fish-shell/src/wutil.cpp
Fabian Homborg 65883e0e40 Restyle
Mostly line breaks, one instance of tabs!

For some reason clang-format insists on two spaces before a same-line comment?

(I continue to be unimpressed with super-strict line length limits,
but I continue to believe in automatic styling, so it is what it is)

[ci skip]
2020-02-17 14:14:05 +01:00

828 lines
26 KiB
C++

// Wide character equivalents of various standard unix functions.
#define FISH_NO_ISW_WRAPPERS
#include "config.h"
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <libgen.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <cstring>
#if defined(__linux__)
#include <sys/statfs.h>
#endif
#include <sys/mount.h>
#include <sys/statvfs.h>
#include <sys/types.h>
#include <unistd.h>
#include <wctype.h>
#include <atomic>
#include <cwchar>
#include <string>
#include <unordered_map>
#include "common.h"
#include "fallback.h" // IWYU pragma: keep
#include "flog.h"
#include "wutil.h" // IWYU pragma: keep
using cstring = std::string;
const file_id_t kInvalidFileID = {static_cast<dev_t>(-1LL),
static_cast<ino_t>(-1LL),
static_cast<uint64_t>(-1LL),
-1,
-1,
-1,
-1};
/// Map used as cache by wgettext.
static owning_lock<std::unordered_map<wcstring, wcstring>> wgettext_map;
bool wreaddir_resolving(DIR *dir, const wcstring &dir_path, wcstring &out_name, bool *out_is_dir) {
struct dirent *result = readdir(dir);
if (!result) {
out_name.clear();
return false;
}
out_name = str2wcstring(result->d_name);
if (!out_is_dir) {
return true;
}
// The caller cares if this is a directory, so check.
bool is_dir = false;
// We may be able to skip stat, if the readdir can tell us the file type directly.
bool check_with_stat = true;
#ifdef HAVE_STRUCT_DIRENT_D_TYPE
if (result->d_type == DT_DIR) {
// Known directory.
is_dir = true;
check_with_stat = false;
} else if (result->d_type == DT_LNK || result->d_type == DT_UNKNOWN) {
// We want to treat symlinks to directories as directories. Use stat to resolve it.
check_with_stat = true;
} else {
// Regular file.
is_dir = false;
check_with_stat = false;
}
#endif // HAVE_STRUCT_DIRENT_D_TYPE
if (check_with_stat) {
// We couldn't determine the file type from the dirent; check by stat'ing it.
cstring fullpath = wcs2string(dir_path);
fullpath.push_back('/');
fullpath.append(result->d_name);
struct stat buf;
if (stat(fullpath.c_str(), &buf) != 0) {
is_dir = false;
} else {
is_dir = static_cast<bool>(S_ISDIR(buf.st_mode));
}
}
*out_is_dir = is_dir;
return true;
}
bool wreaddir(DIR *dir, wcstring &out_name) {
struct dirent *result = readdir(dir);
if (!result) {
out_name.clear();
return false;
}
out_name = str2wcstring(result->d_name);
return true;
}
bool wreaddir_for_dirs(DIR *dir, wcstring *out_name) {
struct dirent *result = nullptr;
while (!result) {
result = readdir(dir);
if (!result) break;
#if HAVE_STRUCT_DIRENT_D_TYPE
switch (result->d_type) {
case DT_DIR:
case DT_LNK:
case DT_UNKNOWN: {
break; // these may be directories
}
default: {
break; // nothing else can
}
}
#else
// We can't determine if it's a directory or not, so just return it.
break;
#endif
}
if (result && out_name) {
*out_name = str2wcstring(result->d_name);
}
return result != nullptr;
}
wcstring wgetcwd() {
char cwd[PATH_MAX];
char *res = getcwd(cwd, sizeof(cwd));
if (res) {
return str2wcstring(res);
}
FLOGF(error, _(L"getcwd() failed with errno %d/%s"), errno, std::strerror(errno));
return wcstring();
}
int set_cloexec(int fd, bool should_set) {
// Note we don't want to overwrite existing flags like O_NONBLOCK which may be set. So fetch the
// existing flags and modify them.
int flags = fcntl(fd, F_GETFD, 0);
if (flags < 0) {
return -1;
}
int new_flags = flags;
if (should_set) {
new_flags |= FD_CLOEXEC;
} else {
new_flags &= ~FD_CLOEXEC;
}
if (flags == new_flags) {
return 0;
} else {
return fcntl(fd, F_SETFD, new_flags);
}
}
int open_cloexec(const std::string &path, int flags, mode_t mode) {
return open_cloexec(path.c_str(), flags, mode);
}
int open_cloexec(const char *path, int flags, mode_t mode) {
ASSERT_IS_NOT_FORKED_CHILD();
int fd;
#ifdef O_CLOEXEC
// Prefer to use O_CLOEXEC. It has to both be defined and nonzero.
fd = open(path, flags | O_CLOEXEC, mode);
#else
fd = open(path, flags, mode);
if (fd >= 0 && !set_cloexec(fd)) {
exec_close(fd);
fd = -1;
}
#endif
return fd;
}
int wopen_cloexec(const wcstring &pathname, int flags, mode_t mode) {
cstring tmp = wcs2string(pathname);
return open_cloexec(tmp, flags, mode);
}
DIR *wopendir(const wcstring &name) {
const cstring tmp = wcs2string(name);
return opendir(tmp.c_str());
}
dir_t::dir_t(const wcstring &path) {
const cstring tmp = wcs2string(path);
this->dir = opendir(tmp.c_str());
}
dir_t::~dir_t() {
if (this->dir != nullptr) {
closedir(this->dir);
this->dir = nullptr;
}
}
bool dir_t::valid() const { return this->dir != nullptr; }
bool dir_t::read(wcstring &name) { return wreaddir(this->dir, name); }
int wstat(const wcstring &file_name, struct stat *buf) {
const cstring tmp = wcs2string(file_name);
return stat(tmp.c_str(), buf);
}
int lwstat(const wcstring &file_name, struct stat *buf) {
const cstring tmp = wcs2string(file_name);
return lstat(tmp.c_str(), buf);
}
int waccess(const wcstring &file_name, int mode) {
const cstring tmp = wcs2string(file_name);
return access(tmp.c_str(), mode);
}
int wunlink(const wcstring &file_name) {
const cstring tmp = wcs2string(file_name);
return unlink(tmp.c_str());
}
void wperror(const wchar_t *s) {
int e = errno;
if (s[0] != L'\0') {
std::fwprintf(stderr, L"%ls: ", s);
}
std::fwprintf(stderr, L"%s\n", std::strerror(e));
}
int make_fd_nonblocking(int fd) {
int flags = fcntl(fd, F_GETFL, 0);
int err = 0;
bool nonblocking = flags & O_NONBLOCK;
if (!nonblocking) {
err = fcntl(fd, F_SETFL, flags | O_NONBLOCK);
}
return err == -1 ? errno : 0;
}
int make_fd_blocking(int fd) {
int flags = fcntl(fd, F_GETFL, 0);
int err = 0;
bool nonblocking = flags & O_NONBLOCK;
if (nonblocking) {
err = fcntl(fd, F_SETFL, flags & ~O_NONBLOCK);
}
return err == -1 ? errno : 0;
}
int fd_check_is_remote(int fd) {
#if defined(__linux__)
struct statfs buf {};
if (fstatfs(fd, &buf) < 0) {
return -1;
}
// Linux has constants for these like NFS_SUPER_MAGIC, SMB_SUPER_MAGIC, CIFS_MAGIC_NUMBER but
// these are in varying headers. Simply hard code them.
// NOTE: The cast is necessary for 32-bit systems because of the 4-byte CIFS_MAGIC_NUMBER
switch ((unsigned int)buf.f_type) {
case 0x6969: // NFS_SUPER_MAGIC
case 0x517B: // SMB_SUPER_MAGIC
case 0xFF534D42u: // CIFS_MAGIC_NUMBER
return 1;
default:
// Other FSes are assumed local.
return 0;
}
#elif defined(ST_LOCAL)
// ST_LOCAL is a flag to statvfs, which is itself standardized.
// In practice the only system to use this path is NetBSD.
struct statvfs buf {};
if (fstatvfs(fd, &buf) < 0) return -1;
return (buf.f_flag & ST_LOCAL) ? 0 : 1;
#elif defined(MNT_LOCAL)
struct statfs buf {};
if (fstatfs(fd, &buf) < 0) return -1;
return (buf.f_flags & MNT_LOCAL) ? 0 : 1;
#else
return -1;
#endif
}
static inline void safe_append(char *buffer, const char *s, size_t buffsize) {
std::strncat(buffer, s, buffsize - std::strlen(buffer) - 1);
}
// In general, strerror is not async-safe, and therefore we cannot use it directly. So instead we
// have to grub through sys_nerr and sys_errlist directly On GNU toolchain, this will produce a
// deprecation warning from the linker (!!), which appears impossible to suppress!
const char *safe_strerror(int err) {
#if defined(__UCLIBC__)
// uClibc does not have sys_errlist, however, its strerror is believed to be async-safe.
// See issue #808.
return std::strerror(err);
#elif defined(HAVE__SYS__ERRS) || defined(HAVE_SYS_ERRLIST)
#ifdef HAVE_SYS_ERRLIST
if (err >= 0 && err < sys_nerr && sys_errlist[err] != nullptr) {
return sys_errlist[err];
}
#elif defined(HAVE__SYS__ERRS)
extern const char _sys_errs[];
extern const int _sys_index[];
extern int _sys_num_err;
if (err >= 0 && err < _sys_num_err) {
return &_sys_errs[_sys_index[err]];
}
#endif // either HAVE__SYS__ERRS or HAVE_SYS_ERRLIST
#endif // defined(HAVE__SYS__ERRS) || defined(HAVE_SYS_ERRLIST)
int saved_err = errno;
static char buff[384]; // use a shared buffer for this case
char errnum_buff[64];
format_long_safe(errnum_buff, err);
buff[0] = '\0';
safe_append(buff, "unknown error (errno was ", sizeof buff);
safe_append(buff, errnum_buff, sizeof buff);
safe_append(buff, ")", sizeof buff);
errno = saved_err;
return buff;
}
void safe_perror(const char *message) {
// Note we cannot use strerror, because on Linux it uses gettext, which is not safe.
int err = errno;
char buff[384];
buff[0] = '\0';
if (message) {
safe_append(buff, message, sizeof buff);
safe_append(buff, ": ", sizeof buff);
}
safe_append(buff, safe_strerror(err), sizeof buff);
safe_append(buff, "\n", sizeof buff);
ignore_result(write(STDERR_FILENO, buff, std::strlen(buff)));
errno = err;
}
/// Wide character realpath. The last path component does not need to be valid. If an error occurs,
/// wrealpath() returns none() and errno is likely set.
maybe_t<wcstring> wrealpath(const wcstring &pathname) {
if (pathname.empty()) return none();
cstring real_path;
cstring narrow_path = wcs2string(pathname);
// Strip trailing slashes. This is treats "/a//" as equivalent to "/a" if /a is a non-directory.
while (narrow_path.size() > 1 && narrow_path.at(narrow_path.size() - 1) == '/') {
narrow_path.erase(narrow_path.size() - 1, 1);
}
char tmpbuf[PATH_MAX];
char *narrow_res = realpath(narrow_path.c_str(), tmpbuf);
if (narrow_res) {
real_path.append(narrow_res);
} else {
// Check if everything up to the last path component is valid.
size_t pathsep_idx = narrow_path.rfind('/');
if (pathsep_idx == 0) {
// If the only pathsep is the first character then it's an absolute path with a
// single path component and thus doesn't need conversion.
real_path = narrow_path;
} else {
// Only call realpath() on the portion up to the last component.
errno = 0;
if (pathsep_idx == cstring::npos) {
// If there is no "/", this is a file in $PWD, so give the realpath to that.
narrow_res = realpath(".", tmpbuf);
} else {
errno = 0;
// Only call realpath() on the portion up to the last component.
narrow_res = realpath(narrow_path.substr(0, pathsep_idx).c_str(), tmpbuf);
}
if (!narrow_res) return none();
pathsep_idx++;
real_path.append(narrow_res);
// This test is to deal with cases such as /../../x => //x.
if (real_path.size() > 1) real_path.append("/");
real_path.append(narrow_path.substr(pathsep_idx, cstring::npos));
}
}
return str2wcstring(real_path);
}
wcstring normalize_path(const wcstring &path) {
// Count the leading slashes.
const wchar_t sep = L'/';
size_t leading_slashes = 0;
for (wchar_t c : path) {
if (c != sep) break;
leading_slashes++;
}
wcstring_list_t comps = split_string(path, sep);
wcstring_list_t new_comps;
for (wcstring &comp : comps) {
if (comp.empty() || comp == L".") {
continue;
} else if (comp != L"..") {
new_comps.push_back(std::move(comp));
} else if (!new_comps.empty() && new_comps.back() != L"..") {
// '..' with a real path component, drop that path component.
new_comps.pop_back();
} else if (leading_slashes == 0) {
// We underflowed the .. and are a relative (not absolute) path.
new_comps.push_back(L"..");
}
}
wcstring result = join_strings(new_comps, sep);
// Prepend one or two leading slashes.
// Two slashes are preserved. Three+ slashes are collapsed to one. (!)
result.insert(0, leading_slashes > 2 ? 1 : leading_slashes, sep);
// Ensure ./ normalizes to . and not empty.
if (result.empty()) result.push_back(L'.');
return result;
}
wcstring path_normalize_for_cd(const wcstring &wd, const wcstring &path) {
// Fast paths.
const wchar_t sep = L'/';
assert(!wd.empty() && wd.front() == sep && wd.back() == sep &&
"Invalid working directory, it must start and end with /");
if (path.empty()) {
return wd;
} else if (path.front() == sep) {
return path;
} else if (path.front() != L'.') {
return wd + path;
}
// Split our strings by the sep.
wcstring_list_t wd_comps = split_string(wd, sep);
wcstring_list_t path_comps = split_string(path, sep);
// Remove empty segments from wd_comps.
// In particular this removes the leading and trailing empties.
wd_comps.erase(std::remove(wd_comps.begin(), wd_comps.end(), L""), wd_comps.end());
// Erase leading . and .. components from path_comps, popping from wd_comps as we go.
size_t erase_count = 0;
for (const wcstring &comp : path_comps) {
bool erase_it = false;
if (comp.empty() || comp == L".") {
erase_it = true;
} else if (comp == L".." && !wd_comps.empty()) {
erase_it = true;
wd_comps.pop_back();
}
if (erase_it) {
erase_count++;
} else {
break;
}
}
// Append un-erased elements to wd_comps and join them, then prepend the leading /.
std::move(path_comps.begin() + erase_count, path_comps.end(), std::back_inserter(wd_comps));
wcstring result = join_strings(wd_comps, sep);
result.insert(0, 1, L'/');
return result;
}
wcstring wdirname(const wcstring &path) {
char *tmp = wcs2str(path);
char *narrow_res = dirname(tmp);
wcstring result = format_string(L"%s", narrow_res);
free(tmp);
return result;
}
wcstring wbasename(const wcstring &path) {
char *tmp = wcs2str(path);
char *narrow_res = basename(tmp);
wcstring result = format_string(L"%s", narrow_res);
free(tmp);
return result;
}
// Really init wgettext.
static void wgettext_really_init() {
fish_bindtextdomain(PACKAGE_NAME, LOCALEDIR);
fish_textdomain(PACKAGE_NAME);
}
/// For wgettext: Internal init function. Automatically called when a translation is first
/// requested.
static void wgettext_init_if_necessary() {
static std::once_flag s_wgettext_init{};
std::call_once(s_wgettext_init, wgettext_really_init);
}
const wcstring &wgettext(const wchar_t *in) {
// Preserve errno across this since this is often used in printing error messages.
int err = errno;
wcstring key = in;
wgettext_init_if_necessary();
auto wmap = wgettext_map.acquire();
wcstring &val = (*wmap)[key];
if (val.empty()) {
cstring mbs_in = wcs2string(key);
char *out = fish_gettext(mbs_in.c_str());
val = format_string(L"%s", out);
}
errno = err;
// The returned string is stored in the map.
// TODO: If we want to shrink the map, this would be a problem.
return val;
}
int wmkdir(const wcstring &name, int mode) {
cstring name_narrow = wcs2string(name);
return mkdir(name_narrow.c_str(), mode);
}
int wrename(const wcstring &old, const wcstring &newv) {
cstring old_narrow = wcs2string(old);
cstring new_narrow = wcs2string(newv);
return rename(old_narrow.c_str(), new_narrow.c_str());
}
/// Return one if the code point is in a Unicode private use area.
int fish_is_pua(wint_t wc) {
if (PUA1_START <= wc && wc < PUA1_END) return 1;
if (PUA2_START <= wc && wc < PUA2_END) return 1;
if (PUA3_START <= wc && wc < PUA3_END) return 1;
return 0;
}
/// We need this because there are too many implementations that don't return the proper answer for
/// some code points. See issue #3050.
int fish_iswalnum(wint_t wc) {
if (fish_reserved_codepoint(wc)) return 0;
if (fish_is_pua(wc)) return 0;
return iswalnum(wc);
}
#if 0
/// We need this because there are too many implementations that don't return the proper answer for
/// some code points. See issue #3050.
int fish_iswalpha(wint_t wc) {
if (fish_reserved_codepoint(wc)) return 0;
if (fish_is_pua(wc)) return 0;
return iswalpha(wc);
}
#endif
/// We need this because there are too many implementations that don't return the proper answer for
/// some code points. See issue #3050.
int fish_iswgraph(wint_t wc) {
if (fish_reserved_codepoint(wc)) return 0;
if (fish_is_pua(wc)) return 1;
return iswgraph(wc);
}
/// Convenience variants on fish_wcwswidth().
///
/// See fallback.h for the normal definitions.
int fish_wcswidth(const wchar_t *str) { return fish_wcswidth(str, std::wcslen(str)); }
/// Convenience variants on fish_wcwswidth().
///
/// See fallback.h for the normal definitions.
int fish_wcswidth(const wcstring &str) { return fish_wcswidth(str.c_str(), str.size()); }
locale_t fish_c_locale() {
static const locale_t loc = newlocale(LC_ALL_MASK, "C", nullptr);
return loc;
}
/// Like fish_wcstol(), but fails on a value outside the range of an int.
///
/// This is needed because BSD and GNU implementations differ in several ways that make it really
/// annoying to use them in a portable fashion.
///
/// The caller doesn't have to zero errno. Sets errno to -1 if the int ends with something other
/// than a digit. Leading whitespace is ignored (per the base wcstol implementation). Trailing
/// whitespace is also ignored. We also treat empty strings and strings containing only whitespace
/// as invalid.
int fish_wcstoi(const wchar_t *str, const wchar_t **endptr, int base) {
while (iswspace(*str)) ++str; // skip leading whitespace
if (!*str) { // this is because some implementations don't handle this sensibly
errno = EINVAL;
if (endptr) *endptr = str;
return 0;
}
errno = 0;
wchar_t *_endptr;
long result = std::wcstol(str, &_endptr, base);
if (result > INT_MAX) {
result = INT_MAX;
errno = ERANGE;
} else if (result < INT_MIN) {
result = INT_MIN;
errno = ERANGE;
}
while (iswspace(*_endptr)) ++_endptr; // skip trailing whitespace
if (!errno && *_endptr) {
if (_endptr == str) {
errno = EINVAL;
} else {
errno = -1;
}
}
if (endptr) *endptr = _endptr;
return static_cast<int>(result);
}
/// An enhanced version of wcstol().
///
/// This is needed because BSD and GNU implementations differ in several ways that make it really
/// annoying to use them in a portable fashion.
///
/// The caller doesn't have to zero errno. Sets errno to -1 if the int ends with something other
/// than a digit. Leading whitespace is ignored (per the base wcstol implementation). Trailing
/// whitespace is also ignored.
long fish_wcstol(const wchar_t *str, const wchar_t **endptr, int base) {
while (iswspace(*str)) ++str; // skip leading whitespace
if (!*str) { // this is because some implementations don't handle this sensibly
errno = EINVAL;
if (endptr) *endptr = str;
return 0;
}
errno = 0;
wchar_t *_endptr;
long result = std::wcstol(str, &_endptr, base);
while (iswspace(*_endptr)) ++_endptr; // skip trailing whitespace
if (!errno && *_endptr) {
if (_endptr == str) {
errno = EINVAL;
} else {
errno = -1;
}
}
if (endptr) *endptr = _endptr;
return result;
}
/// An enhanced version of wcstoll().
///
/// This is needed because BSD and GNU implementations differ in several ways that make it really
/// annoying to use them in a portable fashion.
///
/// The caller doesn't have to zero errno. Sets errno to -1 if the int ends with something other
/// than a digit. Leading whitespace is ignored (per the base wcstoll implementation). Trailing
/// whitespace is also ignored.
long long fish_wcstoll(const wchar_t *str, const wchar_t **endptr, int base) {
while (iswspace(*str)) ++str; // skip leading whitespace
if (!*str) { // this is because some implementations don't handle this sensibly
errno = EINVAL;
if (endptr) *endptr = str;
return 0;
}
errno = 0;
wchar_t *_endptr;
long long result = std::wcstoll(str, &_endptr, base);
while (iswspace(*_endptr)) ++_endptr; // skip trailing whitespace
if (!errno && *_endptr) {
if (_endptr == str) {
errno = EINVAL;
} else {
errno = -1;
}
}
if (endptr) *endptr = _endptr;
return result;
}
/// An enhanced version of wcstoull().
///
/// This is needed because BSD and GNU implementations differ in several ways that make it really
/// annoying to use them in a portable fashion.
///
/// The caller doesn't have to zero errno. Sets errno to -1 if the int ends with something other
/// than a digit. Leading minus is considered invalid. Leading whitespace is ignored (per the base
/// wcstoull implementation). Trailing whitespace is also ignored.
unsigned long long fish_wcstoull(const wchar_t *str, const wchar_t **endptr, int base) {
while (iswspace(*str)) ++str; // skip leading whitespace
if (!*str || // this is because some implementations don't handle this sensibly
*str == '-') // disallow minus as the first character to avoid questionable wrap-around
{
errno = EINVAL;
if (endptr) *endptr = str;
return 0;
}
errno = 0;
wchar_t *_endptr;
unsigned long long result = std::wcstoull(str, &_endptr, base);
while (iswspace(*_endptr)) ++_endptr; // skip trailing whitespace
if (!errno && *_endptr) {
if (_endptr == str) {
errno = EINVAL;
} else {
errno = -1;
}
}
if (endptr) *endptr = _endptr;
return result;
}
/// Like wcstod(), but wcstod() is enormously expensive on some platforms so this tries to have a
/// fast path.
double fish_wcstod(const wchar_t *str, wchar_t **endptr) {
// The "fast path." If we're all ASCII and we fit inline, use strtod().
char narrow[128];
size_t len = std::wcslen(str);
size_t len_plus_0 = 1 + len;
auto is_digit = [](wchar_t c) { return '0' <= c && c <= '9'; };
if (len_plus_0 <= sizeof narrow && std::all_of(str, str + len, is_digit)) {
// Fast path. Copy the string into a local buffer and run strtod() on it.
// We can ignore the locale-taking version because we are limited to ASCII digits.
std::copy(str, str + len_plus_0, narrow);
char *narrow_endptr = nullptr;
double ret = strtod(narrow, endptr ? &narrow_endptr : nullptr);
if (endptr) {
assert(narrow_endptr && "narrow_endptr should not be null");
*endptr = const_cast<wchar_t *>(str + (narrow_endptr - narrow));
}
return ret;
}
return wcstod_l(str, endptr, fish_c_locale());
}
file_id_t file_id_t::from_stat(const struct stat &buf) {
file_id_t result = {};
result.device = buf.st_dev;
result.inode = buf.st_ino;
result.size = buf.st_size;
result.change_seconds = buf.st_ctime;
result.mod_seconds = buf.st_mtime;
#ifdef HAVE_STRUCT_STAT_ST_CTIME_NSEC
result.change_nanoseconds = buf.st_ctime_nsec;
result.mod_nanoseconds = buf.st_mtime_nsec;
#elif defined(__APPLE__)
result.change_nanoseconds = buf.st_ctimespec.tv_nsec;
result.mod_nanoseconds = buf.st_mtimespec.tv_nsec;
#elif defined(_BSD_SOURCE) || defined(_SVID_SOURCE) || defined(_XOPEN_SOURCE)
result.change_nanoseconds = buf.st_ctim.tv_nsec;
result.mod_nanoseconds = buf.st_mtim.tv_nsec;
#else
result.change_nanoseconds = 0;
result.mod_nanoseconds = 0;
#endif
return result;
}
file_id_t file_id_for_fd(int fd) {
file_id_t result = kInvalidFileID;
struct stat buf = {};
if (fd >= 0 && 0 == fstat(fd, &buf)) {
result = file_id_t::from_stat(buf);
}
return result;
}
file_id_t file_id_for_path(const wcstring &path) {
file_id_t result = kInvalidFileID;
struct stat buf = {};
if (0 == wstat(path, &buf)) {
result = file_id_t::from_stat(buf);
}
return result;
}
file_id_t file_id_for_path(const std::string &path) {
file_id_t result = kInvalidFileID;
struct stat buf = {};
if (0 == stat(path.c_str(), &buf)) {
result = file_id_t::from_stat(buf);
}
return result;
}
bool file_id_t::operator==(const file_id_t &rhs) const { return this->compare_file_id(rhs) == 0; }
bool file_id_t::operator!=(const file_id_t &rhs) const { return !(*this == rhs); }
template <typename T>
int compare(T a, T b) {
if (a < b) {
return -1;
} else if (a > b) {
return 1;
}
return 0;
}
int file_id_t::compare_file_id(const file_id_t &rhs) const {
// Compare each field, stopping when we get to a non-equal field.
int ret = 0;
if (!ret) ret = compare(device, rhs.device);
if (!ret) ret = compare(inode, rhs.inode);
if (!ret) ret = compare(size, rhs.size);
if (!ret) ret = compare(change_seconds, rhs.change_seconds);
if (!ret) ret = compare(change_nanoseconds, rhs.change_nanoseconds);
if (!ret) ret = compare(mod_seconds, rhs.mod_seconds);
if (!ret) ret = compare(mod_nanoseconds, rhs.mod_nanoseconds);
return ret;
}
bool file_id_t::operator<(const file_id_t &rhs) const { return this->compare_file_id(rhs) < 0; }