. * asctime: (libc)Formatting Calendar Time. * asctime_r: (libc)Formatting Calendar Time. * asin: (libc)Inverse Trig Functions. * asinf: (libc)Inverse Trig Functions. * asinfN: (libc)Inverse Trig Functions. * asinfNx: (libc)Inverse Trig Functions. * asinh: (libc)Hyperbolic Functions. * asinhf: (libc)Hyperbolic Functions. * asinhfN: (libc)Hyperbolic Functions. * asinhfNx: (libc)Hyperbolic Functions. * asinhl: (libc)Hyperbolic Functions. * asinl: (libc)Inverse Trig Functions. * asprintf: (libc)Dynamic Output. * assert: (libc)Consistency Checking. * assert_perror: (libc)Consistency Checking. * atan2: (libc)Inverse Trig Functions. * atan2f: (libc)Inverse Trig Functions. * atan2fN: (libc)Inverse Trig Functions. * atan2fNx: (libc)Inverse Trig Functions. * atan2l: (libc)Inverse Trig Functions. * atan: (libc)Inverse Trig Functions. * atanf: (libc)Inverse Trig Functions. * atanfN: (libc)Inverse Trig Functions. * atanfNx: (libc)Inverse Trig Functions. * atanh: (libc)Hyperbolic Functions. * atanhf: (libc)Hyperbolic Functions. * atanhfN: (libc)Hyperbolic Functions. * atanhfNx: (libc)Hyperbolic Functions. * atanhl: (libc)Hyperbolic Functions. * atanl: (libc)Inverse Trig Functions. * atexit: (libc)Cleanups on Exit. * atof: (libc)Parsing of Floats. * atoi: (libc)Parsing of Integers. * atol: (libc)Parsing of Integers. * atoll: (libc)Parsing of Integers. * backtrace: (libc)Backtraces. * backtrace_symbols: (libc)Backtraces. * backtrace_symbols_fd: (libc)Backtraces. * basename: (libc)Finding Tokens in a String. * basename: (libc)Finding Tokens in a String. * bcmp: (libc)String/Array Comparison. * bcopy: (libc)Copying Strings and Arrays. * bind: (libc)Setting Address. * bind_textdomain_codeset: (libc)Charset conversion in gettext. * bindtextdomain: (libc)Locating gettext catalog. * brk: (libc)Resizing the Data Segment. * bsearch: (libc)Array Search Function. * btowc: (libc)Converting a Character. * bzero: (libc)Copying Strings and Arrays. * cabs: (libc)Absolute Value. * cabsf: (libc)Absolute Value. * cabsfN: (libc)Absolute Value. * cabsfNx: (libc)Absolute Value. * cabsl: (libc)Absolute Value. * cacos: (libc)Inverse Trig Functions. * cacosf: (libc)Inverse Trig Functions. * cacosfN: (libc)Inverse Trig Functions. * cacosfNx: (libc)Inverse Trig Functions. * cacosh: (libc)Hyperbolic Functions. * cacoshf: (libc)Hyperbolic Functions. * cacoshfN: (libc)Hyperbolic Functions. * cacoshfNx: (libc)Hyperbolic Functions. * cacoshl: (libc)Hyperbolic Functions. * cacosl: (libc)Inverse Trig Functions. * call_once: (libc)Call Once. * calloc: (libc)Allocating Cleared Space. * canonicalize: (libc)FP Bit Twiddling. * canonicalize_file_name: (libc)Symbolic Links. * canonicalizef: (libc)FP Bit Twiddling. * canonicalizefN: (libc)FP Bit Twiddling. * canonicalizefNx: (libc)FP Bit Twiddling. * canonicalizel: (libc)FP Bit Twiddling. * carg: (libc)Operations on Complex. * cargf: (libc)Operations on Complex. * cargfN: (libc)Operations on Complex. * cargfNx: (libc)Operations on Complex. * cargl: (libc)Operations on Complex. * casin: (libc)Inverse Trig Functions. * casinf: (libc)Inverse Trig Functions. * casinfN: (libc)Inverse Trig Functions. * casinfNx: (libc)Inverse Trig Functions. * casinh: (libc)Hyperbolic Functions. * casinhf: (libc)Hyperbolic Functions. * casinhfN: (libc)Hyperbolic Functions. * casinhfNx: (libc)Hyperbolic Functions. * casinhl: (libc)Hyperbolic Functions. * casinl: (libc)Inverse Trig Functions. * catan: (libc)Inverse Trig Functions. * catanf: (libc)Inverse Trig Functions. * catanfN: (libc)Inverse Trig Functions. * catanfNx: (libc)Inverse Trig Functions. * catanh: (libc)Hyperbolic Functions. * catanhf: (libc)Hyperbolic Functions. * catanhfN: (libc)Hyperbolic Functions. * catanhfNx: (libc)Hyperbolic Functions. * catanhl: (libc)Hyperbolic Functions. * catanl: (libc)Inverse Trig Functions. * catclose: (libc)The catgets Functions. * catgets: (libc)The catgets Functions. * catopen: (libc)The catgets Functions. * cbrt: (libc)Exponents and Logarithms. * cbrtf: (libc)Exponents and Logarithms. * cbrtfN: (libc)Exponents and Logarithms. * cbrtfNx: (libc)Exponents and Logarithms. * cbrtl: (libc)Exponents and Logarithms. * ccos: (libc)Trig Functions. * ccosf: (libc)Trig Functions. * ccosfN: (libc)Trig Functions. * ccosfNx: (libc)Trig Functions. * ccosh: (libc)Hyperbolic Functions. * ccoshf: (libc)Hyperbolic Functions. * ccoshfN: (libc)Hyperbolic Functions. * ccoshfNx: (libc)Hyperbolic Functions. * ccoshl: (libc)Hyperbolic Functions. * ccosl: (libc)Trig Functions. * ceil: (libc)Rounding Functions. * ceilf: (libc)Rounding Functions. * ceilfN: (libc)Rounding Functions. * ceilfNx: (libc)Rounding Functions. * ceill: (libc)Rounding Functions. * cexp: (libc)Exponents and Logarithms. * cexpf: (libc)Exponents and Logarithms. * cexpfN: (libc)Exponents and Logarithms. * cexpfNx: (libc)Exponents and Logarithms. * cexpl: (libc)Exponents and Logarithms. * cfgetispeed: (libc)Line Speed. * cfgetospeed: (libc)Line Speed. * cfmakeraw: (libc)Noncanonical Input. * cfsetispeed: (libc)Line Speed. * cfsetospeed: (libc)Line Speed. * cfsetspeed: (libc)Line Speed. * chdir: (libc)Working Directory. * chmod: (libc)Setting Permissions. * chown: (libc)File Owner. * cimag: (libc)Operations on Complex. * cimagf: (libc)Operations on Complex. * cimagfN: (libc)Operations on Complex. * cimagfNx: (libc)Operations on Complex. * cimagl: (libc)Operations on Complex. * clearenv: (libc)Environment Access. * clearerr: (libc)Error Recovery. * clearerr_unlocked: (libc)Error Recovery. * clock: (libc)CPU Time. * clog10: (libc)Exponents and Logarithms. * clog10f: (libc)Exponents and Logarithms. * clog10fN: (libc)Exponents and Logarithms. * clog10fNx: (libc)Exponents and Logarithms. * clog10l: (libc)Exponents and Logarithms. * clog: (libc)Exponents and Logarithms. * clogf: (libc)Exponents and Logarithms. * clogfN: (libc)Exponents and Logarithms. * clogfNx: (libc)Exponents and Logarithms. * clogl: (libc)Exponents and Logarithms. * close: (libc)Opening and Closing Files. * closedir: (libc)Reading/Closing Directory. * closelog: (libc)closelog. * cnd_broadcast: (libc)ISO C Condition Variables. * cnd_destroy: (libc)ISO C Condition Variables. * cnd_init: (libc)ISO C Condition Variables. * cnd_signal: (libc)ISO C Condition Variables. * cnd_timedwait: (libc)ISO C Condition Variables. * cnd_wait: (libc)ISO C Condition Variables. * confstr: (libc)String Parameters. * conj: (libc)Operations on Complex. * conjf: (libc)Operations on Complex. * conjfN: (libc)Operations on Complex. * conjfNx: (libc)Operations on Complex. * conjl: (libc)Operations on Complex. * connect: (libc)Connecting. * copy_file_range: (libc)Copying File Data. * copysign: (libc)FP Bit Twiddling. * copysignf: (libc)FP Bit Twiddling. * copysignfN: (libc)FP Bit Twiddling. * copysignfNx: (libc)FP Bit Twiddling. * copysignl: (libc)FP Bit Twiddling. * cos: (libc)Trig Functions. * cosf: (libc)Trig Functions. * cosfN: (libc)Trig Functions. * cosfNx: (libc)Trig Functions. * cosh: (libc)Hyperbolic Functions. * coshf: (libc)Hyperbolic Functions. * coshfN: (libc)Hyperbolic Functions. * coshfNx: (libc)Hyperbolic Functions. * coshl: (libc)Hyperbolic Functions. * cosl: (libc)Trig Functions. * cpow: (libc)Exponents and Logarithms. * cpowf: (libc)Exponents and Logarithms. * cpowfN: (libc)Exponents and Logarithms. * cpowfNx: (libc)Exponents and Logarithms. * cpowl: (libc)Exponents and Logarithms. * cproj: (libc)Operations on Complex. * cprojf: (libc)Operations on Complex. * cprojfN: (libc)Operations on Complex. * cprojfNx: (libc)Operations on Complex. * cprojl: (libc)Operations on Complex. * creal: (libc)Operations on Complex. * crealf: (libc)Operations on Complex. * crealfN: (libc)Operations on Complex. * crealfNx: (libc)Operations on Complex. * creall: (libc)Operations on Complex. * creat64: (libc)Opening and Closing Files. * creat: (libc)Opening and Closing Files. * crypt: (libc)Passphrase Storage. * crypt_r: (libc)Passphrase Storage. * csin: (libc)Trig Functions. * csinf: (libc)Trig Functions. * csinfN: (libc)Trig Functions. * csinfNx: (libc)Trig Functions. * csinh: (libc)Hyperbolic Functions. * csinhf: (libc)Hyperbolic Functions. * csinhfN: (libc)Hyperbolic Functions. * csinhfNx: (libc)Hyperbolic Functions. * csinhl: (libc)Hyperbolic Functions. * csinl: (libc)Trig Functions. * csqrt: (libc)Exponents and Logarithms. * csqrtf: (libc)Exponents and Logarithms. * csqrtfN: (libc)Exponents and Logarithms. * csqrtfNx: (libc)Exponents and Logarithms. * csqrtl: (libc)Exponents and Logarithms. * ctan: (libc)Trig Functions. * ctanf: (libc)Trig Functions. * ctanfN: (libc)Trig Functions. * ctanfNx: (libc)Trig Functions. * ctanh: (libc)Hyperbolic Functions. * ctanhf: (libc)Hyperbolic Functions. * ctanhfN: (libc)Hyperbolic Functions. * ctanhfNx: (libc)Hyperbolic Functions. * ctanhl: (libc)Hyperbolic Functions. * ctanl: (libc)Trig Functions. * ctermid: (libc)Identifying the Terminal. * ctime: (libc)Formatting Calendar Time. * ctime_r: (libc)Formatting Calendar Time. * cuserid: (libc)Who Logged In. * daddl: (libc)Misc FP Arithmetic. * dcgettext: (libc)Translation with gettext. * dcngettext: (libc)Advanced gettext functions. * ddivl: (libc)Misc FP Arithmetic. * dgettext: (libc)Translation with gettext. * difftime: (libc)Elapsed Time. * dirfd: (libc)Opening a Directory. * dirname: (libc)Finding Tokens in a String. * div: (libc)Integer Division. * dmull: (libc)Misc FP Arithmetic. * dngettext: (libc)Advanced gettext functions. * drand48: (libc)SVID Random. * drand48_r: (libc)SVID Random. * drem: (libc)Remainder Functions. * dremf: (libc)Remainder Functions. * dreml: (libc)Remainder Functions. * dsubl: (libc)Misc FP Arithmetic. * dup2: (libc)Duplicating Descriptors. * dup: (libc)Duplicating Descriptors. * ecvt: (libc)System V Number Conversion. * ecvt_r: (libc)System V Number Conversion. * endfsent: (libc)fstab. * endgrent: (libc)Scanning All Groups. * endhostent: (libc)Host Names. * endmntent: (libc)mtab. * endnetent: (libc)Networks Database. * endnetgrent: (libc)Lookup Netgroup. * endprotoent: (libc)Protocols Database. * endpwent: (libc)Scanning All Users. * endservent: (libc)Services Database. * endutent: (libc)Manipulating the Database. * endutxent: (libc)XPG Functions. * envz_add: (libc)Envz Functions. * envz_entry: (libc)Envz Functions. * envz_get: (libc)Envz Functions. * envz_merge: (libc)Envz Functions. * envz_remove: (libc)Envz Functions. * envz_strip: (libc)Envz Functions. * erand48: (libc)SVID Random. * erand48_r: (libc)SVID Random. * erf: (libc)Special Functions. * erfc: (libc)Special Functions. * erfcf: (libc)Special Functions. * erfcfN: (libc)Special Functions. * erfcfNx: (libc)Special Functions. * erfcl: (libc)Special Functions. * erff: (libc)Special Functions. * erffN: (libc)Special Functions. * erffNx: (libc)Special Functions. * erfl: (libc)Special Functions. * err: (libc)Error Messages. * errno: (libc)Checking for Errors. * error: (libc)Error Messages. * error_at_line: (libc)Error Messages. * errx: (libc)Error Messages. * execl: (libc)Executing a File. * execle: (libc)Executing a File. * execlp: (libc)Executing a File. * execv: (libc)Executing a File. * execve: (libc)Executing a File. * execvp: (libc)Executing a File. * exit: (libc)Normal Termination. * exp10: (libc)Exponents and Logarithms. * exp10f: (libc)Exponents and Logarithms. * exp10fN: (libc)Exponents and Logarithms. * exp10fNx: (libc)Exponents and Logarithms. * exp10l: (libc)Exponents and Logarithms. * exp2: (libc)Exponents and Logarithms. * exp2f: (libc)Exponents and Logarithms. * exp2fN: (libc)Exponents and Logarithms. * exp2fNx: (libc)Exponents and Logarithms. * exp2l: (libc)Exponents and Logarithms. * exp: (libc)Exponents and Logarithms. * expf: (libc)Exponents and Logarithms. * expfN: (libc)Exponents and Logarithms. * expfNx: (libc)Exponents and Logarithms. * expl: (libc)Exponents and Logarithms. * explicit_bzero: (libc)Erasing Sensitive Data. * expm1: (libc)Exponents and Logarithms. * expm1f: (libc)Exponents and Logarithms. * expm1fN: (libc)Exponents and Logarithms. * expm1fNx: (libc)Exponents and Logarithms. * expm1l: (libc)Exponents and Logarithms. * fMaddfN: (libc)Misc FP Arithmetic. * fMaddfNx: (libc)Misc FP Arithmetic. * fMdivfN: (libc)Misc FP Arithmetic. * fMdivfNx: (libc)Misc FP Arithmetic. * fMmulfN: (libc)Misc FP Arithmetic. * fMmulfNx: (libc)Misc FP Arithmetic. * fMsubfN: (libc)Misc FP Arithmetic. * fMsubfNx: (libc)Misc FP Arithmetic. * fMxaddfN: (libc)Misc FP Arithmetic. * fMxaddfNx: (libc)Misc FP Arithmetic. * fMxdivfN: (libc)Misc FP Arithmetic. * fMxdivfNx: (libc)Misc FP Arithmetic. * fMxmulfN: (libc)Misc FP Arithmetic. * fMxmulfNx: (libc)Misc FP Arithmetic. * fMxsubfN: (libc)Misc FP Arithmetic. * fMxsubfNx: (libc)Misc FP Arithmetic. * fabs: (libc)Absolute Value. * fabsf: (libc)Absolute Value. * fabsfN: (libc)Absolute Value. * fabsfNx: (libc)Absolute Value. * fabsl: (libc)Absolute Value. * fadd: (libc)Misc FP Arithmetic. * faddl: (libc)Misc FP Arithmetic. * fchdir: (libc)Working Directory. * fchmod: (libc)Setting Permissions. * fchown: (libc)File Owner. * fclose: (libc)Closing Streams. * fcloseall: (libc)Closing Streams. * fcntl: (libc)Control Operations. * fcvt: (libc)System V Number Conversion. * fcvt_r: (libc)System V Number Conversion. * fdatasync: (libc)Synchronizing I/O. * fdim: (libc)Misc FP Arithmetic. * fdimf: (libc)Misc FP Arithmetic. * fdimfN: (libc)Misc FP Arithmetic. * fdimfNx: (libc)Misc FP Arithmetic. * fdiml: (libc)Misc FP Arithmetic. * fdiv: (libc)Misc FP Arithmetic. * fdivl: (libc)Misc FP Arithmetic. * fdopen: (libc)Descriptors and Streams. * fdopendir: (libc)Opening a Directory. * feclearexcept: (libc)Status bit operations. * fedisableexcept: (libc)Control Functions. * feenableexcept: (libc)Control Functions. * fegetenv: (libc)Control Functions. * fegetexcept: (libc)Control Functions. * fegetexceptflag: (libc)Status bit operations. * fegetmode: (libc)Control Functions. * fegetround: (libc)Rounding. * feholdexcept: (libc)Control Functions. * feof: (libc)EOF and Errors. * feof_unlocked: (libc)EOF and Errors. * feraiseexcept: (libc)Status bit operations. * ferror: (libc)EOF and Errors. * ferror_unlocked: (libc)EOF and Errors. * fesetenv: (libc)Control Functions. * fesetexcept: (libc)Status bit operations. * fesetexceptflag: (libc)Status bit operations. * fesetmode: (libc)Control Functions. * fesetround: (libc)Rounding. * fetestexcept: (libc)Status bit operations. * fetestexceptflag: (libc)Status bit operations. * feupdateenv: (libc)Control Functions. * fflush: (libc)Flushing Buffers. * fflush_unlocked: (libc)Flushing Buffers. * fgetc: (libc)Character Input. * fgetc_unlocked: (libc)Character Input. * fgetgrent: (libc)Scanning All Groups. * fgetgrent_r: (libc)Scanning All Groups. * fgetpos64: (libc)Portable Positioning. * fgetpos: (libc)Portable Positioning. * fgetpwent: (libc)Scanning All Users. * fgetpwent_r: (libc)Scanning All Users. * fgets: (libc)Line Input. * fgets_unlocked: (libc)Line Input. * fgetwc: (libc)Character Input. * fgetwc_unlocked: (libc)Character Input. * fgetws: (libc)Line Input. * fgetws_unlocked: (libc)Line Input. * fileno: (libc)Descriptors and Streams. * fileno_unlocked: (libc)Descriptors and Streams. * finite: (libc)Floating Point Classes. * finitef: (libc)Floating Point Classes. * finitel: (libc)Floating Point Classes. * flockfile: (libc)Streams and Threads. * floor: (libc)Rounding Functions. * floorf: (libc)Rounding Functions. * floorfN: (libc)Rounding Functions. * floorfNx: (libc)Rounding Functions. * floorl: (libc)Rounding Functions. * fma: (libc)Misc FP Arithmetic. * fmaf: (libc)Misc FP Arithmetic. * fmafN: (libc)Misc FP Arithmetic. * fmafNx: (libc)Misc FP Arithmetic. * fmal: (libc)Misc FP Arithmetic. * fmax: (libc)Misc FP Arithmetic. * fmaxf: (libc)Misc FP Arithmetic. * fmaxfN: (libc)Misc FP Arithmetic. * fmaxfNx: (libc)Misc FP Arithmetic. * fmaxl: (libc)Misc FP Arithmetic. * fmaxmag: (libc)Misc FP Arithmetic. * fmaxmagf: (libc)Misc FP Arithmetic. * fmaxmagfN: (libc)Misc FP Arithmetic. * fmaxmagfNx: (libc)Misc FP Arithmetic. * fmaxmagl: (libc)Misc FP Arithmetic. * fmemopen: (libc)String Streams. * fmin: (libc)Misc FP Arithmetic. * fminf: (libc)Misc FP Arithmetic. * fminfN: (libc)Misc FP Arithmetic. * fminfNx: (libc)Misc FP Arithmetic. * fminl: (libc)Misc FP Arithmetic. * fminmag: (libc)Misc FP Arithmetic. * fminmagf: (libc)Misc FP Arithmetic. * fminmagfN: (libc)Misc FP Arithmetic. * fminmagfNx: (libc)Misc FP Arithmetic. * fminmagl: (libc)Misc FP Arithmetic. * fmod: (libc)Remainder Functions. * fmodf: (libc)Remainder Functions. * fmodfN: (libc)Remainder Functions. * fmodfNx: (libc)Remainder Functions. * fmodl: (libc)Remainder Functions. * fmtmsg: (libc)Printing Formatted Messages. * fmul: (libc)Misc FP Arithmetic. * fmull: (libc)Misc FP Arithmetic. * fnmatch: (libc)Wildcard Matching. * fopen64: (libc)Opening Streams. * fopen: (libc)Opening Streams. * fopencookie: (libc)Streams and Cookies. * fork: (libc)Creating a Process. * forkpty: (libc)Pseudo-Terminal Pairs. * fpathconf: (libc)Pathconf. * fpclassify: (libc)Floating Point Classes. * fprintf: (libc)Formatted Output Functions. * fputc: (libc)Simple Output. * fputc_unlocked: (libc)Simple Output. * fputs: (libc)Simple Output. * fputs_unlocked: (libc)Simple Output. * fputwc: (libc)Simple Output. * fputwc_unlocked: (libc)Simple Output. * fputws: (libc)Simple Output. * fputws_unlocked: (libc)Simple Output. * fread: (libc)Block Input/Output. * fread_unlocked: (libc)Block Input/Output. * free: (libc)Freeing after Malloc. * freopen64: (libc)Opening Streams. * freopen: (libc)Opening Streams. * frexp: (libc)Normalization Functions. * frexpf: (libc)Normalization Functions. * frexpfN: (libc)Normalization Functions. * frexpfNx: (libc)Normalization Functions. * frexpl: (libc)Normalization Functions. * fromfp: (libc)Rounding Functions. * fromfpf: (libc)Rounding Functions. * fromfpfN: (libc)Rounding Functions. * fromfpfNx: (libc)Rounding Functions. * fromfpl: (libc)Rounding Functions. * fromfpx: (libc)Rounding Functions. * fromfpxf: (libc)Rounding Functions. * fromfpxfN: (libc)Rounding Functions. * fromfpxfNx: (libc)Rounding Functions. * fromfpxl: (libc)Rounding Functions. * fscanf: (libc)Formatted Input Functions. * fseek: (libc)File Positioning. * fseeko64: (libc)File Positioning. * fseeko: (libc)File Positioning. * fsetpos64: (libc)Portable Positioning. * fsetpos: (libc)Portable Positioning. * fstat64: (libc)Reading Attributes. * fstat: (libc)Reading Attributes. * fsub: (libc)Misc FP Arithmetic. * fsubl: (libc)Misc FP Arithmetic. * fsync: (libc)Synchronizing I/O. * ftell: (libc)File Positioning. * ftello64: (libc)File Positioning. * ftello: (libc)File Positioning. * ftruncate64: (libc)File Size. * ftruncate: (libc)File Size. * ftrylockfile: (libc)Streams and Threads. * ftw64: (libc)Working with Directory Trees. * ftw: (libc)Working with Directory Trees. * funlockfile: (libc)Streams and Threads. * futimes: (libc)File Times. * fwide: (libc)Streams and I18N. * fwprintf: (libc)Formatted Output Functions. * fwrite: (libc)Block Input/Output. * fwrite_unlocked: (libc)Block Input/Output. * fwscanf: (libc)Formatted Input Functions. * gamma: (libc)Special Functions. * gammaf: (libc)Special Functions. * gammal: (libc)Special Functions. * gcvt: (libc)System V Number Conversion. * get_avphys_pages: (libc)Query Memory Parameters. * get_current_dir_name: (libc)Working Directory. * get_nprocs: (libc)Processor Resources. * get_nprocs_conf: (libc)Processor Resources. * get_phys_pages: (libc)Query Memory Parameters. * getauxval: (libc)Auxiliary Vector. * getc: (libc)Character Input. * getc_unlocked: (libc)Character Input. * getchar: (libc)Character Input. * getchar_unlocked: (libc)Character Input. * getcontext: (libc)System V contexts. * getcwd: (libc)Working Directory. * getdate: (libc)General Time String Parsing. * getdate_r: (libc)General Time String Parsing. * getdelim: (libc)Line Input. * getdomainnname: (libc)Host Identification. * getegid: (libc)Reading Persona. * getentropy: (libc)Unpredictable Bytes. * getenv: (libc)Environment Access. * geteuid: (libc)Reading Persona. * getfsent: (libc)fstab. * getfsfile: (libc)fstab. * getfsspec: (libc)fstab. * getgid: (libc)Reading Persona. * getgrent: (libc)Scanning All Groups. * getgrent_r: (libc)Scanning All Groups. * getgrgid: (libc)Lookup Group. * getgrgid_r: (libc)Lookup Group. * getgrnam: (libc)Lookup Group. * getgrnam_r: (libc)Lookup Group. * getgrouplist: (libc)Setting Groups. * getgroups: (libc)Reading Persona. * gethostbyaddr: (libc)Host Names. * gethostbyaddr_r: (libc)Host Names. * gethostbyname2: (libc)Host Names. * gethostbyname2_r: (libc)Host Names. * gethostbyname: (libc)Host Names. * gethostbyname_r: (libc)Host Names. * gethostent: (libc)Host Names. * gethostid: (libc)Host Identification. * gethostname: (libc)Host Identification. * getitimer: (libc)Setting an Alarm. * getline: (libc)Line Input. * getloadavg: (libc)Processor Resources. * getlogin: (libc)Who Logged In. * getmntent: (libc)mtab. * getmntent_r: (libc)mtab. * getnetbyaddr: (libc)Networks Database. * getnetbyname: (libc)Networks Database. * getnetent: (libc)Networks Database. * getnetgrent: (libc)Lookup Netgroup. * getnetgrent_r: (libc)Lookup Netgroup. * getopt: (libc)Using Getopt. * getopt_long: (libc)Getopt Long Options. * getopt_long_only: (libc)Getopt Long Options. * getpagesize: (libc)Query Memory Parameters. * getpass: (libc)getpass. * getpayload: (libc)FP Bit Twiddling. * getpayloadf: (libc)FP Bit Twiddling. * getpayloadfN: (libc)FP Bit Twiddling. * getpayloadfNx: (libc)FP Bit Twiddling. * getpayloadl: (libc)FP Bit Twiddling. * getpeername: (libc)Who is Connected. * getpgid: (libc)Process Group Functions. * getpgrp: (libc)Process Group Functions. * getpid: (libc)Process Identification. * getppid: (libc)Process Identification. * getpriority: (libc)Traditional Scheduling Functions. * getprotobyname: (libc)Protocols Database. * getprotobynumber: (libc)Protocols Database. * getprotoent: (libc)Protocols Database. * getpt: (libc)Allocation. * getpwent: (libc)Scanning All Users. * getpwent_r: (libc)Scanning All Users. * getpwnam: (libc)Lookup User. * getpwnam_r: (libc)Lookup User. * getpwuid: (libc)Lookup User. * getpwuid_r: (libc)Lookup User. * getrandom: (libc)Unpredictable Bytes. * getrlimit64: (libc)Limits on Resources. * getrlimit: (libc)Limits on Resources. * getrusage: (libc)Resource Usage. * gets: (libc)Line Input. * getservbyname: (libc)Services Database. * getservbyport: (libc)Services Database. * getservent: (libc)Services Database. * getsid: (libc)Process Group Functions. * getsockname: (libc)Reading Address. * getsockopt: (libc)Socket Option Functions. * getsubopt: (libc)Suboptions. * gettext: (libc)Translation with gettext. * gettimeofday: (libc)High-Resolution Calendar. * getuid: (libc)Reading Persona. * getumask: (libc)Setting Permissions. * getutent: (libc)Manipulating the Database. * getutent_r: (libc)Manipulating the Database. * getutid: (libc)Manipulating the Database. * getutid_r: (libc)Manipulating the Database. * getutline: (libc)Manipulating the Database. * getutline_r: (libc)Manipulating the Database. * getutmp: (libc)XPG Functions. * getutmpx: (libc)XPG Functions. * getutxent: (libc)XPG Functions. * getutxid: (libc)XPG Functions. * getutxline: (libc)XPG Functions. * getw: (libc)Character Input. * getwc: (libc)Character Input. * getwc_unlocked: (libc)Character Input. * getwchar: (libc)Character Input. * getwchar_unlocked: (libc)Character Input. * getwd: (libc)Working Directory. * glob64: (libc)Calling Glob. * glob: (libc)Calling Glob. * globfree64: (libc)More Flags for Globbing. * globfree: (libc)More Flags for Globbing. * gmtime: (libc)Broken-down Time. * gmtime_r: (libc)Broken-down Time. * grantpt: (libc)Allocation. * gsignal: (libc)Signaling Yourself. * gtty: (libc)BSD Terminal Modes. * hasmntopt: (libc)mtab. * hcreate: (libc)Hash Search Function. * hcreate_r: (libc)Hash Search Function. * hdestroy: (libc)Hash Search Function. * hdestroy_r: (libc)Hash Search Function. * hsearch: (libc)Hash Search Function. * hsearch_r: (libc)Hash Search Function. * htonl: (libc)Byte Order. * htons: (libc)Byte Order. * hypot: (libc)Exponents and Logarithms. * hypotf: (libc)Exponents and Logarithms. * hypotfN: (libc)Exponents and Logarithms. * hypotfNx: (libc)Exponents and Logarithms. * hypotl: (libc)Exponents and Logarithms. * iconv: (libc)Generic Conversion Interface. * iconv_close: (libc)Generic Conversion Interface. * iconv_open: (libc)Generic Conversion Interface. * if_freenameindex: (libc)Interface Naming. * if_indextoname: (libc)Interface Naming. * if_nameindex: (libc)Interface Naming. * if_nametoindex: (libc)Interface Naming. * ilogb: (libc)Exponents and Logarithms. * ilogbf: (libc)Exponents and Logarithms. * ilogbfN: (libc)Exponents and Logarithms. * ilogbfNx: (libc)Exponents and Logarithms. * ilogbl: (libc)Exponents and Logarithms. * imaxabs: (libc)Absolute Value. * imaxdiv: (libc)Integer Division. * in6addr_any: (libc)Host Address Data Type. * in6addr_loopback: (libc)Host Address Data Type. * index: (libc)Search Functions. * inet_addr: (libc)Host Address Functions. * inet_aton: (libc)Host Address Functions. * inet_lnaof: (libc)Host Address Functions. * inet_makeaddr: (libc)Host Address Functions. * inet_netof: (libc)Host Address Functions. * inet_network: (libc)Host Address Functions. * inet_ntoa: (libc)Host Address Functions. * inet_ntop: (libc)Host Address Functions. * inet_pton: (libc)Host Address Functions. * initgroups: (libc)Setting Groups. * initstate: (libc)BSD Random. * initstate_r: (libc)BSD Random. * innetgr: (libc)Netgroup Membership. * ioctl: (libc)IOCTLs. * isalnum: (libc)Classification of Characters. * isalpha: (libc)Classification of Characters. * isascii: (libc)Classification of Characters. * isatty: (libc)Is It a Terminal. * isblank: (libc)Classification of Characters. * iscanonical: (libc)Floating Point Classes. * iscntrl: (libc)Classification of Characters. * isdigit: (libc)Classification of Characters. * iseqsig: (libc)FP Comparison Functions. * isfinite: (libc)Floating Point Classes. * isgraph: (libc)Classification of Characters. * isgreater: (libc)FP Comparison Functions. * isgreaterequal: (libc)FP Comparison Functions. * isinf: (libc)Floating Point Classes. * isinff: (libc)Floating Point Classes. * isinfl: (libc)Floating Point Classes. * isless: (libc)FP Comparison Functions. * islessequal: (libc)FP Comparison Functions. * islessgreater: (libc)FP Comparison Functions. * islower: (libc)Classification of Characters. * isnan: (libc)Floating Point Classes. * isnan: (libc)Floating Point Classes. * isnanf: (libc)Floating Point Classes. * isnanl: (libc)Floating Point Classes. * isnormal: (libc)Floating Point Classes. * isprint: (libc)Classification of Characters. * ispunct: (libc)Classification of Characters. * issignaling: (libc)Floating Point Classes. * isspace: (libc)Classification of Characters. * issubnormal: (libc)Floating Point Classes. * isunordered: (libc)FP Comparison Functions. * isupper: (libc)Classification of Characters. * iswalnum: (libc)Classification of Wide Characters. * iswalpha: (libc)Classification of Wide Characters. * iswblank: (libc)Classification of Wide Characters. * iswcntrl: (libc)Classification of Wide Characters. * iswctype: (libc)Classification of Wide Characters. * iswdigit: (libc)Classification of Wide Characters. * iswgraph: (libc)Classification of Wide Characters. * iswlower: (libc)Classification of Wide Characters. * iswprint: (libc)Classification of Wide Characters. * iswpunct: (libc)Classification of Wide Characters. * iswspace: (libc)Classification of Wide Characters. * iswupper: (libc)Classification of Wide Characters. * iswxdigit: (libc)Classification of Wide Characters. * isxdigit: (libc)Classification of Characters. * iszero: (libc)Floating Point Classes. * j0: (libc)Special Functions. * j0f: (libc)Special Functions. * j0fN: (libc)Special Functions. * j0fNx: (libc)Special Functions. * j0l: (libc)Special Functions. * j1: (libc)Special Functions. * j1f: (libc)Special Functions. * j1fN: (libc)Special Functions. * j1fNx: (libc)Special Functions. * j1l: (libc)Special Functions. * jn: (libc)Special Functions. * jnf: (libc)Special Functions. * jnfN: (libc)Special Functions. * jnfNx: (libc)Special Functions. * jnl: (libc)Special Functions. * jrand48: (libc)SVID Random. * jrand48_r: (libc)SVID Random. * kill: (libc)Signaling Another Process. * killpg: (libc)Signaling Another Process. * l64a: (libc)Encode Binary Data. * labs: (libc)Absolute Value. * lcong48: (libc)SVID Random. * lcong48_r: (libc)SVID Random. * ldexp: (libc)Normalization Functions. * ldexpf: (libc)Normalization Functions. * ldexpfN: (libc)Normalization Functions. * ldexpfNx: (libc)Normalization Functions. * ldexpl: (libc)Normalization Functions. * ldiv: (libc)Integer Division. * lfind: (libc)Array Search Function. * lgamma: (libc)Special Functions. * lgamma_r: (libc)Special Functions. * lgammaf: (libc)Special Functions. * lgammafN: (libc)Special Functions. * lgammafN_r: (libc)Special Functions. * lgammafNx: (libc)Special Functions. * lgammafNx_r: (libc)Special Functions. * lgammaf_r: (libc)Special Functions. * lgammal: (libc)Special Functions. * lgammal_r: (libc)Special Functions. * link: (libc)Hard Links. * linkat: (libc)Hard Links. * lio_listio64: (libc)Asynchronous Reads/Writes. * lio_listio: (libc)Asynchronous Reads/Writes. * listen: (libc)Listening. * llabs: (libc)Absolute Value. * lldiv: (libc)Integer Division. * llogb: (libc)Exponents and Logarithms. * llogbf: (libc)Exponents and Logarithms. * llogbfN: (libc)Exponents and Logarithms. * llogbfNx: (libc)Exponents and Logarithms. * llogbl: (libc)Exponents and Logarithms. * llrint: (libc)Rounding Functions. * llrintf: (libc)Rounding Functions. * llrintfN: (libc)Rounding Functions. * llrintfNx: (libc)Rounding Functions. * llrintl: (libc)Rounding Functions. * llround: (libc)Rounding Functions. * llroundf: (libc)Rounding Functions. * llroundfN: (libc)Rounding Functions. * llroundfNx: (libc)Rounding Functions. * llroundl: (libc)Rounding Functions. * localeconv: (libc)The Lame Way to Locale Data. * localtime: (libc)Broken-down Time. * localtime_r: (libc)Broken-down Time. * log10: (libc)Exponents and Logarithms. * log10f: (libc)Exponents and Logarithms. * log10fN: (libc)Exponents and Logarithms. * log10fNx: (libc)Exponents and Logarithms. * log10l: (libc)Exponents and Logarithms. * log1p: (libc)Exponents and Logarithms. * log1pf: (libc)Exponents and Logarithms. * log1pfN: (libc)Exponents and Logarithms. * log1pfNx: (libc)Exponents and Logarithms. * log1pl: (libc)Exponents and Logarithms. * log2: (libc)Exponents and Logarithms. * log2f: (libc)Exponents and Logarithms. * log2fN: (libc)Exponents and Logarithms. * log2fNx: (libc)Exponents and Logarithms. * log2l: (libc)Exponents and Logarithms. * log: (libc)Exponents and Logarithms. * logb: (libc)Exponents and Logarithms. * logbf: (libc)Exponents and Logarithms. * logbfN: (libc)Exponents and Logarithms. * logbfNx: (libc)Exponents and Logarithms. * logbl: (libc)Exponents and Logarithms. * logf: (libc)Exponents and Logarithms. * logfN: (libc)Exponents and Logarithms. * logfNx: (libc)Exponents and Logarithms. * login: (libc)Logging In and Out. * login_tty: (libc)Logging In and Out. * logl: (libc)Exponents and Logarithms. * logout: (libc)Logging In and Out. * logwtmp: (libc)Logging In and Out. * longjmp: (libc)Non-Local Details. * lrand48: (libc)SVID Random. * lrand48_r: (libc)SVID Random. * lrint: (libc)Rounding Functions. * lrintf: (libc)Rounding Functions. * lrintfN: (libc)Rounding Functions. * lrintfNx: (libc)Rounding Functions. * lrintl: (libc)Rounding Functions. * lround: (libc)Rounding Functions. * lroundf: (libc)Rounding Functions. * lroundfN: (libc)Rounding Functions. * lroundfNx: (libc)Rounding Functions. * lroundl: (libc)Rounding Functions. * lsearch: (libc)Array Search Function. * lseek64: (libc)File Position Primitive. * lseek: (libc)File Position Primitive. * lstat64: (libc)Reading Attributes. * lstat: (libc)Reading Attributes. * lutimes: (libc)File Times. * madvise: (libc)Memory-mapped I/O. * makecontext: (libc)System V contexts. * mallinfo: (libc)Statistics of Malloc. * malloc: (libc)Basic Allocation. * mallopt: (libc)Malloc Tunable Parameters. * mblen: (libc)Non-reentrant Character Conversion. * mbrlen: (libc)Converting a Character. * mbrtowc: (libc)Converting a Character. * mbsinit: (libc)Keeping the state. * mbsnrtowcs: (libc)Converting Strings. * mbsrtowcs: (libc)Converting Strings. * mbstowcs: (libc)Non-reentrant String Conversion. * mbtowc: (libc)Non-reentrant Character Conversion. * mcheck: (libc)Heap Consistency Checking. * memalign: (libc)Aligned Memory Blocks. * memccpy: (libc)Copying Strings and Arrays. * memchr: (libc)Search Functions. * memcmp: (libc)String/Array Comparison. * memcpy: (libc)Copying Strings and Arrays. * memfd_create: (libc)Memory-mapped I/O. * memfrob: (libc)Obfuscating Data. * memmem: (libc)Search Functions. * memmove: (libc)Copying Strings and Arrays. * mempcpy: (libc)Copying Strings and Arrays. * memrchr: (libc)Search Functions. * memset: (libc)Copying Strings and Arrays. * mkdir: (libc)Creating Directories. * mkdtemp: (libc)Temporary Files. * mkfifo: (libc)FIFO Special Files. * mknod: (libc)Making Special Files. * mkstemp: (libc)Temporary Files. * mktemp: (libc)Temporary Files. * mktime: (libc)Broken-down Time. * mlock2: (libc)Page Lock Functions. * mlock: (libc)Page Lock Functions. * mlockall: (libc)Page Lock Functions. * mmap64: (libc)Memory-mapped I/O. * mmap: (libc)Memory-mapped I/O. * modf: (libc)Rounding Functions. * modff: (libc)Rounding Functions. * modffN: (libc)Rounding Functions. * modffNx: (libc)Rounding Functions. * modfl: (libc)Rounding Functions. * mount: (libc)Mount-Unmount-Remount. * mprobe: (libc)Heap Consistency Checking. * mprotect: (libc)Memory Protection. * mrand48: (libc)SVID Random. * mrand48_r: (libc)SVID Random. * mremap: (libc)Memory-mapped I/O. * msync: (libc)Memory-mapped I/O. * mtrace: (libc)Tracing malloc. * mtx_destroy: (libc)ISO C Mutexes. * mtx_init: (libc)ISO C Mutexes. * mtx_lock: (libc)ISO C Mutexes. * mtx_timedlock: (libc)ISO C Mutexes. * mtx_trylock: (libc)ISO C Mutexes. * mtx_unlock: (libc)ISO C Mutexes. * munlock: (libc)Page Lock Functions. * munlockall: (libc)Page Lock Functions. * munmap: (libc)Memory-mapped I/O. * muntrace: (libc)Tracing malloc. * nan: (libc)FP Bit Twiddling. * nanf: (libc)FP Bit Twiddling. * nanfN: (libc)FP Bit Twiddling. * nanfNx: (libc)FP Bit Twiddling. * nanl: (libc)FP Bit Twiddling. * nanosleep: (libc)Sleeping. * nearbyint: (libc)Rounding Functions. * nearbyintf: (libc)Rounding Functions. * nearbyintfN: (libc)Rounding Functions. * nearbyintfNx: (libc)Rounding Functions. * nearbyintl: (libc)Rounding Functions. * nextafter: (libc)FP Bit Twiddling. * nextafterf: (libc)FP Bit Twiddling. * nextafterfN: (libc)FP Bit Twiddling. * nextafterfNx: (libc)FP Bit Twiddling. * nextafterl: (libc)FP Bit Twiddling. * nextdown: (libc)FP Bit Twiddling. * nextdownf: (libc)FP Bit Twiddling. * nextdownfN: (libc)FP Bit Twiddling. * nextdownfNx: (libc)FP Bit Twiddling. * nextdownl: (libc)FP Bit Twiddling. * nexttoward: (libc)FP Bit Twiddling. * nexttowardf: (libc)FP Bit Twiddling. * nexttowardl: (libc)FP Bit Twiddling. * nextup: (libc)FP Bit Twiddling. * nextupf: (libc)FP Bit Twiddling. * nextupfN: (libc)FP Bit Twiddling. * nextupfNx: (libc)FP Bit Twiddling. * nextupl: (libc)FP Bit Twiddling. * nftw64: (libc)Working with Directory Trees. * nftw: (libc)Working with Directory Trees. * ngettext: (libc)Advanced gettext functions. * nice: (libc)Traditional Scheduling Functions. * nl_langinfo: (libc)The Elegant and Fast Way. * nrand48: (libc)SVID Random. * nrand48_r: (libc)SVID Random. * ntohl: (libc)Byte Order. * ntohs: (libc)Byte Order. * ntp_adjtime: (libc)High Accuracy Clock. * ntp_gettime: (libc)High Accuracy Clock. * obstack_1grow: (libc)Growing Objects. * obstack_1grow_fast: (libc)Extra Fast Growing. * obstack_alignment_mask: (libc)Obstacks Data Alignment. * obstack_alloc: (libc)Allocation in an Obstack. * obstack_base: (libc)Status of an Obstack. * obstack_blank: (libc)Growing Objects. * obstack_blank_fast: (libc)Extra Fast Growing. * obstack_chunk_size: (libc)Obstack Chunks. * obstack_copy0: (libc)Allocation in an Obstack. * obstack_copy: (libc)Allocation in an Obstack. * obstack_finish: (libc)Growing Objects. * obstack_free: (libc)Freeing Obstack Objects. * obstack_grow0: (libc)Growing Objects. * obstack_grow: (libc)Growing Objects. * obstack_init: (libc)Preparing for Obstacks. * obstack_int_grow: (libc)Growing Objects. * obstack_int_grow_fast: (libc)Extra Fast Growing. * obstack_next_free: (libc)Status of an Obstack. * obstack_object_size: (libc)Growing Objects. * obstack_object_size: (libc)Status of an Obstack. * obstack_printf: (libc)Dynamic Output. * obstack_ptr_grow: (libc)Growing Objects. * obstack_ptr_grow_fast: (libc)Extra Fast Growing. * obstack_room: (libc)Extra Fast Growing. * obstack_vprintf: (libc)Variable Arguments Output. * offsetof: (libc)Structure Measurement. * on_exit: (libc)Cleanups on Exit. * open64: (libc)Opening and Closing Files. * open: (libc)Opening and Closing Files. * open_memstream: (libc)String Streams. * opendir: (libc)Opening a Directory. * openlog: (libc)openlog. * openpty: (libc)Pseudo-Terminal Pairs. * parse_printf_format: (libc)Parsing a Template String. * pathconf: (libc)Pathconf. * pause: (libc)Using Pause. * pclose: (libc)Pipe to a Subprocess. * perror: (libc)Error Messages. * pipe: (libc)Creating a Pipe. * pkey_alloc: (libc)Memory Protection. * pkey_free: (libc)Memory Protection. * pkey_get: (libc)Memory Protection. * pkey_mprotect: (libc)Memory Protection. * pkey_set: (libc)Memory Protection. * popen: (libc)Pipe to a Subprocess. * posix_fallocate64: (libc)Storage Allocation. * posix_fallocate: (libc)Storage Allocation. * posix_memalign: (libc)Aligned Memory Blocks. * pow: (libc)Exponents and Logarithms. * powf: (libc)Exponents and Logarithms. * powfN: (libc)Exponents and Logarithms. * powfNx: (libc)Exponents and Logarithms. * powl: (libc)Exponents and Logarithms. * pread64: (libc)I/O Primitives. * pread: (libc)I/O Primitives. * preadv2: (libc)Scatter-Gather. * preadv64: (libc)Scatter-Gather. * preadv64v2: (libc)Scatter-Gather. * preadv: (libc)Scatter-Gather. * printf: (libc)Formatted Output Functions. * printf_size: (libc)Predefined Printf Handlers. * printf_size_info: (libc)Predefined Printf Handlers. * psignal: (libc)Signal Messages. * pthread_getattr_default_np: (libc)Default Thread Attributes. * pthread_getspecific: (libc)Thread-specific Data. * pthread_key_create: (libc)Thread-specific Data. * pthread_key_delete: (libc)Thread-specific Data. * pthread_setattr_default_np: (libc)Default Thread Attributes. * pthread_setspecific: (libc)Thread-specific Data. * ptsname: (libc)Allocation. * ptsname_r: (libc)Allocation. * putc: (libc)Simple Output. * putc_unlocked: (libc)Simple Output. * putchar: (libc)Simple Output. * putchar_unlocked: (libc)Simple Output. * putenv: (libc)Environment Access. * putpwent: (libc)Writing a User Entry. * puts: (libc)Simple Output. * pututline: (libc)Manipulating the Database. * pututxline: (libc)XPG Functions. * putw: (libc)Simple Output. * putwc: (libc)Simple Output. * putwc_unlocked: (libc)Simple Output. * putwchar: (libc)Simple Output. * putwchar_unlocked: (libc)Simple Output. * pwrite64: (libc)I/O Primitives. * pwrite: (libc)I/O Primitives. * pwritev2: (libc)Scatter-Gather. * pwritev64: (libc)Scatter-Gather. * pwritev64v2: (libc)Scatter-Gather. * pwritev: (libc)Scatter-Gather. * qecvt: (libc)System V Number Conversion. * qecvt_r: (libc)System V Number Conversion. * qfcvt: (libc)System V Number Conversion. * qfcvt_r: (libc)System V Number Conversion. * qgcvt: (libc)System V Number Conversion. * qsort: (libc)Array Sort Function. * raise: (libc)Signaling Yourself. * rand: (libc)ISO Random. * rand_r: (libc)ISO Random. * random: (libc)BSD Random. * random_r: (libc)BSD Random. * rawmemchr: (libc)Search Functions. * read: (libc)I/O Primitives. * readdir64: (libc)Reading/Closing Directory. * readdir64_r: (libc)Reading/Closing Directory. * readdir: (libc)Reading/Closing Directory. * readdir_r: (libc)Reading/Closing Directory. * readlink: (libc)Symbolic Links. * readv: (libc)Scatter-Gather. * realloc: (libc)Changing Block Size. * reallocarray: (libc)Changing Block Size. * realpath: (libc)Symbolic Links. * recv: (libc)Receiving Data. * recvfrom: (libc)Receiving Datagrams. * recvmsg: (libc)Receiving Datagrams. * regcomp: (libc)POSIX Regexp Compilation. * regerror: (libc)Regexp Cleanup. * regexec: (libc)Matching POSIX Regexps. * regfree: (libc)Regexp Cleanup. * register_printf_function: (libc)Registering New Conversions. * remainder: (libc)Remainder Functions. * remainderf: (libc)Remainder Functions. * remainderfN: (libc)Remainder Functions. * remainderfNx: (libc)Remainder Functions. * remainderl: (libc)Remainder Functions. * remove: (libc)Deleting Files. * rename: (libc)Renaming Files. * rewind: (libc)File Positioning. * rewinddir: (libc)Random Access Directory. * rindex: (libc)Search Functions. * rint: (libc)Rounding Functions. * rintf: (libc)Rounding Functions. * rintfN: (libc)Rounding Functions. * rintfNx: (libc)Rounding Functions. * rintl: (libc)Rounding Functions. * rmdir: (libc)Deleting Files. * round: (libc)Rounding Functions. * roundeven: (libc)Rounding Functions. * roundevenf: (libc)Rounding Functions. * roundevenfN: (libc)Rounding Functions. * roundevenfNx: (libc)Rounding Functions. * roundevenl: (libc)Rounding Functions. * roundf: (libc)Rounding Functions. * roundfN: (libc)Rounding Functions. * roundfNx: (libc)Rounding Functions. * roundl: (libc)Rounding Functions. * rpmatch: (libc)Yes-or-No Questions. * sbrk: (libc)Resizing the Data Segment. * scalb: (libc)Normalization Functions. * scalbf: (libc)Normalization Functions. * scalbl: (libc)Normalization Functions. * scalbln: (libc)Normalization Functions. * scalblnf: (libc)Normalization Functions. * scalblnfN: (libc)Normalization Functions. * scalblnfNx: (libc)Normalization Functions. * scalblnl: (libc)Normalization Functions. * scalbn: (libc)Normalization Functions. * scalbnf: (libc)Normalization Functions. * scalbnfN: (libc)Normalization Functions. * scalbnfNx: (libc)Normalization Functions. * scalbnl: (libc)Normalization Functions. * scandir64: (libc)Scanning Directory Content. * scandir: (libc)Scanning Directory Content. * scanf: (libc)Formatted Input Functions. * sched_get_priority_max: (libc)Basic Scheduling Functions. * sched_get_priority_min: (libc)Basic Scheduling Functions. * sched_getaffinity: (libc)CPU Affinity. * sched_getparam: (libc)Basic Scheduling Functions. * sched_getscheduler: (libc)Basic Scheduling Functions. * sched_rr_get_interval: (libc)Basic Scheduling Functions. * sched_setaffinity: (libc)CPU Affinity. * sched_setparam: (libc)Basic Scheduling Functions. * sched_setscheduler: (libc)Basic Scheduling Functions. * sched_yield: (libc)Basic Scheduling Functions. * secure_getenv: (libc)Environment Access. * seed48: (libc)SVID Random. * seed48_r: (libc)SVID Random. * seekdir: (libc)Random Access Directory. * select: (libc)Waiting for I/O. * sem_close: (libc)Semaphores. * sem_destroy: (libc)Semaphores. * sem_getvalue: (libc)Semaphores. * sem_init: (libc)Semaphores. * sem_open: (libc)Semaphores. * sem_post: (libc)Semaphores. * sem_timedwait: (libc)Semaphores. * sem_trywait: (libc)Semaphores. * sem_unlink: (libc)Semaphores. * sem_wait: (libc)Semaphores. * semctl: (libc)Semaphores. * semget: (libc)Semaphores. * semop: (libc)Semaphores. * semtimedop: (libc)Semaphores. * send: (libc)Sending Data. * sendmsg: (libc)Receiving Datagrams. * sendto: (libc)Sending Datagrams. * setbuf: (libc)Controlling Buffering. * setbuffer: (libc)Controlling Buffering. * setcontext: (libc)System V contexts. * setdomainname: (libc)Host Identification. * setegid: (libc)Setting Groups. * setenv: (libc)Environment Access. * seteuid: (libc)Setting User ID. * setfsent: (libc)fstab. * setgid: (libc)Setting Groups. * setgrent: (libc)Scanning All Groups. * setgroups: (libc)Setting Groups. * sethostent: (libc)Host Names. * sethostid: (libc)Host Identification. * sethostname: (libc)Host Identification. * setitimer: (libc)Setting an Alarm. * setjmp: (libc)Non-Local Details. * setlinebuf: (libc)Controlling Buffering. * setlocale: (libc)Setting the Locale. * setlogmask: (libc)setlogmask. * setmntent: (libc)mtab. * setnetent: (libc)Networks Database. * setnetgrent: (libc)Lookup Netgroup. * setpayload: (libc)FP Bit Twiddling. * setpayloadf: (libc)FP Bit Twiddling. * setpayloadfN: (libc)FP Bit Twiddling. * setpayloadfNx: (libc)FP Bit Twiddling. * setpayloadl: (libc)FP Bit Twiddling. * setpayloadsig: (libc)FP Bit Twiddling. * setpayloadsigf: (libc)FP Bit Twiddling. * setpayloadsigfN: (libc)FP Bit Twiddling. * setpayloadsigfNx: (libc)FP Bit Twiddling. * setpayloadsigl: (libc)FP Bit Twiddling. * setpgid: (libc)Process Group Functions. * setpgrp: (libc)Process Group Functions. * setpriority: (libc)Traditional Scheduling Functions. * setprotoent: (libc)Protocols Database. * setpwent: (libc)Scanning All Users. * setregid: (libc)Setting Groups. * setreuid: (libc)Setting User ID. * setrlimit64: (libc)Limits on Resources. * setrlimit: (libc)Limits on Resources. * setservent: (libc)Services Database. * setsid: (libc)Process Group Functions. * setsockopt: (libc)Socket Option Functions. * setstate: (libc)BSD Random. * setstate_r: (libc)BSD Random. * settimeofday: (libc)High-Resolution Calendar. * setuid: (libc)Setting User ID. * setutent: (libc)Manipulating the Database. * setutxent: (libc)XPG Functions. * setvbuf: (libc)Controlling Buffering. * shm_open: (libc)Memory-mapped I/O. * shm_unlink: (libc)Memory-mapped I/O. * shutdown: (libc)Closing a Socket. * sigaction: (libc)Advanced Signal Handling. * sigaddset: (libc)Signal Sets. * sigaltstack: (libc)Signal Stack. * sigblock: (libc)BSD Signal Handling. * sigdelset: (libc)Signal Sets. * sigemptyset: (libc)Signal Sets. * sigfillset: (libc)Signal Sets. * siginterrupt: (libc)BSD Signal Handling. * sigismember: (libc)Signal Sets. * siglongjmp: (libc)Non-Local Exits and Signals. * sigmask: (libc)BSD Signal Handling. * signal: (libc)Basic Signal Handling. * signbit: (libc)FP Bit Twiddling. * significand: (libc)Normalization Functions. * significandf: (libc)Normalization Functions. * significandl: (libc)Normalization Functions. * sigpause: (libc)BSD Signal Handling. * sigpending: (libc)Checking for Pending Signals. * sigprocmask: (libc)Process Signal Mask. * sigsetjmp: (libc)Non-Local Exits and Signals. * sigsetmask: (libc)BSD Signal Handling. * sigstack: (libc)Signal Stack. * sigsuspend: (libc)Sigsuspend. * sin: (libc)Trig Functions. * sincos: (libc)Trig Functions. * sincosf: (libc)Trig Functions. * sincosfN: (libc)Trig Functions. * sincosfNx: (libc)Trig Functions. * sincosl: (libc)Trig Functions. * sinf: (libc)Trig Functions. * sinfN: (libc)Trig Functions. * sinfNx: (libc)Trig Functions. * sinh: (libc)Hyperbolic Functions. * sinhf: (libc)Hyperbolic Functions. * sinhfN: (libc)Hyperbolic Functions. * sinhfNx: (libc)Hyperbolic Functions. * sinhl: (libc)Hyperbolic Functions. * sinl: (libc)Trig Functions. * sleep: (libc)Sleeping. * snprintf: (libc)Formatted Output Functions. * socket: (libc)Creating a Socket. * socketpair: (libc)Socket Pairs. * sprintf: (libc)Formatted Output Functions. * sqrt: (libc)Exponents and Logarithms. * sqrtf: (libc)Exponents and Logarithms. * sqrtfN: (libc)Exponents and Logarithms. * sqrtfNx: (libc)Exponents and Logarithms. * sqrtl: (libc)Exponents and Logarithms. * srand48: (libc)SVID Random. * srand48_r: (libc)SVID Random. * srand: (libc)ISO Random. * srandom: (libc)BSD Random. * srandom_r: (libc)BSD Random. * sscanf: (libc)Formatted Input Functions. * ssignal: (libc)Basic Signal Handling. * stat64: (libc)Reading Attributes. * stat: (libc)Reading Attributes. * stime: (libc)Simple Calendar Time. * stpcpy: (libc)Copying Strings and Arrays. * stpncpy: (libc)Truncating Strings. * strcasecmp: (libc)String/Array Comparison. * strcasestr: (libc)Search Functions. * strcat: (libc)Concatenating Strings. * strchr: (libc)Search Functions. * strchrnul: (libc)Search Functions. * strcmp: (libc)String/Array Comparison. * strcoll: (libc)Collation Functions. * strcpy: (libc)Copying Strings and Arrays. * strcspn: (libc)Search Functions. * strdup: (libc)Copying Strings and Arrays. * strdupa: (libc)Copying Strings and Arrays. * strerror: (libc)Error Messages. * strerror_r: (libc)Error Messages. * strfmon: (libc)Formatting Numbers. * strfromd: (libc)Printing of Floats. * strfromf: (libc)Printing of Floats. * strfromfN: (libc)Printing of Floats. * strfromfNx: (libc)Printing of Floats. * strfroml: (libc)Printing of Floats. * strfry: (libc)Shuffling Bytes. * strftime: (libc)Formatting Calendar Time. * strlen: (libc)String Length. * strncasecmp: (libc)String/Array Comparison. * strncat: (libc)Truncating Strings. * strncmp: (libc)String/Array Comparison. * strncpy: (libc)Truncating Strings. * strndup: (libc)Truncating Strings. * strndupa: (libc)Truncating Strings. * strnlen: (libc)String Length. * strpbrk: (libc)Search Functions. * strptime: (libc)Low-Level Time String Parsing. * strrchr: (libc)Search Functions. * strsep: (libc)Finding Tokens in a String. * strsignal: (libc)Signal Messages. * strspn: (libc)Search Functions. * strstr: (libc)Search Functions. * strtod: (libc)Parsing of Floats. * strtof: (libc)Parsing of Floats. * strtofN: (libc)Parsing of Floats. * strtofNx: (libc)Parsing of Floats. * strtoimax: (libc)Parsing of Integers. * strtok: (libc)Finding Tokens in a String. * strtok_r: (libc)Finding Tokens in a String. * strtol: (libc)Parsing of Integers. * strtold: (libc)Parsing of Floats. * strtoll: (libc)Parsing of Integers. * strtoq: (libc)Parsing of Integers. * strtoul: (libc)Parsing of Integers. * strtoull: (libc)Parsing of Integers. * strtoumax: (libc)Parsing of Integers. * strtouq: (libc)Parsing of Integers. * strverscmp: (libc)String/Array Comparison. * strxfrm: (libc)Collation Functions. * stty: (libc)BSD Terminal Modes. * swapcontext: (libc)System V contexts. * swprintf: (libc)Formatted Output Functions. * swscanf: (libc)Formatted Input Functions. * symlink: (libc)Symbolic Links. * sync: (libc)Synchronizing I/O. * syscall: (libc)System Calls. * sysconf: (libc)Sysconf Definition. * sysctl: (libc)System Parameters. * syslog: (libc)syslog; vsyslog. * system: (libc)Running a Command. * sysv_signal: (libc)Basic Signal Handling. * tan: (libc)Trig Functions. * tanf: (libc)Trig Functions. * tanfN: (libc)Trig Functions. * tanfNx: (libc)Trig Functions. * tanh: (libc)Hyperbolic Functions. * tanhf: (libc)Hyperbolic Functions. * tanhfN: (libc)Hyperbolic Functions. * tanhfNx: (libc)Hyperbolic Functions. * tanhl: (libc)Hyperbolic Functions. * tanl: (libc)Trig Functions. * tcdrain: (libc)Line Control. * tcflow: (libc)Line Control. * tcflush: (libc)Line Control. * tcgetattr: (libc)Mode Functions. * tcgetpgrp: (libc)Terminal Access Functions. * tcgetsid: (libc)Terminal Access Functions. * tcsendbreak: (libc)Line Control. * tcsetattr: (libc)Mode Functions. * tcsetpgrp: (libc)Terminal Access Functions. * tdelete: (libc)Tree Search Function. * tdestroy: (libc)Tree Search Function. * telldir: (libc)Random Access Directory. * tempnam: (libc)Temporary Files. * textdomain: (libc)Locating gettext catalog. * tfind: (libc)Tree Search Function. * tgamma: (libc)Special Functions. * tgammaf: (libc)Special Functions. * tgammafN: (libc)Special Functions. * tgammafNx: (libc)Special Functions. * tgammal: (libc)Special Functions. * thrd_create: (libc)ISO C Thread Management. * thrd_current: (libc)ISO C Thread Management. * thrd_detach: (libc)ISO C Thread Management. * thrd_equal: (libc)ISO C Thread Management. * thrd_exit: (libc)ISO C Thread Management. * thrd_join: (libc)ISO C Thread Management. * thrd_sleep: (libc)ISO C Thread Management. * thrd_yield: (libc)ISO C Thread Management. * time: (libc)Simple Calendar Time. * timegm: (libc)Broken-down Time. * timelocal: (libc)Broken-down Time. * times: (libc)Processor Time. * tmpfile64: (libc)Temporary Files. * tmpfile: (libc)Temporary Files. * tmpnam: (libc)Temporary Files. * tmpnam_r: (libc)Temporary Files. * toascii: (libc)Case Conversion. * tolower: (libc)Case Conversion. * totalorder: (libc)FP Comparison Functions. * totalorderf: (libc)FP Comparison Functions. * totalorderfN: (libc)FP Comparison Functions. * totalorderfNx: (libc)FP Comparison Functions. * totalorderl: (libc)FP Comparison Functions. * totalordermag: (libc)FP Comparison Functions. * totalordermagf: (libc)FP Comparison Functions. * totalordermagfN: (libc)FP Comparison Functions. * totalordermagfNx: (libc)FP Comparison Functions. * totalordermagl: (libc)FP Comparison Functions. * toupper: (libc)Case Conversion. * towctrans: (libc)Wide Character Case Conversion. * towlower: (libc)Wide Character Case Conversion. * towupper: (libc)Wide Character Case Conversion. * trunc: (libc)Rounding Functions. * truncate64: (libc)File Size. * truncate: (libc)File Size. * truncf: (libc)Rounding Functions. * truncfN: (libc)Rounding Functions. * truncfNx: (libc)Rounding Functions. * truncl: (libc)Rounding Functions. * tsearch: (libc)Tree Search Function. * tss_create: (libc)ISO C Thread-local Storage. * tss_delete: (libc)ISO C Thread-local Storage. * tss_get: (libc)ISO C Thread-local Storage. * tss_set: (libc)ISO C Thread-local Storage. * ttyname: (libc)Is It a Terminal. * ttyname_r: (libc)Is It a Terminal. * twalk: (libc)Tree Search Function. * tzset: (libc)Time Zone Functions. * ufromfp: (libc)Rounding Functions. * ufromfpf: (libc)Rounding Functions. * ufromfpfN: (libc)Rounding Functions. * ufromfpfNx: (libc)Rounding Functions. * ufromfpl: (libc)Rounding Functions. * ufromfpx: (libc)Rounding Functions. * ufromfpxf: (libc)Rounding Functions. * ufromfpxfN: (libc)Rounding Functions. * ufromfpxfNx: (libc)Rounding Functions. * ufromfpxl: (libc)Rounding Functions. * ulimit: (libc)Limits on Resources. * umask: (libc)Setting Permissions. * umount2: (libc)Mount-Unmount-Remount. * umount: (libc)Mount-Unmount-Remount. * uname: (libc)Platform Type. * ungetc: (libc)How Unread. * ungetwc: (libc)How Unread. * unlink: (libc)Deleting Files. * unlockpt: (libc)Allocation. * unsetenv: (libc)Environment Access. * updwtmp: (libc)Manipulating the Database. * utime: (libc)File Times. * utimes: (libc)File Times. * utmpname: (libc)Manipulating the Database. * utmpxname: (libc)XPG Functions. * va_arg: (libc)Argument Macros. * va_copy: (libc)Argument Macros. * va_end: (libc)Argument Macros. * va_start: (libc)Argument Macros. * valloc: (libc)Aligned Memory Blocks. * vasprintf: (libc)Variable Arguments Output. * verr: (libc)Error Messages. * verrx: (libc)Error Messages. * versionsort64: (libc)Scanning Directory Content. * versionsort: (libc)Scanning Directory Content. * vfork: (libc)Creating a Process. * vfprintf: (libc)Variable Arguments Output. * vfscanf: (libc)Variable Arguments Input. * vfwprintf: (libc)Variable Arguments Output. * vfwscanf: (libc)Variable Arguments Input. * vlimit: (libc)Limits on Resources. * vprintf: (libc)Variable Arguments Output. * vscanf: (libc)Variable Arguments Input. * vsnprintf: (libc)Variable Arguments Output. * vsprintf: (libc)Variable Arguments Output. * vsscanf: (libc)Variable Arguments Input. * vswprintf: (libc)Variable Arguments Output. * vswscanf: (libc)Variable Arguments Input. * vsyslog: (libc)syslog; vsyslog. * vtimes: (libc)Resource Usage. * vwarn: (libc)Error Messages. * vwarnx: (libc)Error Messages. * vwprintf: (libc)Variable Arguments Output. * vwscanf: (libc)Variable Arguments Input. * wait3: (libc)BSD Wait Functions. * wait4: (libc)Process Completion. * wait: (libc)Process Completion. * waitpid: (libc)Process Completion. * warn: (libc)Error Messages. * warnx: (libc)Error Messages. * wcpcpy: (libc)Copying Strings and Arrays. * wcpncpy: (libc)Truncating Strings. * wcrtomb: (libc)Converting a Character. * wcscasecmp: (libc)String/Array Comparison. * wcscat: (libc)Concatenating Strings. * wcschr: (libc)Search Functions. * wcschrnul: (libc)Search Functions. * wcscmp: (libc)String/Array Comparison. * wcscoll: (libc)Collation Functions. * wcscpy: (libc)Copying Strings and Arrays. * wcscspn: (libc)Search Functions. * wcsdup: (libc)Copying Strings and Arrays. * wcsftime: (libc)Formatting Calendar Time. * wcslen: (libc)String Length. * wcsncasecmp: (libc)String/Array Comparison. * wcsncat: (libc)Truncating Strings. * wcsncmp: (libc)String/Array Comparison. * wcsncpy: (libc)Truncating Strings. * wcsnlen: (libc)String Length. * wcsnrtombs: (libc)Converting Strings. * wcspbrk: (libc)Search Functions. * wcsrchr: (libc)Search Functions. * wcsrtombs: (libc)Converting Strings. * wcsspn: (libc)Search Functions. * wcsstr: (libc)Search Functions. * wcstod: (libc)Parsing of Floats. * wcstof: (libc)Parsing of Floats. * wcstofN: (libc)Parsing of Floats. * wcstofNx: (libc)Parsing of Floats. * wcstoimax: (libc)Parsing of Integers. * wcstok: (libc)Finding Tokens in a String. * wcstol: (libc)Parsing of Integers. * wcstold: (libc)Parsing of Floats. * wcstoll: (libc)Parsing of Integers. * wcstombs: (libc)Non-reentrant String Conversion. * wcstoq: (libc)Parsing of Integers. * wcstoul: (libc)Parsing of Integers. * wcstoull: (libc)Parsing of Integers. * wcstoumax: (libc)Parsing of Integers. * wcstouq: (libc)Parsing of Integers. * wcswcs: (libc)Search Functions. * wcsxfrm: (libc)Collation Functions. * wctob: (libc)Converting a Character. * wctomb: (libc)Non-reentrant Character Conversion. * wctrans: (libc)Wide Character Case Conversion. * wctype: (libc)Classification of Wide Characters. * wmemchr: (libc)Search Functions. * wmemcmp: (libc)String/Array Comparison. * wmemcpy: (libc)Copying Strings and Arrays. * wmemmove: (libc)Copying Strings and Arrays. * wmempcpy: (libc)Copying Strings and Arrays. * wmemset: (libc)Copying Strings and Arrays. * wordexp: (libc)Calling Wordexp. * wordfree: (libc)Calling Wordexp. * wprintf: (libc)Formatted Output Functions. * write: (libc)I/O Primitives. * writev: (libc)Scatter-Gather. * wscanf: (libc)Formatted Input Functions. * y0: (libc)Special Functions. * y0f: (libc)Special Functions. * y0fN: (libc)Special Functions. * y0fNx: (libc)Special Functions. * y0l: (libc)Special Functions. * y1: (libc)Special Functions. * y1f: (libc)Special Functions. * y1fN: (libc)Special Functions. * y1fNx: (libc)Special Functions. * y1l: (libc)Special Functions. * yn: (libc)Special Functions. * ynf: (libc)Special Functions. * ynfN: (libc)Special Functions. * ynfNx: (libc)Special Functions. * ynl: (libc)Special Functions. END-INFO-DIR-ENTRY  File: libc.info, Node: Output Modes, Next: Control Modes, Prev: Input Modes, Up: Terminal Modes 17.4.5 Output Modes ------------------- This section describes the terminal flags and fields that control how output characters are translated and padded for display. All of these are contained in the ‘c_oflag’ member of the ‘struct termios’ structure. The ‘c_oflag’ member itself is an integer, and you change the flags and fields using the operators ‘&’, ‘|’, and ‘^’. Don’t try to specify the entire value for ‘c_oflag’—instead, change only specific flags and leave the rest untouched (*note Setting Modes::). -- Macro: tcflag_t OPOST If this bit is set, output data is processed in some unspecified way so that it is displayed appropriately on the terminal device. This typically includes mapping newline characters (‘'\n'’) onto carriage return and linefeed pairs. If this bit isn’t set, the characters are transmitted as-is. The following three bits are effective only if ‘OPOST’ is set. -- Macro: tcflag_t ONLCR If this bit is set, convert the newline character on output into a pair of characters, carriage return followed by linefeed. -- Macro: tcflag_t OXTABS If this bit is set, convert tab characters on output into the appropriate number of spaces to emulate a tab stop every eight columns. This bit exists only on BSD systems and GNU/Hurd systems; on GNU/Linux systems it is available as ‘XTABS’. -- Macro: tcflag_t ONOEOT If this bit is set, discard ‘C-d’ characters (code ‘004’) on output. These characters cause many dial-up terminals to disconnect. This bit exists only on BSD systems and GNU/Hurd systems.  File: libc.info, Node: Control Modes, Next: Local Modes, Prev: Output Modes, Up: Terminal Modes 17.4.6 Control Modes -------------------- This section describes the terminal flags and fields that control parameters usually associated with asynchronous serial data transmission. These flags may not make sense for other kinds of terminal ports (such as a network connection pseudo-terminal). All of these are contained in the ‘c_cflag’ member of the ‘struct termios’ structure. The ‘c_cflag’ member itself is an integer, and you change the flags and fields using the operators ‘&’, ‘|’, and ‘^’. Don’t try to specify the entire value for ‘c_cflag’—instead, change only specific flags and leave the rest untouched (*note Setting Modes::). -- Macro: tcflag_t CLOCAL If this bit is set, it indicates that the terminal is connected “locally” and that the modem status lines (such as carrier detect) should be ignored. On many systems if this bit is not set and you call ‘open’ without the ‘O_NONBLOCK’ flag set, ‘open’ blocks until a modem connection is established. If this bit is not set and a modem disconnect is detected, a ‘SIGHUP’ signal is sent to the controlling process group for the terminal (if it has one). Normally, this causes the process to exit; see *note Signal Handling::. Reading from the terminal after a disconnect causes an end-of-file condition, and writing causes an ‘EIO’ error to be returned. The terminal device must be closed and reopened to clear the condition. -- Macro: tcflag_t HUPCL If this bit is set, a modem disconnect is generated when all processes that have the terminal device open have either closed the file or exited. -- Macro: tcflag_t CREAD If this bit is set, input can be read from the terminal. Otherwise, input is discarded when it arrives. -- Macro: tcflag_t CSTOPB If this bit is set, two stop bits are used. Otherwise, only one stop bit is used. -- Macro: tcflag_t PARENB If this bit is set, generation and detection of a parity bit are enabled. *Note Input Modes::, for information on how input parity errors are handled. If this bit is not set, no parity bit is added to output characters, and input characters are not checked for correct parity. -- Macro: tcflag_t PARODD This bit is only useful if ‘PARENB’ is set. If ‘PARODD’ is set, odd parity is used, otherwise even parity is used. The control mode flags also includes a field for the number of bits per character. You can use the ‘CSIZE’ macro as a mask to extract the value, like this: ‘settings.c_cflag & CSIZE’. -- Macro: tcflag_t CSIZE This is a mask for the number of bits per character. -- Macro: tcflag_t CS5 This specifies five bits per byte. -- Macro: tcflag_t CS6 This specifies six bits per byte. -- Macro: tcflag_t CS7 This specifies seven bits per byte. -- Macro: tcflag_t CS8 This specifies eight bits per byte. The following four bits are BSD extensions; these exist only on BSD systems and GNU/Hurd systems. -- Macro: tcflag_t CCTS_OFLOW If this bit is set, enable flow control of output based on the CTS wire (RS232 protocol). -- Macro: tcflag_t CRTS_IFLOW If this bit is set, enable flow control of input based on the RTS wire (RS232 protocol). -- Macro: tcflag_t MDMBUF If this bit is set, enable carrier-based flow control of output. -- Macro: tcflag_t CIGNORE If this bit is set, it says to ignore the control modes and line speed values entirely. This is only meaningful in a call to ‘tcsetattr’. The ‘c_cflag’ member and the line speed values returned by ‘cfgetispeed’ and ‘cfgetospeed’ will be unaffected by the call. ‘CIGNORE’ is useful if you want to set all the software modes in the other members, but leave the hardware details in ‘c_cflag’ unchanged. (This is how the ‘TCSASOFT’ flag to ‘tcsettattr’ works.) This bit is never set in the structure filled in by ‘tcgetattr’.  File: libc.info, Node: Local Modes, Next: Line Speed, Prev: Control Modes, Up: Terminal Modes 17.4.7 Local Modes ------------------ This section describes the flags for the ‘c_lflag’ member of the ‘struct termios’ structure. These flags generally control higher-level aspects of input processing than the input modes flags described in *note Input Modes::, such as echoing, signals, and the choice of canonical or noncanonical input. The ‘c_lflag’ member itself is an integer, and you change the flags and fields using the operators ‘&’, ‘|’, and ‘^’. Don’t try to specify the entire value for ‘c_lflag’—instead, change only specific flags and leave the rest untouched (*note Setting Modes::). -- Macro: tcflag_t ICANON This bit, if set, enables canonical input processing mode. Otherwise, input is processed in noncanonical mode. *Note Canonical or Not::. -- Macro: tcflag_t ECHO If this bit is set, echoing of input characters back to the terminal is enabled. -- Macro: tcflag_t ECHOE If this bit is set, echoing indicates erasure of input with the ERASE character by erasing the last character in the current line from the screen. Otherwise, the character erased is re-echoed to show what has happened (suitable for a printing terminal). This bit only controls the display behavior; the ‘ICANON’ bit by itself controls actual recognition of the ERASE character and erasure of input, without which ‘ECHOE’ is simply irrelevant. -- Macro: tcflag_t ECHOPRT This bit, like ‘ECHOE’, enables display of the ERASE character in a way that is geared to a hardcopy terminal. When you type the ERASE character, a ‘\’ character is printed followed by the first character erased. Typing the ERASE character again just prints the next character erased. Then, the next time you type a normal character, a ‘/’ character is printed before the character echoes. This is a BSD extension, and exists only in BSD systems and GNU/Linux and GNU/Hurd systems. -- Macro: tcflag_t ECHOK This bit enables special display of the KILL character by moving to a new line after echoing the KILL character normally. The behavior of ‘ECHOKE’ (below) is nicer to look at. If this bit is not set, the KILL character echoes just as it would if it were not the KILL character. Then it is up to the user to remember that the KILL character has erased the preceding input; there is no indication of this on the screen. This bit only controls the display behavior; the ‘ICANON’ bit by itself controls actual recognition of the KILL character and erasure of input, without which ‘ECHOK’ is simply irrelevant. -- Macro: tcflag_t ECHOKE This bit is similar to ‘ECHOK’. It enables special display of the KILL character by erasing on the screen the entire line that has been killed. This is a BSD extension, and exists only in BSD systems and GNU/Linux and GNU/Hurd systems. -- Macro: tcflag_t ECHONL If this bit is set and the ‘ICANON’ bit is also set, then the newline (‘'\n'’) character is echoed even if the ‘ECHO’ bit is not set. -- Macro: tcflag_t ECHOCTL If this bit is set and the ‘ECHO’ bit is also set, echo control characters with ‘^’ followed by the corresponding text character. Thus, control-A echoes as ‘^A’. This is usually the preferred mode for interactive input, because echoing a control character back to the terminal could have some undesired effect on the terminal. This is a BSD extension, and exists only in BSD systems and GNU/Linux and GNU/Hurd systems. -- Macro: tcflag_t ISIG This bit controls whether the INTR, QUIT, and SUSP characters are recognized. The functions associated with these characters are performed if and only if this bit is set. Being in canonical or noncanonical input mode has no effect on the interpretation of these characters. You should use caution when disabling recognition of these characters. Programs that cannot be interrupted interactively are very user-unfriendly. If you clear this bit, your program should provide some alternate interface that allows the user to interactively send the signals associated with these characters, or to escape from the program. *Note Signal Characters::. -- Macro: tcflag_t IEXTEN POSIX.1 gives ‘IEXTEN’ implementation-defined meaning, so you cannot rely on this interpretation on all systems. On BSD systems and GNU/Linux and GNU/Hurd systems, it enables the LNEXT and DISCARD characters. *Note Other Special::. -- Macro: tcflag_t NOFLSH Normally, the INTR, QUIT, and SUSP characters cause input and output queues for the terminal to be cleared. If this bit is set, the queues are not cleared. -- Macro: tcflag_t TOSTOP If this bit is set and the system supports job control, then ‘SIGTTOU’ signals are generated by background processes that attempt to write to the terminal. *Note Access to the Terminal::. The following bits are BSD extensions; they exist only on BSD systems and GNU/Hurd systems. -- Macro: tcflag_t ALTWERASE This bit determines how far the WERASE character should erase. The WERASE character erases back to the beginning of a word; the question is, where do words begin? If this bit is clear, then the beginning of a word is a nonwhitespace character following a whitespace character. If the bit is set, then the beginning of a word is an alphanumeric character or underscore following a character which is none of those. *Note Editing Characters::, for more information about the WERASE character. -- Macro: tcflag_t FLUSHO This is the bit that toggles when the user types the DISCARD character. While this bit is set, all output is discarded. *Note Other Special::. -- Macro: tcflag_t NOKERNINFO Setting this bit disables handling of the STATUS character. *Note Other Special::. -- Macro: tcflag_t PENDIN If this bit is set, it indicates that there is a line of input that needs to be reprinted. Typing the REPRINT character sets this bit; the bit remains set until reprinting is finished. *Note Editing Characters::.  File: libc.info, Node: Line Speed, Next: Special Characters, Prev: Local Modes, Up: Terminal Modes 17.4.8 Line Speed ----------------- The terminal line speed tells the computer how fast to read and write data on the terminal. If the terminal is connected to a real serial line, the terminal speed you specify actually controls the line—if it doesn’t match the terminal’s own idea of the speed, communication does not work. Real serial ports accept only certain standard speeds. Also, particular hardware may not support even all the standard speeds. Specifying a speed of zero hangs up a dialup connection and turns off modem control signals. If the terminal is not a real serial line (for example, if it is a network connection), then the line speed won’t really affect data transmission speed, but some programs will use it to determine the amount of padding needed. It’s best to specify a line speed value that matches the actual speed of the actual terminal, but you can safely experiment with different values to vary the amount of padding. There are actually two line speeds for each terminal, one for input and one for output. You can set them independently, but most often terminals use the same speed for both directions. The speed values are stored in the ‘struct termios’ structure, but don’t try to access them in the ‘struct termios’ structure directly. Instead, you should use the following functions to read and store them: -- Function: speed_t cfgetospeed (const struct termios *TERMIOS-P) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. This function returns the output line speed stored in the structure ‘*TERMIOS-P’. -- Function: speed_t cfgetispeed (const struct termios *TERMIOS-P) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. This function returns the input line speed stored in the structure ‘*TERMIOS-P’. -- Function: int cfsetospeed (struct termios *TERMIOS-P, speed_t SPEED) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. This function stores SPEED in ‘*TERMIOS-P’ as the output speed. The normal return value is 0; a value of -1 indicates an error. If SPEED is not a speed, ‘cfsetospeed’ returns -1. -- Function: int cfsetispeed (struct termios *TERMIOS-P, speed_t SPEED) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. This function stores SPEED in ‘*TERMIOS-P’ as the input speed. The normal return value is 0; a value of -1 indicates an error. If SPEED is not a speed, ‘cfsetospeed’ returns -1. -- Function: int cfsetspeed (struct termios *TERMIOS-P, speed_t SPEED) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. This function stores SPEED in ‘*TERMIOS-P’ as both the input and output speeds. The normal return value is 0; a value of -1 indicates an error. If SPEED is not a speed, ‘cfsetspeed’ returns -1. This function is an extension in 4.4 BSD. -- Data Type: speed_t The ‘speed_t’ type is an unsigned integer data type used to represent line speeds. The functions ‘cfsetospeed’ and ‘cfsetispeed’ report errors only for speed values that the system simply cannot handle. If you specify a speed value that is basically acceptable, then those functions will succeed. But they do not check that a particular hardware device can actually support the specified speeds—in fact, they don’t know which device you plan to set the speed for. If you use ‘tcsetattr’ to set the speed of a particular device to a value that it cannot handle, ‘tcsetattr’ returns -1. *Portability note:* In the GNU C Library, the functions above accept speeds measured in bits per second as input, and return speed values measured in bits per second. Other libraries require speeds to be indicated by special codes. For POSIX.1 portability, you must use one of the following symbols to represent the speed; their precise numeric values are system-dependent, but each name has a fixed meaning: ‘B110’ stands for 110 bps, ‘B300’ for 300 bps, and so on. There is no portable way to represent any speed but these, but these are the only speeds that typical serial lines can support. B0 B50 B75 B110 B134 B150 B200 B300 B600 B1200 B1800 B2400 B4800 B9600 B19200 B38400 B57600 B115200 B230400 B460800 BSD defines two additional speed symbols as aliases: ‘EXTA’ is an alias for ‘B19200’ and ‘EXTB’ is an alias for ‘B38400’. These aliases are obsolete.  File: libc.info, Node: Special Characters, Next: Noncanonical Input, Prev: Line Speed, Up: Terminal Modes 17.4.9 Special Characters ------------------------- In canonical input, the terminal driver recognizes a number of special characters which perform various control functions. These include the ERASE character (usually ) for editing input, and other editing characters. The INTR character (normally ‘C-c’) for sending a ‘SIGINT’ signal, and other signal-raising characters, may be available in either canonical or noncanonical input mode. All these characters are described in this section. The particular characters used are specified in the ‘c_cc’ member of the ‘struct termios’ structure. This member is an array; each element specifies the character for a particular role. Each element has a symbolic constant that stands for the index of that element—for example, ‘VINTR’ is the index of the element that specifies the INTR character, so storing ‘'='’ in ‘TERMIOS.c_cc[VINTR]’ specifies ‘=’ as the INTR character. On some systems, you can disable a particular special character function by specifying the value ‘_POSIX_VDISABLE’ for that role. This value is unequal to any possible character code. *Note Options for Files::, for more information about how to tell whether the operating system you are using supports ‘_POSIX_VDISABLE’. * Menu: * Editing Characters:: Special characters that terminate lines and delete text, and other editing functions. * Signal Characters:: Special characters that send or raise signals to or for certain classes of processes. * Start/Stop Characters:: Special characters that suspend or resume suspended output. * Other Special:: Other special characters for BSD systems: they can discard output, and print status.  File: libc.info, Node: Editing Characters, Next: Signal Characters, Up: Special Characters 17.4.9.1 Characters for Input Editing ..................................... These special characters are active only in canonical input mode. *Note Canonical or Not::. -- Macro: int VEOF This is the subscript for the EOF character in the special control character array. ‘TERMIOS.c_cc[VEOF]’ holds the character itself. The EOF character is recognized only in canonical input mode. It acts as a line terminator in the same way as a newline character, but if the EOF character is typed at the beginning of a line it causes ‘read’ to return a byte count of zero, indicating end-of-file. The EOF character itself is discarded. Usually, the EOF character is ‘C-d’. -- Macro: int VEOL This is the subscript for the EOL character in the special control character array. ‘TERMIOS.c_cc[VEOL]’ holds the character itself. The EOL character is recognized only in canonical input mode. It acts as a line terminator, just like a newline character. The EOL character is not discarded; it is read as the last character in the input line. You don’t need to use the EOL character to make end a line. Just set the ICRNL flag. In fact, this is the default state of affairs. -- Macro: int VEOL2 This is the subscript for the EOL2 character in the special control character array. ‘TERMIOS.c_cc[VEOL2]’ holds the character itself. The EOL2 character works just like the EOL character (see above), but it can be a different character. Thus, you can specify two characters to terminate an input line, by setting EOL to one of them and EOL2 to the other. The EOL2 character is a BSD extension; it exists only on BSD systems and GNU/Linux and GNU/Hurd systems. -- Macro: int VERASE This is the subscript for the ERASE character in the special control character array. ‘TERMIOS.c_cc[VERASE]’ holds the character itself. The ERASE character is recognized only in canonical input mode. When the user types the erase character, the previous character typed is discarded. (If the terminal generates multibyte character sequences, this may cause more than one byte of input to be discarded.) This cannot be used to erase past the beginning of the current line of text. The ERASE character itself is discarded. Usually, the ERASE character is . -- Macro: int VWERASE This is the subscript for the WERASE character in the special control character array. ‘TERMIOS.c_cc[VWERASE]’ holds the character itself. The WERASE character is recognized only in canonical mode. It erases an entire word of prior input, and any whitespace after it; whitespace characters before the word are not erased. The definition of a “word” depends on the setting of the ‘ALTWERASE’ mode; *note Local Modes::. If the ‘ALTWERASE’ mode is not set, a word is defined as a sequence of any characters except space or tab. If the ‘ALTWERASE’ mode is set, a word is defined as a sequence of characters containing only letters, numbers, and underscores, optionally followed by one character that is not a letter, number, or underscore. The WERASE character is usually ‘C-w’. This is a BSD extension. -- Macro: int VKILL This is the subscript for the KILL character in the special control character array. ‘TERMIOS.c_cc[VKILL]’ holds the character itself. The KILL character is recognized only in canonical input mode. When the user types the kill character, the entire contents of the current line of input are discarded. The kill character itself is discarded too. The KILL character is usually ‘C-u’. -- Macro: int VREPRINT This is the subscript for the REPRINT character in the special control character array. ‘TERMIOS.c_cc[VREPRINT]’ holds the character itself. The REPRINT character is recognized only in canonical mode. It reprints the current input line. If some asynchronous output has come while you are typing, this lets you see the line you are typing clearly again. The REPRINT character is usually ‘C-r’. This is a BSD extension.  File: libc.info, Node: Signal Characters, Next: Start/Stop Characters, Prev: Editing Characters, Up: Special Characters 17.4.9.2 Characters that Cause Signals ...................................... These special characters may be active in either canonical or noncanonical input mode, but only when the ‘ISIG’ flag is set (*note Local Modes::). -- Macro: int VINTR This is the subscript for the INTR character in the special control character array. ‘TERMIOS.c_cc[VINTR]’ holds the character itself. The INTR (interrupt) character raises a ‘SIGINT’ signal for all processes in the foreground job associated with the terminal. The INTR character itself is then discarded. *Note Signal Handling::, for more information about signals. Typically, the INTR character is ‘C-c’. -- Macro: int VQUIT This is the subscript for the QUIT character in the special control character array. ‘TERMIOS.c_cc[VQUIT]’ holds the character itself. The QUIT character raises a ‘SIGQUIT’ signal for all processes in the foreground job associated with the terminal. The QUIT character itself is then discarded. *Note Signal Handling::, for more information about signals. Typically, the QUIT character is ‘C-\’. -- Macro: int VSUSP This is the subscript for the SUSP character in the special control character array. ‘TERMIOS.c_cc[VSUSP]’ holds the character itself. The SUSP (suspend) character is recognized only if the implementation supports job control (*note Job Control::). It causes a ‘SIGTSTP’ signal to be sent to all processes in the foreground job associated with the terminal. The SUSP character itself is then discarded. *Note Signal Handling::, for more information about signals. Typically, the SUSP character is ‘C-z’. Few applications disable the normal interpretation of the SUSP character. If your program does this, it should provide some other mechanism for the user to stop the job. When the user invokes this mechanism, the program should send a ‘SIGTSTP’ signal to the process group of the process, not just to the process itself. *Note Signaling Another Process::. -- Macro: int VDSUSP This is the subscript for the DSUSP character in the special control character array. ‘TERMIOS.c_cc[VDSUSP]’ holds the character itself. The DSUSP (suspend) character is recognized only if the implementation supports job control (*note Job Control::). It sends a ‘SIGTSTP’ signal, like the SUSP character, but not right away—only when the program tries to read it as input. Not all systems with job control support DSUSP; only BSD-compatible systems do (including GNU/Hurd systems). *Note Signal Handling::, for more information about signals. Typically, the DSUSP character is ‘C-y’.  File: libc.info, Node: Start/Stop Characters, Next: Other Special, Prev: Signal Characters, Up: Special Characters 17.4.9.3 Special Characters for Flow Control ............................................ These special characters may be active in either canonical or noncanonical input mode, but their use is controlled by the flags ‘IXON’ and ‘IXOFF’ (*note Input Modes::). -- Macro: int VSTART This is the subscript for the START character in the special control character array. ‘TERMIOS.c_cc[VSTART]’ holds the character itself. The START character is used to support the ‘IXON’ and ‘IXOFF’ input modes. If ‘IXON’ is set, receiving a START character resumes suspended output; the START character itself is discarded. If ‘IXANY’ is set, receiving any character at all resumes suspended output; the resuming character is not discarded unless it is the START character. If ‘IXOFF’ is set, the system may also transmit START characters to the terminal. The usual value for the START character is ‘C-q’. You may not be able to change this value—the hardware may insist on using ‘C-q’ regardless of what you specify. -- Macro: int VSTOP This is the subscript for the STOP character in the special control character array. ‘TERMIOS.c_cc[VSTOP]’ holds the character itself. The STOP character is used to support the ‘IXON’ and ‘IXOFF’ input modes. If ‘IXON’ is set, receiving a STOP character causes output to be suspended; the STOP character itself is discarded. If ‘IXOFF’ is set, the system may also transmit STOP characters to the terminal, to prevent the input queue from overflowing. The usual value for the STOP character is ‘C-s’. You may not be able to change this value—the hardware may insist on using ‘C-s’ regardless of what you specify.  File: libc.info, Node: Other Special, Prev: Start/Stop Characters, Up: Special Characters 17.4.9.4 Other Special Characters ................................. -- Macro: int VLNEXT This is the subscript for the LNEXT character in the special control character array. ‘TERMIOS.c_cc[VLNEXT]’ holds the character itself. The LNEXT character is recognized only when ‘IEXTEN’ is set, but in both canonical and noncanonical mode. It disables any special significance of the next character the user types. Even if the character would normally perform some editing function or generate a signal, it is read as a plain character. This is the analogue of the ‘C-q’ command in Emacs. “LNEXT” stands for “literal next.” The LNEXT character is usually ‘C-v’. This character is available on BSD systems and GNU/Linux and GNU/Hurd systems. -- Macro: int VDISCARD This is the subscript for the DISCARD character in the special control character array. ‘TERMIOS.c_cc[VDISCARD]’ holds the character itself. The DISCARD character is recognized only when ‘IEXTEN’ is set, but in both canonical and noncanonical mode. Its effect is to toggle the discard-output flag. When this flag is set, all program output is discarded. Setting the flag also discards all output currently in the output buffer. Typing any other character resets the flag. This character is available on BSD systems and GNU/Linux and GNU/Hurd systems. -- Macro: int VSTATUS This is the subscript for the STATUS character in the special control character array. ‘TERMIOS.c_cc[VSTATUS]’ holds the character itself. The STATUS character’s effect is to print out a status message about how the current process is running. The STATUS character is recognized only in canonical mode, and only if ‘NOKERNINFO’ is not set. This character is available only on BSD systems and GNU/Hurd systems.  File: libc.info, Node: Noncanonical Input, Prev: Special Characters, Up: Terminal Modes 17.4.10 Noncanonical Input -------------------------- In noncanonical input mode, the special editing characters such as ERASE and KILL are ignored. The system facilities for the user to edit input are disabled in noncanonical mode, so that all input characters (unless they are special for signal or flow-control purposes) are passed to the application program exactly as typed. It is up to the application program to give the user ways to edit the input, if appropriate. Noncanonical mode offers special parameters called MIN and TIME for controlling whether and how long to wait for input to be available. You can even use them to avoid ever waiting—to return immediately with whatever input is available, or with no input. The MIN and TIME are stored in elements of the ‘c_cc’ array, which is a member of the ‘struct termios’ structure. Each element of this array has a particular role, and each element has a symbolic constant that stands for the index of that element. ‘VMIN’ and ‘VTIME’ are the names for the indices in the array of the MIN and TIME slots. -- Macro: int VMIN This is the subscript for the MIN slot in the ‘c_cc’ array. Thus, ‘TERMIOS.c_cc[VMIN]’ is the value itself. The MIN slot is only meaningful in noncanonical input mode; it specifies the minimum number of bytes that must be available in the input queue in order for ‘read’ to return. -- Macro: int VTIME This is the subscript for the TIME slot in the ‘c_cc’ array. Thus, ‘TERMIOS.c_cc[VTIME]’ is the value itself. The TIME slot is only meaningful in noncanonical input mode; it specifies how long to wait for input before returning, in units of 0.1 seconds. The MIN and TIME values interact to determine the criterion for when ‘read’ should return; their precise meanings depend on which of them are nonzero. There are four possible cases: • Both TIME and MIN are nonzero. In this case, TIME specifies how long to wait after each input character to see if more input arrives. After the first character received, ‘read’ keeps waiting until either MIN bytes have arrived in all, or TIME elapses with no further input. ‘read’ always blocks until the first character arrives, even if TIME elapses first. ‘read’ can return more than MIN characters if more than MIN happen to be in the queue. • Both MIN and TIME are zero. In this case, ‘read’ always returns immediately with as many characters as are available in the queue, up to the number requested. If no input is immediately available, ‘read’ returns a value of zero. • MIN is zero but TIME has a nonzero value. In this case, ‘read’ waits for time TIME for input to become available; the availability of a single byte is enough to satisfy the read request and cause ‘read’ to return. When it returns, it returns as many characters as are available, up to the number requested. If no input is available before the timer expires, ‘read’ returns a value of zero. • TIME is zero but MIN has a nonzero value. In this case, ‘read’ waits until at least MIN bytes are available in the queue. At that time, ‘read’ returns as many characters as are available, up to the number requested. ‘read’ can return more than MIN characters if more than MIN happen to be in the queue. What happens if MIN is 50 and you ask to read just 10 bytes? Normally, ‘read’ waits until there are 50 bytes in the buffer (or, more generally, the wait condition described above is satisfied), and then reads 10 of them, leaving the other 40 buffered in the operating system for a subsequent call to ‘read’. *Portability note:* On some systems, the MIN and TIME slots are actually the same as the EOF and EOL slots. This causes no serious problem because the MIN and TIME slots are used only in noncanonical input and the EOF and EOL slots are used only in canonical input, but it isn’t very clean. The GNU C Library allocates separate slots for these uses. -- Function: void cfmakeraw (struct termios *TERMIOS-P) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. This function provides an easy way to set up ‘*TERMIOS-P’ for what has traditionally been called “raw mode” in BSD. This uses noncanonical input, and turns off most processing to give an unmodified channel to the terminal. It does exactly this: TERMIOS-P->c_iflag &= ~(IGNBRK|BRKINT|PARMRK|ISTRIP |INLCR|IGNCR|ICRNL|IXON); TERMIOS-P->c_oflag &= ~OPOST; TERMIOS-P->c_lflag &= ~(ECHO|ECHONL|ICANON|ISIG|IEXTEN); TERMIOS-P->c_cflag &= ~(CSIZE|PARENB); TERMIOS-P->c_cflag |= CS8;  File: libc.info, Node: BSD Terminal Modes, Next: Line Control, Prev: Terminal Modes, Up: Low-Level Terminal Interface 17.5 BSD Terminal Modes ======================= The usual way to get and set terminal modes is with the functions described in *note Terminal Modes::. However, on some systems you can use the BSD-derived functions in this section to do some of the same things. On many systems, these functions do not exist. Even with the GNU C Library, the functions simply fail with ‘errno’ = ‘ENOSYS’ with many kernels, including Linux. The symbols used in this section are declared in ‘sgtty.h’. -- Data Type: struct sgttyb This structure is an input or output parameter list for ‘gtty’ and ‘stty’. ‘char sg_ispeed’ Line speed for input ‘char sg_ospeed’ Line speed for output ‘char sg_erase’ Erase character ‘char sg_kill’ Kill character ‘int sg_flags’ Various flags -- Function: int gtty (int FILEDES, struct sgttyb *ATTRIBUTES) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. This function gets the attributes of a terminal. ‘gtty’ sets *ATTRIBUTES to describe the terminal attributes of the terminal which is open with file descriptor FILEDES. -- Function: int stty (int FILEDES, const struct sgttyb *ATTRIBUTES) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. This function sets the attributes of a terminal. ‘stty’ sets the terminal attributes of the terminal which is open with file descriptor FILEDES to those described by *ATTRIBUTES.  File: libc.info, Node: Line Control, Next: Noncanon Example, Prev: BSD Terminal Modes, Up: Low-Level Terminal Interface 17.6 Line Control Functions =========================== These functions perform miscellaneous control actions on terminal devices. As regards terminal access, they are treated like doing output: if any of these functions is used by a background process on its controlling terminal, normally all processes in the process group are sent a ‘SIGTTOU’ signal. The exception is if the calling process itself is ignoring or blocking ‘SIGTTOU’ signals, in which case the operation is performed and no signal is sent. *Note Job Control::. -- Function: int tcsendbreak (int FILEDES, int DURATION) Preliminary: | MT-Unsafe race:tcattr(filedes)/bsd | AS-Unsafe | AC-Unsafe corrupt/bsd | *Note POSIX Safety Concepts::. This function generates a break condition by transmitting a stream of zero bits on the terminal associated with the file descriptor FILEDES. The duration of the break is controlled by the DURATION argument. If zero, the duration is between 0.25 and 0.5 seconds. The meaning of a nonzero value depends on the operating system. This function does nothing if the terminal is not an asynchronous serial data port. The return value is normally zero. In the event of an error, a value of -1 is returned. The following ‘errno’ error conditions are defined for this function: ‘EBADF’ The FILEDES is not a valid file descriptor. ‘ENOTTY’ The FILEDES is not associated with a terminal device. -- Function: int tcdrain (int FILEDES) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. The ‘tcdrain’ function waits until all queued output to the terminal FILEDES has been transmitted. This function is a cancellation point in multi-threaded programs. This is a problem if the thread allocates some resources (like memory, file descriptors, semaphores or whatever) at the time ‘tcdrain’ is called. If the thread gets canceled these resources stay allocated until the program ends. To avoid this calls to ‘tcdrain’ should be protected using cancellation handlers. The return value is normally zero. In the event of an error, a value of -1 is returned. The following ‘errno’ error conditions are defined for this function: ‘EBADF’ The FILEDES is not a valid file descriptor. ‘ENOTTY’ The FILEDES is not associated with a terminal device. ‘EINTR’ The operation was interrupted by delivery of a signal. *Note Interrupted Primitives::. -- Function: int tcflush (int FILEDES, int QUEUE) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. The ‘tcflush’ function is used to clear the input and/or output queues associated with the terminal file FILEDES. The QUEUE argument specifies which queue(s) to clear, and can be one of the following values: ‘TCIFLUSH’ Clear any input data received, but not yet read. ‘TCOFLUSH’ Clear any output data written, but not yet transmitted. ‘TCIOFLUSH’ Clear both queued input and output. The return value is normally zero. In the event of an error, a value of -1 is returned. The following ‘errno’ error conditions are defined for this function: ‘EBADF’ The FILEDES is not a valid file descriptor. ‘ENOTTY’ The FILEDES is not associated with a terminal device. ‘EINVAL’ A bad value was supplied as the QUEUE argument. It is unfortunate that this function is named ‘tcflush’, because the term “flush” is normally used for quite another operation—waiting until all output is transmitted—and using it for discarding input or output would be confusing. Unfortunately, the name ‘tcflush’ comes from POSIX and we cannot change it. -- Function: int tcflow (int FILEDES, int ACTION) Preliminary: | MT-Unsafe race:tcattr(filedes)/bsd | AS-Unsafe | AC-Safe | *Note POSIX Safety Concepts::. The ‘tcflow’ function is used to perform operations relating to XON/XOFF flow control on the terminal file specified by FILEDES. The ACTION argument specifies what operation to perform, and can be one of the following values: ‘TCOOFF’ Suspend transmission of output. ‘TCOON’ Restart transmission of output. ‘TCIOFF’ Transmit a STOP character. ‘TCION’ Transmit a START character. For more information about the STOP and START characters, see *note Special Characters::. The return value is normally zero. In the event of an error, a value of -1 is returned. The following ‘errno’ error conditions are defined for this function: ‘EBADF’ The FILEDES is not a valid file descriptor. ‘ENOTTY’ The FILEDES is not associated with a terminal device. ‘EINVAL’ A bad value was supplied as the ACTION argument.  File: libc.info, Node: Noncanon Example, Next: getpass, Prev: Line Control, Up: Low-Level Terminal Interface 17.7 Noncanonical Mode Example ============================== Here is an example program that shows how you can set up a terminal device to read single characters in noncanonical input mode, without echo. #include #include #include #include /* Use this variable to remember original terminal attributes. */ struct termios saved_attributes; void reset_input_mode (void) { tcsetattr (STDIN_FILENO, TCSANOW, &saved_attributes); } void set_input_mode (void) { struct termios tattr; char *name; /* Make sure stdin is a terminal. */ if (!isatty (STDIN_FILENO)) { fprintf (stderr, "Not a terminal.\n"); exit (EXIT_FAILURE); } /* Save the terminal attributes so we can restore them later. */ tcgetattr (STDIN_FILENO, &saved_attributes); atexit (reset_input_mode); /* Set the funny terminal modes. */ tcgetattr (STDIN_FILENO, &tattr); tattr.c_lflag &= ~(ICANON|ECHO); /* Clear ICANON and ECHO. */ tattr.c_cc[VMIN] = 1; tattr.c_cc[VTIME] = 0; tcsetattr (STDIN_FILENO, TCSAFLUSH, &tattr); } int main (void) { char c; set_input_mode (); while (1) { read (STDIN_FILENO, &c, 1); if (c == '\004') /* ‘C-d’ */ break; else putchar (c); } return EXIT_SUCCESS; } This program is careful to restore the original terminal modes before exiting or terminating with a signal. It uses the ‘atexit’ function (*note Cleanups on Exit::) to make sure this is done by ‘exit’. The shell is supposed to take care of resetting the terminal modes when a process is stopped or continued; see *note Job Control::. But some existing shells do not actually do this, so you may wish to establish handlers for job control signals that reset terminal modes. The above example does so.  File: libc.info, Node: getpass, Next: Pseudo-Terminals, Prev: Noncanon Example, Up: Low-Level Terminal Interface 17.8 Reading Passphrases ======================== When reading in a passphrase, it is desirable to avoid displaying it on the screen, to help keep it secret. The following function handles this in a convenient way. -- Function: char * getpass (const char *PROMPT) Preliminary: | MT-Unsafe term | AS-Unsafe heap lock corrupt | AC-Unsafe term lock corrupt | *Note POSIX Safety Concepts::. ‘getpass’ outputs PROMPT, then reads a string in from the terminal without echoing it. It tries to connect to the real terminal, ‘/dev/tty’, if possible, to encourage users not to put plaintext passphrases in files; otherwise, it uses ‘stdin’ and ‘stderr’. ‘getpass’ also disables the INTR, QUIT, and SUSP characters on the terminal using the ‘ISIG’ terminal attribute (*note Local Modes::). The terminal is flushed before and after ‘getpass’, so that characters of a mistyped passphrase are not accidentally visible. In other C libraries, ‘getpass’ may only return the first ‘PASS_MAX’ bytes of a passphrase. The GNU C Library has no limit, so ‘PASS_MAX’ is undefined. The prototype for this function is in ‘unistd.h’. ‘PASS_MAX’ would be defined in ‘limits.h’. This precise set of operations may not suit all possible situations. In this case, it is recommended that users write their own ‘getpass’ substitute. For instance, a very simple substitute is as follows: #include #include ssize_t my_getpass (char **lineptr, size_t *n, FILE *stream) { struct termios old, new; int nread; /* Turn echoing off and fail if we can’t. */ if (tcgetattr (fileno (stream), &old) != 0) return -1; new = old; new.c_lflag &= ~ECHO; if (tcsetattr (fileno (stream), TCSAFLUSH, &new) != 0) return -1; /* Read the passphrase */ nread = getline (lineptr, n, stream); /* Restore terminal. */ (void) tcsetattr (fileno (stream), TCSAFLUSH, &old); return nread; } The substitute takes the same parameters as ‘getline’ (*note Line Input::); the user must print any prompt desired.  File: libc.info, Node: Pseudo-Terminals, Prev: getpass, Up: Low-Level Terminal Interface 17.9 Pseudo-Terminals ===================== A “pseudo-terminal” is a special interprocess communication channel that acts like a terminal. One end of the channel is called the “master” side or “master pseudo-terminal device”, the other side is called the “slave” side. Data written to the master side is received by the slave side as if it was the result of a user typing at an ordinary terminal, and data written to the slave side is sent to the master side as if it was written on an ordinary terminal. Pseudo terminals are the way programs like ‘xterm’ and ‘emacs’ implement their terminal emulation functionality. * Menu: * Allocation:: Allocating a pseudo terminal. * Pseudo-Terminal Pairs:: How to open both sides of a pseudo-terminal in a single operation.  File: libc.info, Node: Allocation, Next: Pseudo-Terminal Pairs, Up: Pseudo-Terminals 17.9.1 Allocating Pseudo-Terminals ---------------------------------- This subsection describes functions for allocating a pseudo-terminal, and for making this pseudo-terminal available for actual use. These functions are declared in the header file ‘stdlib.h’. -- Function: int getpt (void) Preliminary: | MT-Safe | AS-Safe | AC-Safe fd | *Note POSIX Safety Concepts::. The ‘getpt’ function returns a new file descriptor for the next available master pseudo-terminal. The normal return value from ‘getpt’ is a non-negative integer file descriptor. In the case of an error, a value of -1 is returned instead. The following ‘errno’ conditions are defined for this function: ‘ENOENT’ There are no free master pseudo-terminals available. This function is a GNU extension. -- Function: int grantpt (int FILEDES) Preliminary: | MT-Safe locale | AS-Unsafe dlopen plugin heap lock | AC-Unsafe corrupt lock fd mem | *Note POSIX Safety Concepts::. The ‘grantpt’ function changes the ownership and access permission of the slave pseudo-terminal device corresponding to the master pseudo-terminal device associated with the file descriptor FILEDES. The owner is set from the real user ID of the calling process (*note Process Persona::), and the group is set to a special group (typically “tty”) or from the real group ID of the calling process. The access permission is set such that the file is both readable and writable by the owner and only writable by the group. On some systems this function is implemented by invoking a special ‘setuid’ root program (*note How Change Persona::). As a consequence, installing a signal handler for the ‘SIGCHLD’ signal (*note Job Control Signals::) may interfere with a call to ‘grantpt’. The normal return value from ‘grantpt’ is 0; a value of -1 is returned in case of failure. The following ‘errno’ error conditions are defined for this function: ‘EBADF’ The FILEDES argument is not a valid file descriptor. ‘EINVAL’ The FILEDES argument is not associated with a master pseudo-terminal device. ‘EACCES’ The slave pseudo-terminal device corresponding to the master associated with FILEDES could not be accessed. -- Function: int unlockpt (int FILEDES) Preliminary: | MT-Safe | AS-Unsafe heap/bsd | AC-Unsafe mem fd | *Note POSIX Safety Concepts::. The ‘unlockpt’ function unlocks the slave pseudo-terminal device corresponding to the master pseudo-terminal device associated with the file descriptor FILEDES. On many systems, the slave can only be opened after unlocking, so portable applications should always call ‘unlockpt’ before trying to open the slave. The normal return value from ‘unlockpt’ is 0; a value of -1 is returned in case of failure. The following ‘errno’ error conditions are defined for this function: ‘EBADF’ The FILEDES argument is not a valid file descriptor. ‘EINVAL’ The FILEDES argument is not associated with a master pseudo-terminal device. -- Function: char * ptsname (int FILEDES) Preliminary: | MT-Unsafe race:ptsname | AS-Unsafe heap/bsd | AC-Unsafe mem fd | *Note POSIX Safety Concepts::. If the file descriptor FILEDES is associated with a master pseudo-terminal device, the ‘ptsname’ function returns a pointer to a statically-allocated, null-terminated string containing the file name of the associated slave pseudo-terminal file. This string might be overwritten by subsequent calls to ‘ptsname’. -- Function: int ptsname_r (int FILEDES, char *BUF, size_t LEN) Preliminary: | MT-Safe | AS-Unsafe heap/bsd | AC-Unsafe mem fd | *Note POSIX Safety Concepts::. The ‘ptsname_r’ function is similar to the ‘ptsname’ function except that it places its result into the user-specified buffer starting at BUF with length LEN. This function is a GNU extension. *Portability Note:* On System V derived systems, the file returned by the ‘ptsname’ and ‘ptsname_r’ functions may be STREAMS-based, and therefore require additional processing after opening before it actually behaves as a pseudo terminal. Typical usage of these functions is illustrated by the following example: int open_pty_pair (int *amaster, int *aslave) { int master, slave; char *name; master = getpt (); if (master < 0) return 0; if (grantpt (master) < 0 || unlockpt (master) < 0) goto close_master; name = ptsname (master); if (name == NULL) goto close_master; slave = open (name, O_RDWR); if (slave == -1) goto close_master; if (isastream (slave)) { if (ioctl (slave, I_PUSH, "ptem") < 0 || ioctl (slave, I_PUSH, "ldterm") < 0) goto close_slave; } *amaster = master; *aslave = slave; return 1; close_slave: close (slave); close_master: close (master); return 0; }  File: libc.info, Node: Pseudo-Terminal Pairs, Prev: Allocation, Up: Pseudo-Terminals 17.9.2 Opening a Pseudo-Terminal Pair ------------------------------------- These functions, derived from BSD, are available in the separate ‘libutil’ library, and declared in ‘pty.h’. -- Function: int openpty (int *AMASTER, int *ASLAVE, char *NAME, const struct termios *TERMP, const struct winsize *WINP) Preliminary: | MT-Safe locale | AS-Unsafe dlopen plugin heap lock | AC-Unsafe corrupt lock fd mem | *Note POSIX Safety Concepts::. This function allocates and opens a pseudo-terminal pair, returning the file descriptor for the master in *AMASTER, and the file descriptor for the slave in *ASLAVE. If the argument NAME is not a null pointer, the file name of the slave pseudo-terminal device is stored in ‘*name’. If TERMP is not a null pointer, the terminal attributes of the slave are set to the ones specified in the structure that TERMP points to (*note Terminal Modes::). Likewise, if WINP is not a null pointer, the screen size of the slave is set to the values specified in the structure that WINP points to. The normal return value from ‘openpty’ is 0; a value of -1 is returned in case of failure. The following ‘errno’ conditions are defined for this function: ‘ENOENT’ There are no free pseudo-terminal pairs available. *Warning:* Using the ‘openpty’ function with NAME not set to ‘NULL’ is *very dangerous* because it provides no protection against overflowing the string NAME. You should use the ‘ttyname’ function on the file descriptor returned in *SLAVE to find out the file name of the slave pseudo-terminal device instead. -- Function: int forkpty (int *AMASTER, char *NAME, const struct termios *TERMP, const struct winsize *WINP) Preliminary: | MT-Safe locale | AS-Unsafe dlopen plugin heap lock | AC-Unsafe corrupt lock fd mem | *Note POSIX Safety Concepts::. This function is similar to the ‘openpty’ function, but in addition, forks a new process (*note Creating a Process::) and makes the newly opened slave pseudo-terminal device the controlling terminal (*note Controlling Terminal::) for the child process. If the operation is successful, there are then both parent and child processes and both see ‘forkpty’ return, but with different values: it returns a value of 0 in the child process and returns the child’s process ID in the parent process. If the allocation of a pseudo-terminal pair or the process creation failed, ‘forkpty’ returns a value of -1 in the parent process. *Warning:* The ‘forkpty’ function has the same problems with respect to the NAME argument as ‘openpty’.  File: libc.info, Node: Syslog, Next: Mathematics, Prev: Low-Level Terminal Interface, Up: Top 18 Syslog ********* This chapter describes facilities for issuing and logging messages of system administration interest. This chapter has nothing to do with programs issuing messages to their own users or keeping private logs (One would typically do that with the facilities described in *note I/O on Streams::). Most systems have a facility called “Syslog” that allows programs to submit messages of interest to system administrators and can be configured to pass these messages on in various ways, such as printing on the console, mailing to a particular person, or recording in a log file for future reference. A program uses the facilities in this chapter to submit such messages. * Menu: * Overview of Syslog:: Overview of a system’s Syslog facility * Submitting Syslog Messages:: Functions to submit messages to Syslog  File: libc.info, Node: Overview of Syslog, Next: Submitting Syslog Messages, Up: Syslog 18.1 Overview of Syslog ======================= System administrators have to deal with lots of different kinds of messages from a plethora of subsystems within each system, and usually lots of systems as well. For example, an FTP server might report every connection it gets. The kernel might report hardware failures on a disk drive. A DNS server might report usage statistics at regular intervals. Some of these messages need to be brought to a system administrator’s attention immediately. And it may not be just any system administrator – there may be a particular system administrator who deals with a particular kind of message. Other messages just need to be recorded for future reference if there is a problem. Still others may need to have information extracted from them by an automated process that generates monthly reports. To deal with these messages, most Unix systems have a facility called "Syslog." It is generally based on a daemon called “Syslogd” Syslogd listens for messages on a Unix domain socket named ‘/dev/log’. Based on classification information in the messages and its configuration file (usually ‘/etc/syslog.conf’), Syslogd routes them in various ways. Some of the popular routings are: • Write to the system console • Mail to a specific user • Write to a log file • Pass to another daemon • Discard Syslogd can also handle messages from other systems. It listens on the ‘syslog’ UDP port as well as the local socket for messages. Syslog can handle messages from the kernel itself. But the kernel doesn’t write to ‘/dev/log’; rather, another daemon (sometimes called “Klogd”) extracts messages from the kernel and passes them on to Syslog as any other process would (and it properly identifies them as messages from the kernel). Syslog can even handle messages that the kernel issued before Syslogd or Klogd was running. A Linux kernel, for example, stores startup messages in a kernel message ring and they are normally still there when Klogd later starts up. Assuming Syslogd is running by the time Klogd starts, Klogd then passes everything in the message ring to it. In order to classify messages for disposition, Syslog requires any process that submits a message to it to provide two pieces of classification information with it: facility This identifies who submitted the message. There are a small number of facilities defined. The kernel, the mail subsystem, and an FTP server are examples of recognized facilities. For the complete list, *Note syslog; vsyslog::. Keep in mind that these are essentially arbitrary classifications. "Mail subsystem" doesn’t have any more meaning than the system administrator gives to it. priority This tells how important the content of the message is. Examples of defined priority values are: debug, informational, warning and critical. For the complete list, see *note syslog; vsyslog::. Except for the fact that the priorities have a defined order, the meaning of each of these priorities is entirely determined by the system administrator. A “facility/priority” is a number that indicates both the facility and the priority. *Warning:* This terminology is not universal. Some people use “level” to refer to the priority and “priority” to refer to the combination of facility and priority. A Linux kernel has a concept of a message “level,” which corresponds both to a Syslog priority and to a Syslog facility/priority (It can be both because the facility code for the kernel is zero, and that makes priority and facility/priority the same value). The GNU C Library provides functions to submit messages to Syslog. They do it by writing to the ‘/dev/log’ socket. *Note Submitting Syslog Messages::. The GNU C Library functions only work to submit messages to the Syslog facility on the same system. To submit a message to the Syslog facility on another system, use the socket I/O functions to write a UDP datagram to the ‘syslog’ UDP port on that system. *Note Sockets::.  File: libc.info, Node: Submitting Syslog Messages, Prev: Overview of Syslog, Up: Syslog 18.2 Submitting Syslog Messages =============================== The GNU C Library provides functions to submit messages to the Syslog facility: * Menu: * openlog:: Open connection to Syslog * syslog; vsyslog:: Submit message to Syslog * closelog:: Close connection to Syslog * setlogmask:: Cause certain messages to be ignored * Syslog Example:: Example of all of the above These functions only work to submit messages to the Syslog facility on the same system. To submit a message to the Syslog facility on another system, use the socket I/O functions to write a UDP datagram to the ‘syslog’ UDP port on that system. *Note Sockets::.  File: libc.info, Node: openlog, Next: syslog; vsyslog, Up: Submitting Syslog Messages 18.2.1 openlog -------------- The symbols referred to in this section are declared in the file ‘syslog.h’. -- Function: void openlog (const char *IDENT, int OPTION, int FACILITY) Preliminary: | MT-Safe | AS-Unsafe lock | AC-Unsafe lock fd | *Note POSIX Safety Concepts::. ‘openlog’ opens or reopens a connection to Syslog in preparation for submitting messages. IDENT is an arbitrary identification string which future ‘syslog’ invocations will prefix to each message. This is intended to identify the source of the message, and people conventionally set it to the name of the program that will submit the messages. If IDENT is NULL, or if ‘openlog’ is not called, the default identification string used in Syslog messages will be the program name, taken from argv[0]. Please note that the string pointer IDENT will be retained internally by the Syslog routines. You must not free the memory that IDENT points to. It is also dangerous to pass a reference to an automatic variable since leaving the scope would mean ending the lifetime of the variable. If you want to change the IDENT string, you must call ‘openlog’ again; overwriting the string pointed to by IDENT is not thread-safe. You can cause the Syslog routines to drop the reference to IDENT and go back to the default string (the program name taken from argv[0]), by calling ‘closelog’: *Note closelog::. In particular, if you are writing code for a shared library that might get loaded and then unloaded (e.g. a PAM module), and you use ‘openlog’, you must call ‘closelog’ before any point where your library might get unloaded, as in this example: #include void shared_library_function (void) { openlog ("mylibrary", option, priority); syslog (LOG_INFO, "shared library has been invoked"); closelog (); } Without the call to ‘closelog’, future invocations of ‘syslog’ by the program using the shared library may crash, if the library gets unloaded and the memory containing the string ‘"mylibrary"’ becomes unmapped. This is a limitation of the BSD syslog interface. ‘openlog’ may or may not open the ‘/dev/log’ socket, depending on OPTION. If it does, it tries to open it and connect it as a stream socket. If that doesn’t work, it tries to open it and connect it as a datagram socket. The socket has the “Close on Exec” attribute, so the kernel will close it if the process performs an exec. You don’t have to use ‘openlog’. If you call ‘syslog’ without having called ‘openlog’, ‘syslog’ just opens the connection implicitly and uses defaults for the information in IDENT and OPTIONS. OPTIONS is a bit string, with the bits as defined by the following single bit masks: ‘LOG_PERROR’ If on, ‘openlog’ sets up the connection so that any ‘syslog’ on this connection writes its message to the calling process’ Standard Error stream in addition to submitting it to Syslog. If off, ‘syslog’ does not write the message to Standard Error. ‘LOG_CONS’ If on, ‘openlog’ sets up the connection so that a ‘syslog’ on this connection that fails to submit a message to Syslog writes the message instead to system console. If off, ‘syslog’ does not write to the system console (but of course Syslog may write messages it receives to the console). ‘LOG_PID’ When on, ‘openlog’ sets up the connection so that a ‘syslog’ on this connection inserts the calling process’ Process ID (PID) into the message. When off, ‘openlog’ does not insert the PID. ‘LOG_NDELAY’ When on, ‘openlog’ opens and connects the ‘/dev/log’ socket. When off, a future ‘syslog’ call must open and connect the socket. *Portability note:* In early systems, the sense of this bit was exactly the opposite. ‘LOG_ODELAY’ This bit does nothing. It exists for backward compatibility. If any other bit in OPTIONS is on, the result is undefined. FACILITY is the default facility code for this connection. A ‘syslog’ on this connection that specifies default facility causes this facility to be associated with the message. See ‘syslog’ for possible values. A value of zero means the default, which is ‘LOG_USER’. If a Syslog connection is already open when you call ‘openlog’, ‘openlog’ “reopens” the connection. Reopening is like opening except that if you specify zero for the default facility code, the default facility code simply remains unchanged and if you specify LOG_NDELAY and the socket is already open and connected, ‘openlog’ just leaves it that way.  File: libc.info, Node: syslog; vsyslog, Next: closelog, Prev: openlog, Up: Submitting Syslog Messages 18.2.2 syslog, vsyslog ---------------------- The symbols referred to in this section are declared in the file ‘syslog.h’. -- Function: void syslog (int FACILITY_PRIORITY, const char *FORMAT, ...) Preliminary: | MT-Safe env locale | AS-Unsafe corrupt heap lock dlopen | AC-Unsafe corrupt lock mem fd | *Note POSIX Safety Concepts::. ‘syslog’ submits a message to the Syslog facility. It does this by writing to the Unix domain socket ‘/dev/log’. ‘syslog’ submits the message with the facility and priority indicated by FACILITY_PRIORITY. The macro ‘LOG_MAKEPRI’ generates a facility/priority from a facility and a priority, as in the following example: LOG_MAKEPRI(LOG_USER, LOG_WARNING) The possible values for the facility code are (macros): ‘LOG_USER’ A miscellaneous user process ‘LOG_MAIL’ Mail ‘LOG_DAEMON’ A miscellaneous system daemon ‘LOG_AUTH’ Security (authorization) ‘LOG_SYSLOG’ Syslog ‘LOG_LPR’ Central printer ‘LOG_NEWS’ Network news (e.g. Usenet) ‘LOG_UUCP’ UUCP ‘LOG_CRON’ Cron and At ‘LOG_AUTHPRIV’ Private security (authorization) ‘LOG_FTP’ Ftp server ‘LOG_LOCAL0’ Locally defined ‘LOG_LOCAL1’ Locally defined ‘LOG_LOCAL2’ Locally defined ‘LOG_LOCAL3’ Locally defined ‘LOG_LOCAL4’ Locally defined ‘LOG_LOCAL5’ Locally defined ‘LOG_LOCAL6’ Locally defined ‘LOG_LOCAL7’ Locally defined Results are undefined if the facility code is anything else. *NB:* ‘syslog’ recognizes one other facility code: that of the kernel. But you can’t specify that facility code with these functions. If you try, it looks the same to ‘syslog’ as if you are requesting the default facility. But you wouldn’t want to anyway, because any program that uses the GNU C Library is not the kernel. You can use just a priority code as FACILITY_PRIORITY. In that case, ‘syslog’ assumes the default facility established when the Syslog connection was opened. *Note Syslog Example::. The possible values for the priority code are (macros): ‘LOG_EMERG’ The message says the system is unusable. ‘LOG_ALERT’ Action on the message must be taken immediately. ‘LOG_CRIT’ The message states a critical condition. ‘LOG_ERR’ The message describes an error. ‘LOG_WARNING’ The message is a warning. ‘LOG_NOTICE’ The message describes a normal but important event. ‘LOG_INFO’ The message is purely informational. ‘LOG_DEBUG’ The message is only for debugging purposes. Results are undefined if the priority code is anything else. If the process does not presently have a Syslog connection open (i.e., it did not call ‘openlog’), ‘syslog’ implicitly opens the connection the same as ‘openlog’ would, with the following defaults for information that would otherwise be included in an ‘openlog’ call: The default identification string is the program name. The default default facility is ‘LOG_USER’. The default for all the connection options in OPTIONS is as if those bits were off. ‘syslog’ leaves the Syslog connection open. If the ‘/dev/log’ socket is not open and connected, ‘syslog’ opens and connects it, the same as ‘openlog’ with the ‘LOG_NDELAY’ option would. ‘syslog’ leaves ‘/dev/log’ open and connected unless its attempt to send the message failed, in which case ‘syslog’ closes it (with the hope that a future implicit open will restore the Syslog connection to a usable state). Example: #include syslog (LOG_MAKEPRI(LOG_LOCAL1, LOG_ERROR), "Unable to make network connection to %s. Error=%m", host); -- Function: void vsyslog (int FACILITY_PRIORITY, const char *FORMAT, va_list ARGLIST) Preliminary: | MT-Safe env locale | AS-Unsafe corrupt heap lock dlopen | AC-Unsafe corrupt lock mem fd | *Note POSIX Safety Concepts::. This is functionally identical to ‘syslog’, with the BSD style variable length argument.  File: libc.info, Node: closelog, Next: setlogmask, Prev: syslog; vsyslog, Up: Submitting Syslog Messages 18.2.3 closelog --------------- The symbols referred to in this section are declared in the file ‘syslog.h’. -- Function: void closelog (void) Preliminary: | MT-Safe | AS-Unsafe lock | AC-Unsafe lock fd | *Note POSIX Safety Concepts::. ‘closelog’ closes the current Syslog connection, if there is one. This includes closing the ‘/dev/log’ socket, if it is open. ‘closelog’ also sets the identification string for Syslog messages back to the default, if ‘openlog’ was called with a non-NULL argument to IDENT. The default identification string is the program name taken from argv[0]. If you are writing shared library code that uses ‘openlog’ to generate custom syslog output, you should use ‘closelog’ to drop the GNU C Library’s internal reference to the IDENT pointer when you are done. Please read the section on ‘openlog’ for more information: *Note openlog::. ‘closelog’ does not flush any buffers. You do not have to call ‘closelog’ before re-opening a Syslog connection with ‘openlog’. Syslog connections are automatically closed on exec or exit.  File: libc.info, Node: setlogmask, Next: Syslog Example, Prev: closelog, Up: Submitting Syslog Messages 18.2.4 setlogmask ----------------- The symbols referred to in this section are declared in the file ‘syslog.h’. -- Function: int setlogmask (int MASK) Preliminary: | MT-Unsafe race:LogMask | AS-Unsafe | AC-Safe | *Note POSIX Safety Concepts::. ‘setlogmask’ sets a mask (the “logmask”) that determines which future ‘syslog’ calls shall be ignored. If a program has not called ‘setlogmask’, ‘syslog’ doesn’t ignore any calls. You can use ‘setlogmask’ to specify that messages of particular priorities shall be ignored in the future. A ‘setlogmask’ call overrides any previous ‘setlogmask’ call. Note that the logmask exists entirely independently of opening and closing of Syslog connections. Setting the logmask has a similar effect to, but is not the same as, configuring Syslog. The Syslog configuration may cause Syslog to discard certain messages it receives, but the logmask causes certain messages never to get submitted to Syslog in the first place. MASK is a bit string with one bit corresponding to each of the possible message priorities. If the bit is on, ‘syslog’ handles messages of that priority normally. If it is off, ‘syslog’ discards messages of that priority. Use the message priority macros described in *note syslog; vsyslog:: and the ‘LOG_MASK’ to construct an appropriate MASK value, as in this example: LOG_MASK(LOG_EMERG) | LOG_MASK(LOG_ERROR) or ~(LOG_MASK(LOG_INFO)) There is also a ‘LOG_UPTO’ macro, which generates a mask with the bits on for a certain priority and all priorities above it: LOG_UPTO(LOG_ERROR) The unfortunate naming of the macro is due to the fact that internally, higher numbers are used for lower message priorities.  File: libc.info, Node: Syslog Example, Prev: setlogmask, Up: Submitting Syslog Messages 18.2.5 Syslog Example --------------------- Here is an example of ‘openlog’, ‘syslog’, and ‘closelog’: This example sets the logmask so that debug and informational messages get discarded without ever reaching Syslog. So the second ‘syslog’ in the example does nothing. #include setlogmask (LOG_UPTO (LOG_NOTICE)); openlog ("exampleprog", LOG_CONS | LOG_PID | LOG_NDELAY, LOG_LOCAL1); syslog (LOG_NOTICE, "Program started by User %d", getuid ()); syslog (LOG_INFO, "A tree falls in a forest"); closelog ();  File: libc.info, Node: Mathematics, Next: Arithmetic, Prev: Syslog, Up: Top 19 Mathematics ************** This chapter contains information about functions for performing mathematical computations, such as trigonometric functions. Most of these functions have prototypes declared in the header file ‘math.h’. The complex-valued functions are defined in ‘complex.h’. All mathematical functions which take a floating-point argument have three variants, one each for ‘double’, ‘float’, and ‘long double’ arguments. The ‘double’ versions are mostly defined in ISO C89. The ‘float’ and ‘long double’ versions are from the numeric extensions to C included in ISO C99. Which of the three versions of a function should be used depends on the situation. For most calculations, the ‘float’ functions are the fastest. On the other hand, the ‘long double’ functions have the highest precision. ‘double’ is somewhere in between. It is usually wise to pick the narrowest type that can accommodate your data. Not all machines have a distinct ‘long double’ type; it may be the same as ‘double’. The GNU C Library also provides ‘_FloatN’ and ‘_FloatNx’ types. These types are defined in ISO/IEC TS 18661-3, which extends ISO C and defines floating-point types that are not machine-dependent. When such a type, such as ‘_Float128’, is supported by the GNU C Library, extra variants for most of the mathematical functions provided for ‘double’, ‘float’, and ‘long double’ are also provided for the supported type. Throughout this manual, the ‘_FloatN’ and ‘_FloatNx’ variants of these functions are described along with the ‘double’, ‘float’, and ‘long double’ variants and they come from ISO/IEC TS 18661-3, unless explicitly stated otherwise. Support for ‘_FloatN’ or ‘_FloatNx’ types is provided for ‘_Float32’, ‘_Float64’ and ‘_Float32x’ on all platforms. It is also provided for ‘_Float128’ and ‘_Float64x’ on powerpc64le (PowerPC 64-bits little-endian), x86_64, x86, ia64, aarch64, alpha, mips64, riscv, s390 and sparc. * Menu: * Mathematical Constants:: Precise numeric values for often-used constants. * Trig Functions:: Sine, cosine, tangent, and friends. * Inverse Trig Functions:: Arcsine, arccosine, etc. * Exponents and Logarithms:: Also pow and sqrt. * Hyperbolic Functions:: sinh, cosh, tanh, etc. * Special Functions:: Bessel, gamma, erf. * Errors in Math Functions:: Known Maximum Errors in Math Functions. * Pseudo-Random Numbers:: Functions for generating pseudo-random numbers. * FP Function Optimizations:: Fast code or small code.  File: libc.info, Node: Mathematical Constants, Next: Trig Functions, Up: Mathematics 19.1 Predefined Mathematical Constants ====================================== The header ‘math.h’ defines several useful mathematical constants. All values are defined as preprocessor macros starting with ‘M_’. The values provided are: ‘M_E’ The base of natural logarithms. ‘M_LOG2E’ The logarithm to base ‘2’ of ‘M_E’. ‘M_LOG10E’ The logarithm to base ‘10’ of ‘M_E’. ‘M_LN2’ The natural logarithm of ‘2’. ‘M_LN10’ The natural logarithm of ‘10’. ‘M_PI’ Pi, the ratio of a circle’s circumference to its diameter. ‘M_PI_2’ Pi divided by two. ‘M_PI_4’ Pi divided by four. ‘M_1_PI’ The reciprocal of pi (1/pi) ‘M_2_PI’ Two times the reciprocal of pi. ‘M_2_SQRTPI’ Two times the reciprocal of the square root of pi. ‘M_SQRT2’ The square root of two. ‘M_SQRT1_2’ The reciprocal of the square root of two (also the square root of 1/2). These constants come from the Unix98 standard and were also available in 4.4BSD; therefore they are only defined if ‘_XOPEN_SOURCE=500’, or a more general feature select macro, is defined. The default set of features includes these constants. *Note Feature Test Macros::. All values are of type ‘double’. As an extension, the GNU C Library also defines these constants with type ‘long double’. The ‘long double’ macros have a lowercase ‘l’ appended to their names: ‘M_El’, ‘M_PIl’, and so forth. These are only available if ‘_GNU_SOURCE’ is defined. Likewise, the GNU C Library also defines these constants with the types ‘_FloatN’ and ‘_FloatNx’ for the machines that have support for such types enabled (*note Mathematics::) and if ‘_GNU_SOURCE’ is defined. When available, the macros names are appended with ‘fN’ or ‘fNx’, such as ‘f128’ for the type ‘_Float128’. _Note:_ Some programs use a constant named ‘PI’ which has the same value as ‘M_PI’. This constant is not standard; it may have appeared in some old AT&T headers, and is mentioned in Stroustrup’s book on C++. It infringes on the user’s name space, so the GNU C Library does not define it. Fixing programs written to expect it is simple: replace ‘PI’ with ‘M_PI’ throughout, or put ‘-DPI=M_PI’ on the compiler command line.  File: libc.info, Node: Trig Functions, Next: Inverse Trig Functions, Prev: Mathematical Constants, Up: Mathematics 19.2 Trigonometric Functions ============================ These are the familiar ‘sin’, ‘cos’, and ‘tan’ functions. The arguments to all of these functions are in units of radians; recall that pi radians equals 180 degrees. The math library normally defines ‘M_PI’ to a ‘double’ approximation of pi. If strict ISO and/or POSIX compliance are requested this constant is not defined, but you can easily define it yourself: #define M_PI 3.14159265358979323846264338327 You can also compute the value of pi with the expression ‘acos (-1.0)’. -- Function: double sin (double X) -- Function: float sinf (float X) -- Function: long double sinl (long double X) -- Function: _FloatN sinfN (_FloatN X) -- Function: _FloatNx sinfNx (_FloatNx X) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions return the sine of X, where X is given in radians. The return value is in the range ‘-1’ to ‘1’. -- Function: double cos (double X) -- Function: float cosf (float X) -- Function: long double cosl (long double X) -- Function: _FloatN cosfN (_FloatN X) -- Function: _FloatNx cosfNx (_FloatNx X) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions return the cosine of X, where X is given in radians. The return value is in the range ‘-1’ to ‘1’. -- Function: double tan (double X) -- Function: float tanf (float X) -- Function: long double tanl (long double X) -- Function: _FloatN tanfN (_FloatN X) -- Function: _FloatNx tanfNx (_FloatNx X) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions return the tangent of X, where X is given in radians. Mathematically, the tangent function has singularities at odd multiples of pi/2. If the argument X is too close to one of these singularities, ‘tan’ will signal overflow. In many applications where ‘sin’ and ‘cos’ are used, the sine and cosine of the same angle are needed at the same time. It is more efficient to compute them simultaneously, so the library provides a function to do that. -- Function: void sincos (double X, double *SINX, double *COSX) -- Function: void sincosf (float X, float *SINX, float *COSX) -- Function: void sincosl (long double X, long double *SINX, long double *COSX) -- Function: _FloatN sincosfN (_FloatN X, _FloatN *SINX, _FloatN *COSX) -- Function: _FloatNx sincosfNx (_FloatNx X, _FloatNx *SINX, _FloatNx *COSX) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions return the sine of X in ‘*SINX’ and the cosine of X in ‘*COSX’, where X is given in radians. Both values, ‘*SINX’ and ‘*COSX’, are in the range of ‘-1’ to ‘1’. All these functions, including the ‘_FloatN’ and ‘_FloatNx’ variants, are GNU extensions. Portable programs should be prepared to cope with their absence. ISO C99 defines variants of the trig functions which work on complex numbers. The GNU C Library provides these functions, but they are only useful if your compiler supports the new complex types defined by the standard. (As of this writing GCC supports complex numbers, but there are bugs in the implementation.) -- Function: complex double csin (complex double Z) -- Function: complex float csinf (complex float Z) -- Function: complex long double csinl (complex long double Z) -- Function: complex _FloatN csinfN (complex _FloatN Z) -- Function: complex _FloatNx csinfNx (complex _FloatNx Z) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions return the complex sine of Z. The mathematical definition of the complex sine is sin (z) = 1/(2*i) * (exp (z*i) - exp (-z*i)). -- Function: complex double ccos (complex double Z) -- Function: complex float ccosf (complex float Z) -- Function: complex long double ccosl (complex long double Z) -- Function: complex _FloatN ccosfN (complex _FloatN Z) -- Function: complex _FloatNx ccosfNx (complex _FloatNx Z) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions return the complex cosine of Z. The mathematical definition of the complex cosine is cos (z) = 1/2 * (exp (z*i) + exp (-z*i)) -- Function: complex double ctan (complex double Z) -- Function: complex float ctanf (complex float Z) -- Function: complex long double ctanl (complex long double Z) -- Function: complex _FloatN ctanfN (complex _FloatN Z) -- Function: complex _FloatNx ctanfNx (complex _FloatNx Z) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions return the complex tangent of Z. The mathematical definition of the complex tangent is tan (z) = -i * (exp (z*i) - exp (-z*i)) / (exp (z*i) + exp (-z*i)) The complex tangent has poles at pi/2 + 2n, where n is an integer. ‘ctan’ may signal overflow if Z is too close to a pole.  File: libc.info, Node: Inverse Trig Functions, Next: Exponents and Logarithms, Prev: Trig Functions, Up: Mathematics 19.3 Inverse Trigonometric Functions ==================================== These are the usual arcsine, arccosine and arctangent functions, which are the inverses of the sine, cosine and tangent functions respectively. -- Function: double asin (double X) -- Function: float asinf (float X) -- Function: long double asinl (long double X) -- Function: _FloatN asinfN (_FloatN X) -- Function: _FloatNx asinfNx (_FloatNx X) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions compute the arcsine of X—that is, the value whose sine is X. The value is in units of radians. Mathematically, there are infinitely many such values; the one actually returned is the one between ‘-pi/2’ and ‘pi/2’ (inclusive). The arcsine function is defined mathematically only over the domain ‘-1’ to ‘1’. If X is outside the domain, ‘asin’ signals a domain error. -- Function: double acos (double X) -- Function: float acosf (float X) -- Function: long double acosl (long double X) -- Function: _FloatN acosfN (_FloatN X) -- Function: _FloatNx acosfNx (_FloatNx X) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions compute the arccosine of X—that is, the value whose cosine is X. The value is in units of radians. Mathematically, there are infinitely many such values; the one actually returned is the one between ‘0’ and ‘pi’ (inclusive). The arccosine function is defined mathematically only over the domain ‘-1’ to ‘1’. If X is outside the domain, ‘acos’ signals a domain error. -- Function: double atan (double X) -- Function: float atanf (float X) -- Function: long double atanl (long double X) -- Function: _FloatN atanfN (_FloatN X) -- Function: _FloatNx atanfNx (_FloatNx X) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions compute the arctangent of X—that is, the value whose tangent is X. The value is in units of radians. Mathematically, there are infinitely many such values; the one actually returned is the one between ‘-pi/2’ and ‘pi/2’ (inclusive). -- Function: double atan2 (double Y, double X) -- Function: float atan2f (float Y, float X) -- Function: long double atan2l (long double Y, long double X) -- Function: _FloatN atan2fN (_FloatN Y, _FloatN X) -- Function: _FloatNx atan2fNx (_FloatNx Y, _FloatNx X) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. This function computes the arctangent of Y/X, but the signs of both arguments are used to determine the quadrant of the result, and X is permitted to be zero. The return value is given in radians and is in the range ‘-pi’ to ‘pi’, inclusive. If X and Y are coordinates of a point in the plane, ‘atan2’ returns the signed angle between the line from the origin to that point and the x-axis. Thus, ‘atan2’ is useful for converting Cartesian coordinates to polar coordinates. (To compute the radial coordinate, use ‘hypot’; see *note Exponents and Logarithms::.) If both X and Y are zero, ‘atan2’ returns zero. ISO C99 defines complex versions of the inverse trig functions. -- Function: complex double casin (complex double Z) -- Function: complex float casinf (complex float Z) -- Function: complex long double casinl (complex long double Z) -- Function: complex _FloatN casinfN (complex _FloatN Z) -- Function: complex _FloatNx casinfNx (complex _FloatNx Z) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions compute the complex arcsine of Z—that is, the value whose sine is Z. The value returned is in radians. Unlike the real-valued functions, ‘casin’ is defined for all values of Z. -- Function: complex double cacos (complex double Z) -- Function: complex float cacosf (complex float Z) -- Function: complex long double cacosl (complex long double Z) -- Function: complex _FloatN cacosfN (complex _FloatN Z) -- Function: complex _FloatNx cacosfNx (complex _FloatNx Z) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions compute the complex arccosine of Z—that is, the value whose cosine is Z. The value returned is in radians. Unlike the real-valued functions, ‘cacos’ is defined for all values of Z. -- Function: complex double catan (complex double Z) -- Function: complex float catanf (complex float Z) -- Function: complex long double catanl (complex long double Z) -- Function: complex _FloatN catanfN (complex _FloatN Z) -- Function: complex _FloatNx catanfNx (complex _FloatNx Z) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions compute the complex arctangent of Z—that is, the value whose tangent is Z. The value is in units of radians.  File: libc.info, Node: Exponents and Logarithms, Next: Hyperbolic Functions, Prev: Inverse Trig Functions, Up: Mathematics 19.4 Exponentiation and Logarithms ================================== -- Function: double exp (double X) -- Function: float expf (float X) -- Function: long double expl (long double X) -- Function: _FloatN expfN (_FloatN X) -- Function: _FloatNx expfNx (_FloatNx X) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions compute ‘e’ (the base of natural logarithms) raised to the power X. If the magnitude of the result is too large to be representable, ‘exp’ signals overflow. -- Function: double exp2 (double X) -- Function: float exp2f (float X) -- Function: long double exp2l (long double X) -- Function: _FloatN exp2fN (_FloatN X) -- Function: _FloatNx exp2fNx (_FloatNx X) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions compute ‘2’ raised to the power X. Mathematically, ‘exp2 (x)’ is the same as ‘exp (x * log (2))’. -- Function: double exp10 (double X) -- Function: float exp10f (float X) -- Function: long double exp10l (long double X) -- Function: _FloatN exp10fN (_FloatN X) -- Function: _FloatNx exp10fNx (_FloatNx X) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions compute ‘10’ raised to the power X. Mathematically, ‘exp10 (x)’ is the same as ‘exp (x * log (10))’. The ‘exp10’ functions are from TS 18661-4:2015. -- Function: double log (double X) -- Function: float logf (float X) -- Function: long double logl (long double X) -- Function: _FloatN logfN (_FloatN X) -- Function: _FloatNx logfNx (_FloatNx X) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions compute the natural logarithm of X. ‘exp (log (X))’ equals X, exactly in mathematics and approximately in C. If X is negative, ‘log’ signals a domain error. If X is zero, it returns negative infinity; if X is too close to zero, it may signal overflow. -- Function: double log10 (double X) -- Function: float log10f (float X) -- Function: long double log10l (long double X) -- Function: _FloatN log10fN (_FloatN X) -- Function: _FloatNx log10fNx (_FloatNx X) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions return the base-10 logarithm of X. ‘log10 (X)’ equals ‘log (X) / log (10)’. -- Function: double log2 (double X) -- Function: float log2f (float X) -- Function: long double log2l (long double X) -- Function: _FloatN log2fN (_FloatN X) -- Function: _FloatNx log2fNx (_FloatNx X) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions return the base-2 logarithm of X. ‘log2 (X)’ equals ‘log (X) / log (2)’. -- Function: double logb (double X) -- Function: float logbf (float X) -- Function: long double logbl (long double X) -- Function: _FloatN logbfN (_FloatN X) -- Function: _FloatNx logbfNx (_FloatNx X) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions extract the exponent of X and return it as a floating-point value. If ‘FLT_RADIX’ is two, ‘logb’ is equal to ‘floor (log2 (x))’, except it’s probably faster. If X is de-normalized, ‘logb’ returns the exponent X would have if it were normalized. If X is infinity (positive or negative), ‘logb’ returns oo. If X is zero, ‘logb’ returns oo. It does not signal. -- Function: int ilogb (double X) -- Function: int ilogbf (float X) -- Function: int ilogbl (long double X) -- Function: int ilogbfN (_FloatN X) -- Function: int ilogbfNx (_FloatNx X) -- Function: long int llogb (double X) -- Function: long int llogbf (float X) -- Function: long int llogbl (long double X) -- Function: long int llogbfN (_FloatN X) -- Function: long int llogbfNx (_FloatNx X) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions are equivalent to the corresponding ‘logb’ functions except that they return signed integer values. The ‘ilogb’, ‘ilogbf’, and ‘ilogbl’ functions are from ISO C99; the ‘llogb’, ‘llogbf’, ‘llogbl’ functions are from TS 18661-1:2014; the ‘ilogbfN’, ‘ilogbfNx’, ‘llogbfN’, and ‘llogbfNx’ functions are from TS 18661-3:2015. Since integers cannot represent infinity and NaN, ‘ilogb’ instead returns an integer that can’t be the exponent of a normal floating-point number. ‘math.h’ defines constants so you can check for this. -- Macro: int FP_ILOGB0 ‘ilogb’ returns this value if its argument is ‘0’. The numeric value is either ‘INT_MIN’ or ‘-INT_MAX’. This macro is defined in ISO C99. -- Macro: long int FP_LLOGB0 ‘llogb’ returns this value if its argument is ‘0’. The numeric value is either ‘LONG_MIN’ or ‘-LONG_MAX’. This macro is defined in TS 18661-1:2014. -- Macro: int FP_ILOGBNAN ‘ilogb’ returns this value if its argument is ‘NaN’. The numeric value is either ‘INT_MIN’ or ‘INT_MAX’. This macro is defined in ISO C99. -- Macro: long int FP_LLOGBNAN ‘llogb’ returns this value if its argument is ‘NaN’. The numeric value is either ‘LONG_MIN’ or ‘LONG_MAX’. This macro is defined in TS 18661-1:2014. These values are system specific. They might even be the same. The proper way to test the result of ‘ilogb’ is as follows: i = ilogb (f); if (i == FP_ILOGB0 || i == FP_ILOGBNAN) { if (isnan (f)) { /* Handle NaN. */ } else if (f == 0.0) { /* Handle 0.0. */ } else { /* Some other value with large exponent, perhaps +Inf. */ } } -- Function: double pow (double BASE, double POWER) -- Function: float powf (float BASE, float POWER) -- Function: long double powl (long double BASE, long double POWER) -- Function: _FloatN powfN (_FloatN BASE, _FloatN POWER) -- Function: _FloatNx powfNx (_FloatNx BASE, _FloatNx POWER) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These are general exponentiation functions, returning BASE raised to POWER. Mathematically, ‘pow’ would return a complex number when BASE is negative and POWER is not an integral value. ‘pow’ can’t do that, so instead it signals a domain error. ‘pow’ may also underflow or overflow the destination type. -- Function: double sqrt (double X) -- Function: float sqrtf (float X) -- Function: long double sqrtl (long double X) -- Function: _FloatN sqrtfN (_FloatN X) -- Function: _FloatNx sqrtfNx (_FloatNx X) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions return the nonnegative square root of X. If X is negative, ‘sqrt’ signals a domain error. Mathematically, it should return a complex number. -- Function: double cbrt (double X) -- Function: float cbrtf (float X) -- Function: long double cbrtl (long double X) -- Function: _FloatN cbrtfN (_FloatN X) -- Function: _FloatNx cbrtfNx (_FloatNx X) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions return the cube root of X. They cannot fail; every representable real value has a representable real cube root. -- Function: double hypot (double X, double Y) -- Function: float hypotf (float X, float Y) -- Function: long double hypotl (long double X, long double Y) -- Function: _FloatN hypotfN (_FloatN X, _FloatN Y) -- Function: _FloatNx hypotfNx (_FloatNx X, _FloatNx Y) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions return ‘sqrt (X*X + Y*Y)’. This is the length of the hypotenuse of a right triangle with sides of length X and Y, or the distance of the point (X, Y) from the origin. Using this function instead of the direct formula is wise, since the error is much smaller. See also the function ‘cabs’ in *note Absolute Value::. -- Function: double expm1 (double X) -- Function: float expm1f (float X) -- Function: long double expm1l (long double X) -- Function: _FloatN expm1fN (_FloatN X) -- Function: _FloatNx expm1fNx (_FloatNx X) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions return a value equivalent to ‘exp (X) - 1’. They are computed in a way that is accurate even if X is near zero—a case where ‘exp (X) - 1’ would be inaccurate owing to subtraction of two numbers that are nearly equal. -- Function: double log1p (double X) -- Function: float log1pf (float X) -- Function: long double log1pl (long double X) -- Function: _FloatN log1pfN (_FloatN X) -- Function: _FloatNx log1pfNx (_FloatNx X) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions return a value equivalent to ‘log (1 + X)’. They are computed in a way that is accurate even if X is near zero. ISO C99 defines complex variants of some of the exponentiation and logarithm functions. -- Function: complex double cexp (complex double Z) -- Function: complex float cexpf (complex float Z) -- Function: complex long double cexpl (complex long double Z) -- Function: complex _FloatN cexpfN (complex _FloatN Z) -- Function: complex _FloatNx cexpfNx (complex _FloatNx Z) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions return ‘e’ (the base of natural logarithms) raised to the power of Z. Mathematically, this corresponds to the value exp (z) = exp (creal (z)) * (cos (cimag (z)) + I * sin (cimag (z))) -- Function: complex double clog (complex double Z) -- Function: complex float clogf (complex float Z) -- Function: complex long double clogl (complex long double Z) -- Function: complex _FloatN clogfN (complex _FloatN Z) -- Function: complex _FloatNx clogfNx (complex _FloatNx Z) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions return the natural logarithm of Z. Mathematically, this corresponds to the value log (z) = log (cabs (z)) + I * carg (z) ‘clog’ has a pole at 0, and will signal overflow if Z equals or is very close to 0. It is well-defined for all other values of Z. -- Function: complex double clog10 (complex double Z) -- Function: complex float clog10f (complex float Z) -- Function: complex long double clog10l (complex long double Z) -- Function: complex _FloatN clog10fN (complex _FloatN Z) -- Function: complex _FloatNx clog10fNx (complex _FloatNx Z) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions return the base 10 logarithm of the complex value Z. Mathematically, this corresponds to the value log10 (z) = log10 (cabs (z)) + I * carg (z) / log (10) All these functions, including the ‘_FloatN’ and ‘_FloatNx’ variants, are GNU extensions. -- Function: complex double csqrt (complex double Z) -- Function: complex float csqrtf (complex float Z) -- Function: complex long double csqrtl (complex long double Z) -- Function: complex _FloatN csqrtfN (_FloatN Z) -- Function: complex _FloatNx csqrtfNx (complex _FloatNx Z) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions return the complex square root of the argument Z. Unlike the real-valued functions, they are defined for all values of Z. -- Function: complex double cpow (complex double BASE, complex double POWER) -- Function: complex float cpowf (complex float BASE, complex float POWER) -- Function: complex long double cpowl (complex long double BASE, complex long double POWER) -- Function: complex _FloatN cpowfN (complex _FloatN BASE, complex _FloatN POWER) -- Function: complex _FloatNx cpowfNx (complex _FloatNx BASE, complex _FloatNx POWER) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions return BASE raised to the power of POWER. This is equivalent to ‘cexp (y * clog (x))’  File: libc.info, Node: Hyperbolic Functions, Next: Special Functions, Prev: Exponents and Logarithms, Up: Mathematics 19.5 Hyperbolic Functions ========================= The functions in this section are related to the exponential functions; see *note Exponents and Logarithms::. -- Function: double sinh (double X) -- Function: float sinhf (float X) -- Function: long double sinhl (long double X) -- Function: _FloatN sinhfN (_FloatN X) -- Function: _FloatNx sinhfNx (_FloatNx X) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions return the hyperbolic sine of X, defined mathematically as ‘(exp (X) - exp (-X)) / 2’. They may signal overflow if X is too large. -- Function: double cosh (double X) -- Function: float coshf (float X) -- Function: long double coshl (long double X) -- Function: _FloatN coshfN (_FloatN X) -- Function: _FloatNx coshfNx (_FloatNx X) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions return the hyperbolic cosine of X, defined mathematically as ‘(exp (X) + exp (-X)) / 2’. They may signal overflow if X is too large. -- Function: double tanh (double X) -- Function: float tanhf (float X) -- Function: long double tanhl (long double X) -- Function: _FloatN tanhfN (_FloatN X) -- Function: _FloatNx tanhfNx (_FloatNx X) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions return the hyperbolic tangent of X, defined mathematically as ‘sinh (X) / cosh (X)’. They may signal overflow if X is too large. There are counterparts for the hyperbolic functions which take complex arguments. -- Function: complex double csinh (complex double Z) -- Function: complex float csinhf (complex float Z) -- Function: complex long double csinhl (complex long double Z) -- Function: complex _FloatN csinhfN (complex _FloatN Z) -- Function: complex _FloatNx csinhfNx (complex _FloatNx Z) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions return the complex hyperbolic sine of Z, defined mathematically as ‘(exp (Z) - exp (-Z)) / 2’. -- Function: complex double ccosh (complex double Z) -- Function: complex float ccoshf (complex float Z) -- Function: complex long double ccoshl (complex long double Z) -- Function: complex _FloatN ccoshfN (complex _FloatN Z) -- Function: complex _FloatNx ccoshfNx (complex _FloatNx Z) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions return the complex hyperbolic cosine of Z, defined mathematically as ‘(exp (Z) + exp (-Z)) / 2’. -- Function: complex double ctanh (complex double Z) -- Function: complex float ctanhf (complex float Z) -- Function: complex long double ctanhl (complex long double Z) -- Function: complex _FloatN ctanhfN (complex _FloatN Z) -- Function: complex _FloatNx ctanhfNx (complex _FloatNx Z) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions return the complex hyperbolic tangent of Z, defined mathematically as ‘csinh (Z) / ccosh (Z)’. -- Function: double asinh (double X) -- Function: float asinhf (float X) -- Function: long double asinhl (long double X) -- Function: _FloatN asinhfN (_FloatN X) -- Function: _FloatNx asinhfNx (_FloatNx X) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions return the inverse hyperbolic sine of X—the value whose hyperbolic sine is X. -- Function: double acosh (double X) -- Function: float acoshf (float X) -- Function: long double acoshl (long double X) -- Function: _FloatN acoshfN (_FloatN X) -- Function: _FloatNx acoshfNx (_FloatNx X) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions return the inverse hyperbolic cosine of X—the value whose hyperbolic cosine is X. If X is less than ‘1’, ‘acosh’ signals a domain error. -- Function: double atanh (double X) -- Function: float atanhf (float X) -- Function: long double atanhl (long double X) -- Function: _FloatN atanhfN (_FloatN X) -- Function: _FloatNx atanhfNx (_FloatNx X) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions return the inverse hyperbolic tangent of X—the value whose hyperbolic tangent is X. If the absolute value of X is greater than ‘1’, ‘atanh’ signals a domain error; if it is equal to 1, ‘atanh’ returns infinity. -- Function: complex double casinh (complex double Z) -- Function: complex float casinhf (complex float Z) -- Function: complex long double casinhl (complex long double Z) -- Function: complex _FloatN casinhfN (complex _FloatN Z) -- Function: complex _FloatNx casinhfNx (complex _FloatNx Z) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions return the inverse complex hyperbolic sine of Z—the value whose complex hyperbolic sine is Z. -- Function: complex double cacosh (complex double Z) -- Function: complex float cacoshf (complex float Z) -- Function: complex long double cacoshl (complex long double Z) -- Function: complex _FloatN cacoshfN (complex _FloatN Z) -- Function: complex _FloatNx cacoshfNx (complex _FloatNx Z) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions return the inverse complex hyperbolic cosine of Z—the value whose complex hyperbolic cosine is Z. Unlike the real-valued functions, there are no restrictions on the value of Z. -- Function: complex double catanh (complex double Z) -- Function: complex float catanhf (complex float Z) -- Function: complex long double catanhl (complex long double Z) -- Function: complex _FloatN catanhfN (complex _FloatN Z) -- Function: complex _FloatNx catanhfNx (complex _FloatNx Z) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. These functions return the inverse complex hyperbolic tangent of Z—the value whose complex hyperbolic tangent is Z. Unlike the real-valued functions, there are no restrictions on the value of Z.  File: libc.info, Node: Special Functions, Next: Errors in Math Functions, Prev: Hyperbolic Functions, Up: Mathematics 19.6 Special Functions ====================== These are some more exotic mathematical functions which are sometimes useful. Currently they only have real-valued versions. -- Function: double erf (double X) -- Function: float erff (float X) -- Function: long double erfl (long double X) -- Function: _FloatN erffN (_FloatN X) -- Function: _FloatNx erffNx (_FloatNx X) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. ‘erf’ returns the error function of X. The error function is defined as erf (x) = 2/sqrt(pi) * integral from 0 to x of exp(-t^2) dt -- Function: double erfc (double X) -- Function: float erfcf (float X) -- Function: long double erfcl (long double X) -- Function: _FloatN erfcfN (_FloatN X) -- Function: _FloatNx erfcfNx (_FloatNx X) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. ‘erfc’ returns ‘1.0 - erf(X)’, but computed in a fashion that avoids round-off error when X is large. -- Function: double lgamma (double X) -- Function: float lgammaf (float X) -- Function: long double lgammal (long double X) -- Function: _FloatN lgammafN (_FloatN X) -- Function: _FloatNx lgammafNx (_FloatNx X) Preliminary: | MT-Unsafe race:signgam | AS-Unsafe | AC-Safe | *Note POSIX Safety Concepts::. ‘lgamma’ returns the natural logarithm of the absolute value of the gamma function of X. The gamma function is defined as gamma (x) = integral from 0 to oo of t^(x-1) e^-t dt The sign of the gamma function is stored in the global variable SIGNGAM, which is declared in ‘math.h’. It is ‘1’ if the intermediate result was positive or zero, or ‘-1’ if it was negative. To compute the real gamma function you can use the ‘tgamma’ function or you can compute the values as follows: lgam = lgamma(x); gam = signgam*exp(lgam); The gamma function has singularities at the non-positive integers. ‘lgamma’ will raise the zero divide exception if evaluated at a singularity. -- Function: double lgamma_r (double X, int *SIGNP) -- Function: float lgammaf_r (float X, int *SIGNP) -- Function: long double lgammal_r (long double X, int *SIGNP) -- Function: _FloatN lgammafN_r (_FloatN X, int *SIGNP) -- Function: _FloatNx lgammafNx_r (_FloatNx X, int *SIGNP) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. ‘lgamma_r’ is just like ‘lgamma’, but it stores the sign of the intermediate result in the variable pointed to by SIGNP instead of in the SIGNGAM global. This means it is reentrant. The ‘lgammafN_r’ and ‘lgammafNx_r’ functions are GNU extensions. -- Function: double gamma (double X) -- Function: float gammaf (float X) -- Function: long double gammal (long double X) Preliminary: | MT-Unsafe race:signgam | AS-Unsafe | AC-Safe | *Note POSIX Safety Concepts::. These functions exist for compatibility reasons. They are equivalent to ‘lgamma’ etc. It is better to use ‘lgamma’ since for one the name reflects better the actual computation, and moreover ‘lgamma’ is standardized in ISO C99 while ‘gamma’ is not. -- Function: double tgamma (double X) -- Function: float tgammaf (float X) -- Function: long double tgammal (long double X) -- Function: _FloatN tgammafN (_FloatN X) -- Function: _FloatNx tgammafNx (_FloatNx X) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. ‘tgamma’ applies the gamma function to X. The gamma function is defined as gamma (x) = integral from 0 to oo of t^(x-1) e^-t dt This function was introduced in ISO C99. The ‘_FloatN’ and ‘_FloatNx’ variants were introduced in ISO/IEC TS 18661-3. -- Function: double j0 (double X) -- Function: float j0f (float X) -- Function: long double j0l (long double X) -- Function: _FloatN j0fN (_FloatN X) -- Function: _FloatNx j0fNx (_FloatNx X) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. ‘j0’ returns the Bessel function of the first kind of order 0 of X. It may signal underflow if X is too large. The ‘_FloatN’ and ‘_FloatNx’ variants are GNU extensions. -- Function: double j1 (double X) -- Function: float j1f (float X) -- Function: long double j1l (long double X) -- Function: _FloatN j1fN (_FloatN X) -- Function: _FloatNx j1fNx (_FloatNx X) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. ‘j1’ returns the Bessel function of the first kind of order 1 of X. It may signal underflow if X is too large. The ‘_FloatN’ and ‘_FloatNx’ variants are GNU extensions. -- Function: double jn (int N, double X) -- Function: float jnf (int N, float X) -- Function: long double jnl (int N, long double X) -- Function: _FloatN jnfN (int N, _FloatN X) -- Function: _FloatNx jnfNx (int N, _FloatNx X) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. ‘jn’ returns the Bessel function of the first kind of order N of X. It may signal underflow if X is too large. The ‘_FloatN’ and ‘_FloatNx’ variants are GNU extensions. -- Function: double y0 (double X) -- Function: float y0f (float X) -- Function: long double y0l (long double X) -- Function: _FloatN y0fN (_FloatN X) -- Function: _FloatNx y0fNx (_FloatNx X) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. ‘y0’ returns the Bessel function of the second kind of order 0 of X. It may signal underflow if X is too large. If X is negative, ‘y0’ signals a domain error; if it is zero, ‘y0’ signals overflow and returns -oo. The ‘_FloatN’ and ‘_FloatNx’ variants are GNU extensions. -- Function: double y1 (double X) -- Function: float y1f (float X) -- Function: long double y1l (long double X) -- Function: _FloatN y1fN (_FloatN X) -- Function: _FloatNx y1fNx (_FloatNx X) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. ‘y1’ returns the Bessel function of the second kind of order 1 of X. It may signal underflow if X is too large. If X is negative, ‘y1’ signals a domain error; if it is zero, ‘y1’ signals overflow and returns -oo. The ‘_FloatN’ and ‘_FloatNx’ variants are GNU extensions. -- Function: double yn (int N, double X) -- Function: float ynf (int N, float X) -- Function: long double ynl (int N, long double X) -- Function: _FloatN ynfN (int N, _FloatN X) -- Function: _FloatNx ynfNx (int N, _FloatNx X) Preliminary: | MT-Safe | AS-Safe | AC-Safe | *Note POSIX Safety Concepts::. ‘yn’ returns the Bessel function of the second kind of order N of X. It may signal underflow if X is too large. If X is negative, ‘yn’ signals a domain error; if it is zero, ‘yn’ signals overflow and returns -oo. The ‘_FloatN’ and ‘_FloatNx’ variants are GNU extensions.  File: libc.info, Node: Errors in Math Functions, Next: Pseudo-Random Numbers, Prev: Special Functions, Up: Mathematics 19.7 Known Maximum Errors in Math Functions =========================================== This section lists the known errors of the functions in the math library. Errors are measured in “units of the last place”. This is a measure for the relative error. For a number z with the representation d.d...d*2^e (we assume IEEE floating-point numbers with base 2) the ULP is represented by |d.d...d - (z / 2^e)| / 2^(p - 1) where p is the number of bits in the mantissa of the floating-point number representation. Ideally the error for all functions is always less than 0.5ulps in round-to-nearest mode. Using rounding bits this is also possible and normally implemented for the basic operations. Except for certain functions such as ‘sqrt’, ‘fma’ and ‘rint’ whose results are fully specified by reference to corresponding IEEE 754 floating-point operations, and conversions between strings and floating point, the GNU C Library does not aim for correctly rounded results for functions in the math library, and does not aim for correctness in whether “inexact” exceptions are raised. Instead, the goals for accuracy of functions without fully specified results are as follows; some functions have bugs meaning they do not meet these goals in all cases. In the future, the GNU C Library may provide some other correctly rounding functions under the names such as ‘crsin’ proposed for an extension to ISO C. • Each function with a floating-point result behaves as if it computes an infinite-precision result that is within a few ulp (in both real and complex parts, for functions with complex results) of the mathematically correct value of the function (interpreted together with ISO C or POSIX semantics for the function in question) at the exact value passed as the input. Exceptions are raised appropriately for this value and in accordance with IEEE 754 / ISO C / POSIX semantics, and it is then rounded according to the current rounding direction to the result that is returned to the user. ‘errno’ may also be set (*note Math Error Reporting::). (The “inexact” exception may be raised, or not raised, even if this is inconsistent with the infinite-precision value.) • For the IBM ‘long double’ format, as used on PowerPC GNU/Linux, the accuracy goal is weaker for input values not exactly representable in 106 bits of precision; it is as if the input value is some value within 0.5ulp of the value actually passed, where “ulp” is interpreted in terms of a fixed-precision 106-bit mantissa, but not necessarily the exact value actually passed with discontiguous mantissa bits. • For the IBM ‘long double’ format, functions whose results are fully specified by reference to corresponding IEEE 754 floating-point operations have the same accuracy goals as other functions, but with the error bound being the same as that for division (3ulp). Furthermore, “inexact” and “underflow” exceptions may be raised for all functions for any inputs, even where such exceptions are inconsistent with the returned value, since the underlying floating-point arithmetic has that property. • Functions behave as if the infinite-precision result computed is zero, infinity or NaN if and only if that is the mathematically correct infinite-precision result. They behave as if the infinite-precision result computed always has the same sign as the mathematically correct result. • If the mathematical result is more than a few ulp above the overflow threshold for the current rounding direction, the value returned is the appropriate overflow value for the current rounding direction, with the overflow exception raised. • If the mathematical result has magnitude well below half the least subnormal magnitude, the returned value is either zero or the least subnormal (in each case, with the correct sign), according to the current rounding direction and with the underflow exception raised. • Where the mathematical result underflows (before rounding) and is not exactly representable as a floating-point value, the function does not behave as if the computed infinite-precision result is an exact value in the subnormal range. This means that the underflow exception is raised other than possibly for cases where the mathematical result is very close to the underflow threshold and the function behaves as if it computes an infinite-precision result that does not underflow. (So there may be spurious underflow exceptions in cases where the underflowing result is exact, but not missing underflow exceptions in cases where it is inexact.) • The GNU C Library does not aim for functions to satisfy other properties of the underlying mathematical function, such as monotonicity, where not implied by the above goals. • All the above applies to both real and complex parts, for complex functions. Therefore many of the functions in the math library have errors. The table lists the maximum error for each function which is exposed by one of the existing tests in the test suite. The table tries to cover as much as possible and list the actual maximum error (or at least a ballpark figure) but this is often not achieved due to the large search space. The table lists the ULP values for different architectures. Different architectures have different results since their hardware support for floating-point operations varies and also the existing hardware support is different. Only the round-to-nearest rounding mode is covered by this table, and vector versions of functions are not covered. Functions not listed do not have known errors. Function AArch64 ARM Alpha ColdFire Generic acosf 1 1 1 - - acos - - - - - acosl 1 - 1 - - acosf128 - - - - - acoshf 2 2 2 - - acosh 2 2 2 - - acoshl 2 - 2 - - acoshf128 - - - - - add_ldoublef - - - - - add_ldouble - - - - - add_ldoublel - - - - - add_ldoublef128- - - - - asinf 1 1 1 - - asin - - - - - asinl 1 - 1 - - asinf128 - - - - - asinhf 1 1 1 - - asinh 1 1 1 - - asinhl 3 - 3 - - asinhf128 - - - - - atanf 1 1 1 - - atan 1 - - - - atanl 1 - 1 - - atanf128 - - - - - atan2f 1 1 1 1 - atan2 - - - - - atan2l 1 - 1 - - atan2f128 - - - - - atanhf 2 2 2 1 - atanh 2 2 2 - - atanhl 3 - 3 - - atanhf128 - - - - - cabsf - - - - - cabs 1 1 1 - - cabsl 1 - 1 - - cabsf128 - - - - - cacosf 2 + i 2 2 + i 2 2 + i 2 - - cacos 1 + i 2 1 + i 2 1 + i 2 - - cacosl 2 + i 2 - 2 + i 2 - - cacosf128 - - - - - cacoshf 2 + i 2 2 + i 2 2 + i 2 0 + i 1 - cacosh 2 + i 1 2 + i 1 2 + i 1 - - cacoshl 2 + i 2 - 2 + i 2 - - cacoshf128 - - - - - cargf 1 1 1 - - carg 1 - - - - cargl 2 - 2 - - cargf128 - - - - - casinf 1 + i 2 1 + i 2 1 + i 2 1 + i 0 - casin 1 + i 2 1 + i 2 1 + i 2 1 + i 0 - casinl 2 + i 2 - 2 + i 2 - - casinf128 - - - - - casinhf 2 + i 1 2 + i 1 2 + i 1 1 + i 6 - casinh 2 + i 1 2 + i 1 2 + i 1 5 + i 3 - casinhl 2 + i 2 - 2 + i 2 - - casinhf128 - - - - - catanf 1 + i 1 1 + i 1 1 + i 1 0 + i 1 - catan 1 + i 1 1 + i 1 1 + i 1 0 + i 1 - catanl 1 + i 1 - 1 + i 1 - - catanf128 - - - - - catanhf 1 + i 1 1 + i 1 1 + i 1 - - catanh 1 + i 1 1 + i 1 1 + i 1 4 + i 0 - catanhl 1 + i 1 - 1 + i 1 - - catanhf128 - - - - - cbrtf 1 1 1 - - cbrt 3 3 3 1 - cbrtl 1 - 1 - - cbrtf128 - - - - - ccosf 1 + i 1 1 + i 1 1 + i 1 1 + i 1 - ccos 1 + i 1 1 + i 1 1 + i 1 1 + i 0 - ccosl 1 + i 1 - 1 + i 1 - - ccosf128 - - - - - ccoshf 1 + i 1 1 + i 1 1 + i 1 1 + i 1 - ccosh 1 + i 1 1 + i 1 1 + i 1 1 + i 0 - ccoshl 1 + i 1 - 1 + i 1 - - ccoshf128 - - - - - cexpf 1 + i 2 1 + i 2 1 + i 2 1 + i 1 - cexp 2 + i 1 2 + i 1 2 + i 1 - - cexpl 1 + i 1 - 1 + i 1 - - cexpf128 - - - - - clogf 3 + i 1 3 + i 1 3 + i 1 1 + i 0 - clog 3 + i 1 3 + i 0 3 + i 0 - - clogl 2 + i 1 - 2 + i 1 - - clogf128 - - - - - clog10f 4 + i 2 4 + i 2 4 + i 2 1 + i 1 - clog10 3 + i 2 3 + i 2 3 + i 2 0 + i 1 - clog10l 2 + i 2 - 2 + i 2 - - clog10f128 - - - - - cosf 1 1 1 1 - cos 1 1 1 2 - cosl 1 - 1 - - cosf128 - - - - - coshf 1 1 1 - - cosh 1 1 1 - - coshl 1 - 1 - - coshf128 - - - - - cpowf 5 + i 2 5 + i 2 5 + i 2 4 + i 2 - cpow 2 + i 0 2 + i 0 2 + i 0 2 + i 2 - cpowl 4 + i 1 - 4 + i 1 - - cpowf128 - - - - - csinf 1 + i 0 1 + i 0 1 + i 0 - - csin 1 + i 0 1 + i 0 1 + i 0 - - csinl 1 + i 1 - 1 + i 1 - - csinf128 - - - - - csinhf 1 + i 1 1 + i 1 1 + i 1 1 + i 1 - csinh 0 + i 1 0 + i 1 0 + i 1 0 + i 1 - csinhl 1 + i 1 - 1 + i 1 - - csinhf128 - - - - - csqrtf 2 + i 2 2 + i 2 2 + i 2 1 + i 0 - csqrt 2 + i 2 2 + i 2 2 + i 2 - - csqrtl 2 + i 2 - 2 + i 2 - - csqrtf128 - - - - - ctanf 1 + i 2 1 + i 2 1 + i 2 - - ctan 1 + i 2 1 + i 2 1 + i 2 0 + i 1 - ctanl 3 + i 3 - 3 + i 3 - - ctanf128 - - - - - ctanhf 2 + i 1 2 + i 2 2 + i 2 2 + i 1 - ctanh 2 + i 2 2 + i 2 2 + i 2 1 + i 0 - ctanhl 3 + i 3 - 3 + i 3 - - ctanhf128 - - - - - div_ldoublef - - - - - div_ldouble - - - - - div_ldoublel - - - - - div_ldoublef128- - - - - erff 1 1 1 - - erf 1 1 1 1 - erfl 1 - 1 - - erff128 - - - - - erfcf 2 2 2 - - erfc 2 3 3 1 - erfcl 2 - 2 - - erfcf128 - - - - - expf 1 1 1 - - exp - - - - - expl 1 - 1 - - expf128 - - - - - exp10f - - - 2 - exp10 2 2 2 6 - exp10l 2 - 2 - - exp10f128 - - - - - exp2f 1 1 1 - - exp2 1 1 1 - - exp2l 1 - 1 - - exp2f128 - - - - - expm1f 1 1 1 1 - expm1 1 1 1 1 - expm1l 1 - 1 - - expm1f128 - - - - - fmaf - - - - - fma - - - - - fmal - - - - - fmaf128 - - - - - fmodf - - - - - fmod - - - - - fmodl - - - - - fmodf128 - - - - - gammaf 4 4 4 - - gamma 3 4 4 - - gammal 5 - 5 - - gammaf128 - - - - - hypotf - - - 1 - hypot 1 1 1 - - hypotl 1 - 1 - - hypotf128 - - - - - j0f 2 2 2 2 - j0 2 2 2 2 - j0l 2 - 2 - - j0f128 - - - - - j1f 2 2 2 2 - j1 1 1 1 1 - j1l 4 - 4 - - j1f128 - - - - - jnf 4 4 4 4 - jn 4 4 4 4 - jnl 7 - 7 - - jnf128 - - - - - lgammaf 4 4 4 2 - lgamma 3 4 4 1 - lgammal 5 - 5 - - lgammaf128 - - - - - logf 1 1 1 - - log - - - - - logl 1 - 1 - - logf128 - - - - - log10f 2 2 2 2 - log10 2 2 2 1 - log10l 1 - 1 - - log10f128 - - - - - log1pf 1 1 1 1 - log1p 1 1 1 - - log1pl 2 - 2 - - log1pf128 - - - - - log2f 1 1 1 - - log2 1 2 2 - - log2l 2 - 2 - - log2f128 - - - - - mul_ldoublef - - - - - mul_ldouble - - - - - mul_ldoublel - - - - - mul_ldoublef128- - - - - powf 1 1 1 - - pow 1 1 1 - - powl 2 - 2 - - powf128 - - - - - sinf 1 1 1 - - sin 1 1 1 - - sinl 1 - 1 - - sinf128 - - - - - sincosf 1 1 1 1 - sincos 1 1 1 1 - sincosl 1 - 1 - - sincosf128 - - - - - sinhf 2 2 2 - - sinh 2 2 2 - - sinhl 2 - 2 - - sinhf128 - - - - - sqrtf - - - - - sqrt - - - - - sqrtl - - - - - sqrtf128 - - - - - sub_ldoublef - - - - - sub_ldouble - - - - - sub_ldoublel - - - - - sub_ldoublef128- - - - - tanf 1 1 1 - - tan - - - 1 - tanl 1 - 1 - - tanf128 - - - - - tanhf 2 2 2 - - tanh 2 2 2 - - tanhl 2 - 2 - - tanhf128 - - - - - tgammaf 4 4 4 1 - tgamma 5 5 5 1 - tgammal 4 - 4 - - tgammaf128 - - - - - y0f 1 1 1 1 - y0 2 2 2 2 - y0l 3 - 3 - - y0f128 - - - - - y1f 2 2 2 2 - y1 3 3 3 3 - y1l 2 - 2 - - y1f128 - - - - - ynf 3 3 3 2 - yn 3 3 3 3 - ynl 5 - 5 - - ynf128 - - - - - Function HPPA IA64 LoongArch LoongArch M68k 32-bit 64-bit acosf 1 - 1 1 - acos - 1 - - - acosl - - 1 1 - acosf128 - 1 - - - acoshf 2 - 2 2 1 acosh 2 1 2 2 1 acoshl - 1 2 2 1 acoshf128 - 2 - - - add_ldoublef - - - - - add_ldouble - - - - - add_ldoublel - - - - - add_ldoublef128- - - - - asinf 1 - 1 1 - asin - - - - - asinl - - 1 1 - asinf128 - 1 - - - asinhf 1 - 1 1 1 asinh 1 1 1 1 1 asinhl - - 3 3 1 asinhf128 - 3 - - - atanf 1 - 1 1 - atan - - - - - atanl - - 1 1 - atanf128 - 1 - - - atan2f 1 - 1 1 1 atan2 - - - - - atan2l - - 1 1 1 atan2f128 - 1 - - - atanhf 2 - 2 2 - atanh 2 - 2 2 - atanhl - - 3 3 - atanhf128 - 3 - - - cabsf - - - - - cabs 1 - 1 1 1 cabsl - - 1 1 1 cabsf128 - 1 - - - cacosf 2 + i 2 2 + i 2 2 + i 2 2 + i 2 2 + i 1 cacos 1 + i 2 1 + i 2 1 + i 2 1 + i 2 1 + i 1 cacosl - 1 + i 2 2 + i 2 2 + i 2 1 + i 2 cacosf128 - 2 + i 2 - - - cacoshf 2 + i 2 2 + i 2 2 + i 2 2 + i 2 1 + i 2 cacosh 2 + i 1 2 + i 1 2 + i 1 2 + i 1 1 + i 1 cacoshl - 2 + i 1 2 + i 2 2 + i 2 2 + i 1 cacoshf128 - 2 + i 2 - - - cargf 1 - 1 1 1 carg - - - - - cargl - - 2 2 1 cargf128 - 2 - - - casinf 1 + i 2 1 + i 2 1 + i 2 1 + i 2 1 + i 1 casin 1 + i 2 1 + i 2 1 + i 2 1 + i 2 1 + i 1 casinl 1 + i 0 1 + i 2 2 + i 2 2 + i 2 1 + i 2 casinf128 - 2 + i 2 - - - casinhf 2 + i 1 2 + i 1 2 + i 1 2 + i 1 1 + i 1 casinh 5 + i 3 2 + i 1 2 + i 1 2 + i 1 1 + i 1 casinhl 5 + i 3 2 + i 1 2 + i 2 2 + i 2 2 + i 1 casinhf128 - 2 + i 2 - - - catanf 1 + i 1 0 + i 1 1 + i 1 1 + i 1 0 + i 1 catan 1 + i 1 1 + i 1 1 + i 1 1 + i 1 0 + i 1 catanl 0 + i 1 0 + i 1 1 + i 1 1 + i 1 1 + i 1 catanf128 - 1 + i 1 - - - catanhf 1 + i 1 1 + i 0 1 + i 1 1 + i 1 1 + i 0 catanh 4 + i 1 1 + i 1 1 + i 1 1 + i 1 1 + i 0 catanhl 4 + i 0 1 + i 0 1 + i 1 1 + i 1 1 + i 1 catanhf128 - 1 + i 1 - - - cbrtf 1 - 1 1 1 cbrt 3 - 3 3 1 cbrtl 1 - 1 1 1 cbrtf128 - 1 - - - ccosf 1 + i 1 0 + i 1 1 + i 1 1 + i 1 - ccos 1 + i 1 1 + i 1 1 + i 1 1 + i 1 - ccosl 1 + i 0 1 + i 1 1 + i 1 1 + i 1 1 + i 1 ccosf128 - 1 + i 1 - - - ccoshf 1 + i 1 1 + i 1 1 + i 1 1 + i 1 - ccosh 1 + i 1 1 + i 1 1 + i 1 1 + i 1 - ccoshl 1 + i 0 0 + i 1 1 + i 1 1 + i 1 0 + i 1 ccoshf128 - 1 + i 1 - - - cexpf 1 + i 2 1 + i 2 1 + i 2 1 + i 2 - cexp 2 + i 1 2 + i 1 2 + i 1 2 + i 1 - cexpl - 1 + i 1 1 + i 1 1 + i 1 1 + i 1 cexpf128 - 1 + i 1 - - - clogf 3 + i 1 3 + i 0 3 + i 1 3 + i 1 2 + i 1 clog 3 + i 0 2 + i 1 3 + i 0 3 + i 0 3 + i 1 clogl - 2 + i 1 2 + i 1 2 + i 1 3 + i 1 clogf128 - 2 + i 1 - - - clog10f 4 + i 2 4 + i 1 4 + i 2 4 + i 2 2 + i 1 clog10 3 + i 2 3 + i 2 3 + i 2 3 + i 2 2 + i 1 clog10l 0 + i 1 2 + i 1 2 + i 2 2 + i 2 3 + i 2 clog10f128 - 2 + i 2 - - - cosf 1 - - - - cos 2 1 1 1 1 cosl 2 - 1 1 - cosf128 - 1 - - - coshf 1 - 1 1 - cosh 1 - 1 1 - coshl - - 1 1 - coshf128 - 1 - - - cpowf 5 + i 2 5 + i 2 5 + i 2 5 + i 2 3 + i 5 cpow 2 + i 2 2 + i 0 2 + i 0 2 + i 0 1 + i 0 cpowl 2 + i 2 3 + i 4 4 + i 1 4 + i 1 3 + i 1 cpowf128 - 4 + i 1 - - - csinf 1 + i 0 1 + i 1 1 + i 0 1 + i 0 - csin 1 + i 0 1 + i 0 1 + i 0 1 + i 0 - csinl - 1 + i 0 1 + i 1 1 + i 1 1 + i 0 csinf128 - 1 + i 1 - - - csinhf 1 + i 1 1 + i 1 1 + i 1 1 + i 1 - csinh 0 + i 1 1 + i 1 0 + i 1 0 + i 1 - csinhl 0 + i 1 1 + i 1 1 + i 1 1 + i 1 1 + i 0 csinhf128 - 1 + i 1 - - - csqrtf 2 + i 2 2 + i 2 2 + i 2 2 + i 2 1 + i 1 csqrt 2 + i 2 2 + i 2 2 + i 2 2 + i 2 1 + i 1 csqrtl - 2 + i 2 2 + i 2 2 + i 2 2 + i 2 csqrtf128 - 2 + i 2 - - - ctanf 1 + i 2 1 + i 1 1 + i 2 1 + i 2 1 + i 1 ctan 1 + i 2 1 + i 2 1 + i 2 1 + i 2 1 + i 1 ctanl 0 + i 1 2 + i 2 3 + i 3 3 + i 3 2 + i 2 ctanf128 - 3 + i 3 - - - ctanhf 2 + i 2 1 + i 1 2 + i 1 2 + i 1 1 + i 2 ctanh 2 + i 2 2 + i 2 2 + i 2 2 + i 2 1 + i 1 ctanhl 1 + i 0 1 + i 2 3 + i 3 3 + i 3 2 + i 2 ctanhf128 - 3 + i 3 - - - div_ldoublef - - - - - div_ldouble - - - - - div_ldoublel - - - - - div_ldoublef128- - - - - erff 1 - 1 1 1 erf 1 - 1 1 - erfl 1 - 1 1 1 erff128 - 1 - - - erfcf 2 - 2 2 1 erfc 3 - 2 2 - erfcl 1 - 2 2 2 erfcf128 - 2 - - - expf 1 1 - - - exp - - - - - expl - - 1 1 - expf128 - 1 - - - exp10f 2 - - - - exp10 6 - 2 2 - exp10l 6 - 2 2 - exp10f128 - 2 - - - exp2f 1 - - - - exp2 1 1 1 1 1 exp2l - 1 1 1 - exp2f128 - 1 - - - expm1f 1 - 1 1 - expm1 1 1 1 1 - expm1l 1 1 1 1 - expm1f128 - 1 - - - fmaf - - - - - fma - - - - - fmal - - - - - fmaf128 - - - - - fmodf - - - - - fmod - - - - - fmodl - - - - - fmodf128 - - - - - gammaf 4 1 3 3 1 gamma 4 - 3 3 - gammal - - 5 5 2 gammaf128 - - - - - hypotf 1 - - - - hypot 1 - 1 1 1 hypotl - - 1 1 1 hypotf128 - 1 - - - j0f 2 2 2 2 2 j0 2 2 2 2 1 j0l 2 2 2 2 2 j0f128 - 2 - - - j1f 2 2 2 2 2 j1 1 1 1 1 - j1l 1 1 4 4 1 j1f128 - 4 - - - jnf 5 4 4 4 2 jn 4 4 4 4 2 jnl 4 4 7 7 4 jnf128 - 7 - - - lgammaf 4 1 3 3 1 lgamma 4 - 3 3 - lgammal 1 - 5 5 2 lgammaf128 - 5 - - - logf 1 - - - - log - - - - - logl - - 1 1 - logf128 - 1 - - - log10f 2 - 2 2 - log10 2 - 2 2 - log10l 1 - 1 1 - log10f128 - 1 - - - log1pf 1 - 1 1 - log1p 1 - 1 1 - log1pl - - 2 2 - log1pf128 - 2 - - - log2f 1 - 1 1 - log2 2 - 1 1 - log2l - - 2 2 - log2f128 - 2 - - - mul_ldoublef - - - - - mul_ldouble - - - - - mul_ldoublel - - - - - mul_ldoublef128- - - - - powf 1 - - - 7 pow 1 - 1 1 1 powl - - 2 2 9 powf128 - 2 - - - sinf 1 - - - - sin 1 1 1 1 1 sinl - - 1 1 - sinf128 - 1 - - - sincosf 1 - - - - sincos 1 1 1 1 - sincosl 1 - 1 1 - sincosf128 - 1 - - - sinhf 2 - 2 2 - sinh 2 - 2 2 - sinhl - - 2 2 - sinhf128 - 2 - - - sqrtf - - - - - sqrt - - - - - sqrtl - - - - - sqrtf128 - - - - - sub_ldoublef - - - - - sub_ldouble - - - - - sub_ldoublel - - - - - sub_ldoublef128- - - - - tanf 1 - 1 1 - tan 1 - - - - tanl 1 1 1 1 - tanf128 - 1 - - - tanhf 2 - 2 2 - tanh 2 - 2 2 - tanhl - - 2 2 - tanhf128 - 2 - - - tgammaf 4 - 4 4 4 tgamma 5 - 5 5 1 tgammal 1 1 4 4 9 tgammaf128 - 4 - - - y0f 1 1 1 1 1 y0 2 2 2 2 1 y0l 2 1 3 3 1 y0f128 - 3 - - - y1f 2 2 2 2 3 y1 3 3 3 3 1 y1l 3 2 2 2 2 y1f128 - 2 - - - ynf 3 3 3 3 3 yn 3 3 3 3 2 ynl 3 3 5 5 4 ynf128 - 5 - - - Function MIPS 32-bit MIPS 64-bit MicroBlaze Nios II PowerPC acosf 1 1 1 1 1 acos - - - - - acosl - 1 - - 1 acosf128 - - - - 1 acoshf 2 2 2 2 2 acosh 2 2 2 2 2 acoshl - 2 - - 2 acoshf128 - - - - 2 add_ldoublef - - - - 1 add_ldouble - - - - 1 add_ldoublel - - - - - add_ldoublef128- - - - - asinf 1 1 1 1 1 asin - - - - - asinl - 1 - - 2 asinf128 - - - - 1 asinhf 1 1 1 1 1 asinh 1 1 1 1 1 asinhl - 3 - - 2 asinhf128 - - - - 3 atanf 1 1 1 1 1 atan - - - - 1 atanl - 1 - - 1 atanf128 - - - - 1 atan2f 1 1 1 1 1 atan2 - - - - - atan2l - 1 - - 2 atan2f128 - - - - 1 atanhf 2 2 2 2 2 atanh 2 2 2 2 2 atanhl - 3 - - 2 atanhf128 - - - - 3 cabsf - - - - - cabs 1 1 1 1 1 cabsl - 1 - - 1 cabsf128 - - - - 1 cacosf 2 + i 2 2 + i 2 2 + i 2 2 + i 2 2 + i 2 cacos 1 + i 2 1 + i 2 1 + i 2 1 + i 2 1 + i 2 cacosl - 2 + i 2 - - 1 + i 2 cacosf128 - - - - 2 + i 2 cacoshf 2 + i 2 2 + i 2 2 + i 2 2 + i 2 2 + i 2 cacosh 2 + i 1 2 + i 1 2 + i 1 2 + i 1 2 + i 1 cacoshl - 2 + i 2 - - 2 + i 1 cacoshf128 - - - - 2 + i 2 cargf 1 1 1 1 1 carg - - - - 1 cargl - 2 - - 2 cargf128 - - - - 2 casinf 1 + i 2 1 + i 2 1 + i 2 1 + i 2 1 + i 2 casin 1 + i 2 1 + i 2 1 + i 2 1 + i 2 1 + i 2 casinl - 2 + i 2 - - 1 + i 2 casinf128 - - - - 2 + i 2 casinhf 2 + i 1 2 + i 1 2 + i 1 2 + i 1 2 + i 1 casinh 2 + i 1 2 + i 1 2 + i 1 2 + i 1 2 + i 1 casinhl - 2 + i 2 - - 2 + i 1 casinhf128 - - - - 2 + i 2 catanf 1 + i 1 1 + i 1 1 + i 1 1 + i 1 1 + i 1 catan 1 + i 1 1 + i 1 1 + i 1 1 + i 1 1 + i 1 catanl - 1 + i 1 - - 3 + i 2 catanf128 - - - - 1 + i 1 catanhf 1 + i 1 1 + i 1 1 + i 1 1 + i 1 1 + i 1 catanh 1 + i 1 1 + i 1 1 + i 1 1 + i 1 1 + i 1 catanhl - 1 + i 1 - - 2 + i 3 catanhf128 - - - - 1 + i 1 cbrtf 1 1 1 1 1 cbrt 3 3 3 3 3 cbrtl - 1 - - 1 cbrtf128 - - - - 1 ccosf 1 + i 1 1 + i 1 1 + i 1 1 + i 1 1 + i 1 ccos 1 + i 1 1 + i 1 1 + i 1 1 + i 1 1 + i 1 ccosl - 1 + i 1 - - 1 + i 2 ccosf128 - - - - 1 + i 1 ccoshf 1 + i 1 1 + i 1 1 + i 1 1 + i 1 1 + i 1 ccosh 1 + i 1 1 + i 1 1 + i 1 1 + i 1 1 + i 1 ccoshl - 1 + i 1 - - 1 + i 2 ccoshf128 - - - - 1 + i 1 cexpf 1 + i 2 1 + i 2 1 + i 2 1 + i 2 1 + i 2 cexp 2 + i 1 2 + i 1 2 + i 1 2 + i 1 2 + i 1 cexpl - 1 + i 1 - - 2 + i 2 cexpf128 - - - - 1 + i 1 clogf 3 + i 1 3 + i 1 3 + i 1 3 + i 1 3 + i 1 clog 3 + i 0 3 + i 0 3 + i 0 3 + i 0 3 + i 1 clogl - 2 + i 1 - - 5 + i 2 clogf128 - - - - 2 + i 1 clog10f 4 + i 2 4 + i 2 4 + i 2 4 + i 2 4 + i 2 clog10 3 + i 2 3 + i 2 3 + i 2 3 + i 2 3 + i 2 clog10l - 2 + i 2 - - 3 + i 2 clog10f128 - - - - 2 + i 2 cosf 1 1 1 1 3 cos 1 1 - 1 1 cosl - 1 - - 4 cosf128 - - - - 1 coshf 1 1 1 1 1 cosh 1 1 1 1 1 coshl - 1 - - 3 coshf128 - - - - 1 cpowf 5 + i 2 5 + i 2 4 + i 2 5 + i 2 5 + i 2 cpow 2 + i 0 2 + i 0 2 + i 0 2 + i 0 2 + i 0 cpowl - 4 + i 1 - - 4 + i 2 cpowf128 - - - - 4 + i 1 csinf 1 + i 0 1 + i 0 1 + i 0 1 + i 0 1 + i 0 csin 1 + i 0 1 + i 0 1 + i 0 1 + i 0 1 + i 0 csinl - 1 + i 1 - - 2 + i 1 csinf128 - - - - 1 + i 1 csinhf 1 + i 1 1 + i 1 1 + i 1 1 + i 1 1 + i 1 csinh 0 + i 1 0 + i 1 0 + i 1 0 + i 1 0 + i 1 csinhl - 1 + i 1 - - 1 + i 2 csinhf128 - - - - 1 + i 1 csqrtf 2 + i 2 2 + i 2 2 + i 2 2 + i 2 2 + i 2 csqrt 2 + i 2 2 + i 2 2 + i 2 2 + i 2 2 + i 2 csqrtl - 2 + i 2 - - 1 + i 1 csqrtf128 - - - - 2 + i 2 ctanf 1 + i 2 1 + i 2 1 + i 1 1 + i 2 1 + i 2 ctan 1 + i 2 1 + i 2 1 + i 2 1 + i 2 1 + i 2 ctanl - 3 + i 3 - - 3 + i 2 ctanf128 - - - - 3 + i 3 ctanhf 2 + i 2 2 + i 2 1 + i 2 2 + i 2 2 + i 1 ctanh 2 + i 2 2 + i 2 2 + i 2 2 + i 2 2 + i 2 ctanhl - 3 + i 3 - - 3 + i 3 ctanhf128 - - - - 3 + i 3 div_ldoublef - - - - 1 div_ldouble - - - - - div_ldoublel - - - - - div_ldoublef128- - - - - erff 1 1 1 1 1 erf 1 1 1 1 1 erfl - 1 - - 1 erff128 - - - - 1 erfcf 2 2 2 2 2 erfc 3 3 3 3 2 erfcl - 2 - - 3 erfcf128 - - - - 2 expf 1 1 1 1 - exp - - - - 1 expl - 1 - - 1 expf128 - - - - 1 exp10f - - - - - exp10 2 2 2 2 2 exp10l - 2 - - 1 exp10f128 - - - - 2 exp2f 1 1 1 1 - exp2 1 1 1 1 1 exp2l - 1 - - 2 exp2f128 - - - - 1 expm1f 1 1 1 1 1 expm1 1 1 1 1 1 expm1l - 1 - - 1 expm1f128 - - - - 1 fmaf - - - - - fma - - - - - fmal - - - - 1 fmaf128 - - - - - fmodf - - - - - fmod - - - - - fmodl - - - - 1 fmodf128 - - - - - gammaf 4 4 4 4 4 gamma 4 4 4 4 3 gammal - 5 - - 3 gammaf128 - - - - - hypotf - - - - - hypot 1 1 1 1 1 hypotl - 1 - - 1 hypotf128 - - - - 1 j0f 2 2 2 2 2 j0 2 2 2 2 2 j0l - 2 - - 2 j0f128 - - - - 2 j1f 2 2 2 2 2 j1 1 1 1 1 1 j1l - 4 - - 2 j1f128 - - - - 4 jnf 4 4 4 4 4 jn 4 4 4 4 4 jnl - 7 - - 4 jnf128 - - - - 7 lgammaf 4 4 4 4 4 lgamma 4 4 4 4 3 lgammal - 5 - - 3 lgammaf128 - - - - 5 logf 1 1 1 1 1 log - - - - - logl - 1 - - 1 logf128 - - - - 1 log10f 2 2 2 2 2 log10 2 2 2 2 2 log10l - 1 - - 1 log10f128 - - - - 1 log1pf 1 1 1 1 1 log1p 1 1 1 1 1 log1pl - 2 - - 2 log1pf128 - - - - 2 log2f 1 1 1 1 1 log2 2 2 2 2 1 log2l - 2 - - 1 log2f128 - - - - 2 mul_ldoublef - - - - 1 mul_ldouble - - - - 1 mul_ldoublel - - - - - mul_ldoublef128- - - - - powf 1 1 1 3 1 pow 1 1 - 1 1 powl - 2 - - 1 powf128 - - - - 2 sinf 1 1 1 1 1 sin 1 1 - 1 1 sinl - 1 - - 1 sinf128 - - - - 1 sincosf 1 1 1 1 1 sincos 1 1 - 1 1 sincosl - 1 - - 1 sincosf128 - - - - 1 sinhf 2 2 2 2 2 sinh 2 2 2 2 2 sinhl - 2 - - 3 sinhf128 - - - - 2 sqrtf - - - - - sqrt - - - - - sqrtl - - - - 1 sqrtf128 - - - - - sub_ldoublef - - - - 1 sub_ldouble - - - - 1 sub_ldoublel - - - - - sub_ldoublef128- - - - - tanf 1 1 1 1 3 tan - - - - - tanl - 1 - - 2 tanf128 - - - - 1 tanhf 2 2 2 2 2 tanh 2 2 2 2 2 tanhl - 2 - - 1 tanhf128 - - - - 2 tgammaf 4 4 4 5 4 tgamma 5 5 5 5 5 tgammal - 4 - - 5 tgammaf128 - - - - 4 y0f 1 1 1 1 1 y0 2 2 2 2 2 y0l - 3 - - 1 y0f128 - - - - 3 y1f 2 2 2 2 2 y1 3 3 3 3 3 y1l - 2 - - 2 y1f128 - - - - 2 ynf 3 3 2 3 3 yn 3 3 3 3 3 ynl - 5 - - 2 ynf128 - - - - 5 Function PowerPC RISC-V RISC-V S/390 SH soft-float soft-float acosf 1 1 1 1 1 acos - - - - - acosl 1 1 1 1 - acosf128 - - - - - acoshf 2 2 2 2 2 acosh 2 2 2 2 2 acoshl 1 2 2 2 - acoshf128 - - - - - add_ldoublef 1 - - - - add_ldouble 1 - - - - add_ldoublel - - - - - add_ldoublef128- - - - - asinf 1 1 1 1 1 asin - - - - - asinl 2 1 1 1 - asinf128 - - - - - asinhf 1 1 1 1 1 asinh 1 1 1 1 1 asinhl 2 3 3 3 - asinhf128 - - - - - atanf 1 1 1 1 1 atan - - - - - atanl 1 1 1 1 - atanf128 - - - - - atan2f 1 1 1 1 1 atan2 - - - - - atan2l 2 1 1 1 - atan2f128 - - - - - atanhf 2 2 2 2 2 atanh 2 2 2 2 2 atanhl 2 3 3 3 - atanhf128 - - - - - cabsf - - - - - cabs 1 1 1 1 1 cabsl 1 1 1 1 - cabsf128 - - - - - cacosf 2 + i 2 2 + i 2 2 + i 2 2 + i 2 2 + i 2 cacos 1 + i 2 1 + i 2 1 + i 2 1 + i 2 1 + i 2 cacosl 2 + i 1 2 + i 2 2 + i 2 2 + i 2 - cacosf128 - - - - - cacoshf 2 + i 2 2 + i 2 2 + i 2 2 + i 2 2 + i 2 cacosh 2 + i 1 2 + i 1 2 + i 1 2 + i 1 2 + i 1 cacoshl 1 + i 2 2 + i 2 2 + i 2 2 + i 2 - cacoshf128 - - - - - cargf 1 1 1 1 1 carg - - - - - cargl 2 2 2 2 - cargf128 - - - - - casinf 1 + i 2 1 + i 2 1 + i 2 1 + i 2 1 + i 2 casin 1 + i 2 1 + i 2 1 + i 2 1 + i 2 1 + i 2 casinl 2 + i 1 2 + i 2 2 + i 2 2 + i 2 - casinf128 - - - - - casinhf 2 + i 1 2 + i 1 2 + i 1 2 + i 1 2 + i 1 casinh 2 + i 1 2 + i 1 2 + i 1 2 + i 1 2 + i 1 casinhl 1 + i 2 2 + i 2 2 + i 2 2 + i 2 - casinhf128 - - - - - catanf 1 + i 1 1 + i 1 1 + i 1 1 + i 1 1 + i 1 catan 1 + i 1 1 + i 1 1 + i 1 1 + i 1 1 + i 1 catanl 3 + i 2 1 + i 1 1 + i 1 1 + i 1 - catanf128 - - - - - catanhf 1 + i 1 1 + i 1 1 + i 1 1 + i 1 1 + i 1 catanh 1 + i 1 1 + i 1 1 + i 1 1 + i 1 1 + i 1 catanhl 2 + i 3 1 + i 1 1 + i 1 1 + i 1 - catanhf128 - - - - - cbrtf 1 1 1 1 1 cbrt 3 3 3 3 3 cbrtl 1 1 1 1 - cbrtf128 - - - - - ccosf 1 + i 1 1 + i 1 1 + i 1 1 + i 1 1 + i 1 ccos 1 + i 1 1 + i 1 1 + i 1 1 + i 1 1 + i 1 ccosl 1 + i 2 1 + i 1 1 + i 1 1 + i 1 - ccosf128 - - - - - ccoshf 1 + i 1 1 + i 1 1 + i 1 1 + i 1 1 + i 1 ccosh 1 + i 1 1 + i 1 1 + i 1 1 + i 1 1 + i 1 ccoshl 1 + i 2 1 + i 1 1 + i 1 1 + i 1 - ccoshf128 - - - - - cexpf 1 + i 2 1 + i 2 1 + i 2 1 + i 2 1 + i 2 cexp 2 + i 1 2 + i 1 2 + i 1 2 + i 1 2 + i 1 cexpl 1 + i 1 1 + i 1 1 + i 1 1 + i 1 - cexpf128 - - - - - clogf 3 + i 1 3 + i 1 3 + i 1 3 + i 1 3 + i 1 clog 3 + i 0 3 + i 0 3 + i 0 3 + i 0 3 + i 0 clogl 2 + i 2 2 + i 1 2 + i 1 2 + i 1 - clogf128 - - - - - clog10f 4 + i 2 4 + i 2 4 + i 2 4 + i 2 4 + i 2 clog10 3 + i 2 3 + i 2 3 + i 2 3 + i 2 3 + i 2 clog10l 3 + i 2 2 + i 2 2 + i 2 2 + i 2 - clog10f128 - - - - - cosf 1 - - - 1 cos 1 1 - 1 1 cosl 4 1 1 1 - cosf128 - - - - - coshf 1 1 1 1 1 cosh 1 1 1 1 1 coshl 3 1 1 1 - coshf128 - - - - - cpowf 5 + i 2 5 + i 2 5 + i 2 5 + i 2 5 + i 2 cpow 2 + i 0 2 + i 0 2 + i 0 2 + i 0 2 + i 0 cpowl 4 + i 1 4 + i 1 4 + i 1 4 + i 1 - cpowf128 - - - - - csinf 1 + i 0 1 + i 0 1 + i 0 1 + i 0 1 + i 0 csin 1 + i 0 1 + i 0 1 + i 0 1 + i 0 1 + i 0 csinl 2 + i 1 1 + i 1 1 + i 1 1 + i 1 - csinf128 - - - - - csinhf 1 + i 1 1 + i 1 1 + i 1 1 + i 1 1 + i 1 csinh 0 + i 1 0 + i 1 0 + i 1 0 + i 1 0 + i 1 csinhl 1 + i 2 1 + i 1 1 + i 1 1 + i 1 - csinhf128 - - - - - csqrtf 2 + i 2 2 + i 2 2 + i 2 2 + i 2 2 + i 2 csqrt 2 + i 2 2 + i 2 2 + i 2 2 + i 2 2 + i 2 csqrtl 1 + i 1 2 + i 2 2 + i 2 2 + i 2 - csqrtf128 - - - - - ctanf 1 + i 2 1 + i 2 1 + i 2 1 + i 2 1 + i 2 ctan 1 + i 2 1 + i 2 1 + i 2 1 + i 2 1 + i 2 ctanl 3 + i 2 3 + i 3 3 + i 3 3 + i 3 - ctanf128 - - - - - ctanhf 2 + i 2 2 + i 1 2 + i 2 2 + i 1 2 + i 2 ctanh 2 + i 2 2 + i 2 2 + i 2 2 + i 2 2 + i 2 ctanhl 2 + i 3 3 + i 3 3 + i 3 3 + i 3 - ctanhf128 - - - - - div_ldoublef 1 - - - - div_ldouble - - - - - div_ldoublel - - - - - div_ldoublef128- - - - - erff 1 1 1 1 1 erf 1 1 1 1 1 erfl 1 1 1 1 - erff128 - - - - - erfcf 2 2 2 2 2 erfc 3 2 3 2 3 erfcl 3 2 2 2 - erfcf128 - - - - - expf 1 - - - - exp - - - - - expl 1 1 1 1 - expf128 - - - - - exp10f - - - - - exp10 2 2 2 2 2 exp10l 1 2 2 2 - exp10f128 - - - - - exp2f 1 - - - - exp2 1 1 1 1 1 exp2l 1 1 1 1 - exp2f128 - - - - - expm1f 1 1 1 1 1 expm1 1 1 1 1 1 expm1l 1 1 1 1 - expm1f128 - - - - - fmaf - - - - - fma - - - - - fmal 1 - - - - fmaf128 - - - - - fmodf - - - - - fmod - - - - - fmodl 1 - - - - fmodf128 - - - - - gammaf 4 3 3 3 3 gamma 4 3 4 3 4 gammal 3 5 5 5 - gammaf128 - - - - - hypotf - - - - - hypot 1 1 1 1 1 hypotl 1 1 1 1 - hypotf128 - - - - - j0f 2 2 2 2 2 j0 2 2 2 2 2 j0l 2 2 2 2 - j0f128 - - - - - j1f 2 2 2 2 2 j1 1 1 1 1 1 j1l 1 4 4 4 - j1f128 - - - - - jnf 4 4 4 4 4 jn 4 4 4 4 4 jnl 4 7 7 7 - jnf128 - - - - - lgammaf 4 3 3 3 3 lgamma 4 3 4 3 4 lgammal 3 5 5 5 - lgammaf128 - - - - - logf 1 - - - 1 log - - - - - logl 1 1 1 1 - logf128 - - - - - log10f 2 2 2 2 2 log10 2 2 2 2 2 log10l 1 1 1 1 - log10f128 - - - - - log1pf 1 1 1 1 1 log1p 1 1 1 1 1 log1pl 2 2 2 2 - log1pf128 - - - - - log2f 1 1 1 1 1 log2 2 1 2 1 2 log2l 1 2 2 2 - log2f128 - - - - - mul_ldoublef 1 - - - - mul_ldouble 1 - - - - mul_ldoublel - - - - - mul_ldoublef128- - - - - powf 1 - - - 1 pow 1 1 - 1 1 powl 1 2 2 2 - powf128 - - - - - sinf 1 - - - 1 sin 1 1 - 1 1 sinl 1 1 1 1 - sinf128 - - - - - sincosf 1 - - - 1 sincos 1 1 - 1 1 sincosl 1 1 1 1 - sincosf128 - - - - - sinhf 2 2 2 2 2 sinh 2 2 2 2 2 sinhl 3 2 2 2 - sinhf128 - - - - - sqrtf - - - - - sqrt - - - - - sqrtl 1 - - - - sqrtf128 - - - - - sub_ldoublef 1 - - - - sub_ldouble 1 - - - - sub_ldoublel - - - - - sub_ldoublef128- - - - - tanf 1 1 1 1 1 tan - - - - - tanl 2 1 1 1 - tanf128 - - - - - tanhf 2 2 2 2 2 tanh 2 2 2 2 2 tanhl 1 2 2 2 - tanhf128 - - - - - tgammaf 4 4 4 4 4 tgamma 5 5 5 5 5 tgammal 3 4 4 4 - tgammaf128 - - - - - y0f 1 1 1 1 1 y0 2 2 2 2 2 y0l 1 3 3 3 - y0f128 - - - - - y1f 2 2 2 2 2 y1 3 3 3 3 3 y1l 2 2 2 2 - y1f128 - - - - - ynf 3 3 3 3 3 yn 3 3 3 3 3 ynl 2 5 5 5 - ynf128 - - - - - Function Sparc i686 ix86 x86_64 acosf 1 - - 1 acos - 1 1 - acosl 1 1 1 1 acosf128 - 1 1 1 acoshf 2 - - 2 acosh 2 1 1 2 acoshl 2 2 2 2 acoshf128 - 2 2 2 add_ldoublef - - - - add_ldouble - - - - add_ldoublel - - - - add_ldoublef128- - - - asinf 1 - - 1 asin - 1 1 - asinl 1 1 1 1 asinf128 - 1 1 1 asinhf 1 - - 1 asinh 1 1 1 1 asinhl 3 3 3 3 asinhf128 - 3 3 3 atanf 1 - - 1 atan - 1 1 - atanl 1 1 1 1 atanf128 - 1 1 1 atan2f 1 - - 1 atan2 - 1 1 - atan2l 1 1 1 1 atan2f128 - 1 1 1 atanhf 2 - - 2 atanh 2 1 1 2 atanhl 3 3 3 3 atanhf128 - 3 3 3 cabsf - - - - cabs 1 1 1 1 cabsl 1 1 1 1 cabsf128 - 1 1 1 cacosf 2 + i 2 2 + i 2 2 + i 2 2 + i 2 cacos 1 + i 2 1 + i 2 1 + i 2 1 + i 2 cacosl 2 + i 2 1 + i 2 1 + i 2 1 + i 2 cacosf128 - 2 + i 2 2 + i 2 2 + i 2 cacoshf 2 + i 2 2 + i 2 2 + i 2 2 + i 2 cacosh 2 + i 1 2 + i 1 2 + i 1 2 + i 1 cacoshl 2 + i 2 2 + i 1 2 + i 1 2 + i 1 cacoshf128 - 2 + i 2 2 + i 2 2 + i 2 cargf 1 - - 1 carg - 1 1 - cargl 2 1 1 1 cargf128 - 2 2 2 casinf 1 + i 2 1 + i 2 1 + i 2 1 + i 2 casin 1 + i 2 1 + i 2 1 + i 2 1 + i 2 casinl 2 + i 2 1 + i 2 1 + i 2 1 + i 2 casinf128 - 2 + i 2 2 + i 2 2 + i 2 casinhf 2 + i 1 2 + i 1 2 + i 1 2 + i 1 casinh 2 + i 1 2 + i 1 2 + i 1 2 + i 1 casinhl 2 + i 2 2 + i 1 2 + i 1 2 + i 1 casinhf128 - 2 + i 2 2 + i 2 2 + i 2 catanf 1 + i 1 0 + i 1 0 + i 1 1 + i 1 catan 1 + i 1 1 + i 1 1 + i 1 1 + i 1 catanl 1 + i 1 1 + i 1 1 + i 1 1 + i 1 catanf128 - 1 + i 1 1 + i 1 1 + i 1 catanhf 1 + i 1 1 + i 0 1 + i 0 1 + i 1 catanh 1 + i 1 1 + i 1 1 + i 1 1 + i 1 catanhl 1 + i 1 1 + i 1 1 + i 1 1 + i 1 catanhf128 - 1 + i 1 1 + i 1 1 + i 1 cbrtf 1 1 1 1 cbrt 3 1 1 3 cbrtl 1 3 3 1 cbrtf128 - 1 1 1 ccosf 1 + i 1 1 + i 1 1 + i 1 1 + i 1 ccos 1 + i 1 1 + i 1 1 + i 1 1 + i 1 ccosl 1 + i 1 1 + i 1 1 + i 1 1 + i 1 ccosf128 - 1 + i 1 1 + i 1 1 + i 1 ccoshf 1 + i 1 1 + i 1 1 + i 1 1 + i 1 ccosh 1 + i 1 1 + i 1 1 + i 1 1 + i 1 ccoshl 1 + i 1 1 + i 1 1 + i 1 1 + i 1 ccoshf128 - 1 + i 1 1 + i 1 1 + i 1 cexpf 1 + i 2 1 + i 2 1 + i 2 1 + i 2 cexp 2 + i 1 2 + i 1 2 + i 1 2 + i 1 cexpl 1 + i 1 1 + i 1 1 + i 1 1 + i 1 cexpf128 - 1 + i 1 1 + i 1 1 + i 1 clogf 3 + i 1 3 + i 0 3 + i 0 3 + i 1 clog 3 + i 0 2 + i 1 2 + i 1 3 + i 0 clogl 4 + i 1 3 + i 1 3 + i 1 3 + i 1 clogf128 - 2 + i 1 2 + i 1 2 + i 1 clog10f 4 + i 2 4 + i 1 4 + i 1 4 + i 2 clog10 3 + i 2 3 + i 2 3 + i 2 3 + i 2 clog10l 4 + i 2 4 + i 2 4 + i 2 4 + i 2 clog10f128 - 2 + i 2 2 + i 2 2 + i 2 cosf 1 - 1 - cos 1 1 1 1 cosl 1 1 1 1 cosf128 - 1 1 1 coshf 1 1 1 1 cosh 1 1 1 1 coshl 1 2 2 2 coshf128 - 1 1 1 cpowf 5 + i 2 5 + i 2 5 + i 2 5 + i 2 cpow 2 + i 0 2 + i 1 2 + i 0 2 + i 0 cpowl 4 + i 1 3 + i 4 3 + i 4 3 + i 4 cpowf128 - 4 + i 1 4 + i 1 4 + i 1 csinf 1 + i 0 1 + i 1 1 + i 1 1 + i 0 csin 1 + i 0 1 + i 1 1 + i 0 1 + i 0 csinl 1 + i 1 1 + i 0 1 + i 0 1 + i 0 csinf128 - 1 + i 1 1 + i 1 1 + i 1 csinhf 1 + i 1 1 + i 1 1 + i 1 1 + i 1 csinh 0 + i 1 1 + i 1 0 + i 1 0 + i 1 csinhl 1 + i 1 1 + i 1 1 + i 1 1 + i 1 csinhf128 - 1 + i 1 1 + i 1 1 + i 1 csqrtf 2 + i 2 2 + i 2 2 + i 2 2 + i 2 csqrt 2 + i 2 2 + i 2 2 + i 2 2 + i 2 csqrtl 2 + i 2 2 + i 2 2 + i 2 2 + i 2 csqrtf128 - 2 + i 2 2 + i 2 2 + i 2 ctanf 1 + i 2 1 + i 2 1 + i 2 1 + i 2 ctan 1 + i 2 1 + i 2 1 + i 2 1 + i 2 ctanl 3 + i 3 2 + i 1 2 + i 1 2 + i 1 ctanf128 - 3 + i 3 3 + i 3 3 + i 3 ctanhf 2 + i 2 2 + i 2 2 + i 2 2 + i 2 ctanh 2 + i 2 2 + i 2 2 + i 2 2 + i 2 ctanhl 3 + i 3 1 + i 2 1 + i 2 1 + i 2 ctanhf128 - 3 + i 3 3 + i 3 3 + i 3 div_ldoublef - - - - div_ldouble - - - - div_ldoublel - - - - div_ldoublef128- - - - erff 1 1 1 1 erf 1 1 1 1 erfl 1 1 1 1 erff128 - 1 1 1 erfcf 2 2 2 2 erfc 3 3 3 3 erfcl 2 3 3 3 erfcf128 - 2 2 2 expf 1 - - - exp - 1 1 - expl 1 1 1 1 expf128 - 1 1 1 exp10f - - - - exp10 2 1 1 2 exp10l 2 1 1 1 exp10f128 - 2 2 2 exp2f 1 - - 1 exp2 1 1 1 1 exp2l 1 1 1 1 exp2f128 - 1 1 1 expm1f 1 - - 1 expm1 1 1 1 1 expm1l 1 2 2 2 expm1f128 - 1 1 1 fmaf - - - - fma - - - - fmal - - - - fmaf128 - - - - fmodf - - - - fmod - - - - fmodl - - - - fmodf128 - - - - gammaf 4 3 3 4 gamma 4 4 4 4 gammal 5 4 4 4 gammaf128 - - - - hypotf - - - - hypot 1 1 1 1 hypotl 1 1 1 1 hypotf128 - 1 1 1 j0f 2 2 2 2 j0 2 2 2 2 j0l 2 2 2 2 j0f128 - 2 2 2 j1f 2 2 2 2 j1 1 2 2 1 j1l 4 1 1 1 j1f128 - 4 4 4 jnf 4 4 4 4 jn 4 4 4 4 jnl 7 4 4 4 jnf128 - 7 7 7 lgammaf 4 3 3 4 lgamma 4 4 4 4 lgammal 5 4 4 4 lgammaf128 - 5 5 5 logf 1 - - 1 log - 1 1 - logl 1 1 1 1 logf128 - 1 1 1 log10f 2 - - 2 log10 2 1 1 2 log10l 1 1 1 1 log10f128 - 1 1 1 log1pf 1 - - 1 log1p 1 1 1 1 log1pl 2 2 2 2 log1pf128 - 2 2 2 log2f 1 1 1 1 log2 2 1 1 2 log2l 2 1 1 1 log2f128 - 2 2 2 mul_ldoublef - - - - mul_ldouble - - - - mul_ldoublel - - - - mul_ldoublef128- - - - powf 3 - - 1 pow 1 1 1 1 powl 2 1 1 1 powf128 - 2 2 2 sinf 1 - 1 - sin 1 1 1 1 sinl 1 1 1 1 sinf128 - 1 1 1 sincosf 1 - 1 - sincos 1 1 1 1 sincosl 1 1 1 1 sincosf128 - 1 1 1 sinhf 2 2 2 2 sinh 2 2 2 2 sinhl 2 2 2 2 sinhf128 - 2 2 2 sqrtf - - - - sqrt - - - - sqrtl - - - - sqrtf128 - - - - sub_ldoublef - - - - sub_ldouble - - - - sub_ldoublel - - - - sub_ldoublef128- - - - tanf 1 1 1 1 tan - - - - tanl 1 2 2 2 tanf128 - 1 1 1 tanhf 2 2 2 2 tanh 2 2 2 2 tanhl 2 3 3 3 tanhf128 - 2 2 2 tgammaf 5 4 4 5 tgamma 5 5 5 5 tgammal 4 5 5 5 tgammaf128 - 4 4 4 y0f 1 1 1 1 y0 2 2 2 2 y0l 3 1 1 1 y0f128 - 3 3 3 y1f 2 2 2 2 y1 3 3 3 3 y1l 2 2 2 2 y1f128 - 2 2 2 ynf 3 3 3 3 yn 3 3 3 3 ynl 5 4 4 4 ynf128 - 5 5 5