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71 lines
2.0 KiB
C
71 lines
2.0 KiB
C
/** \file exec.h
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Prototypes for functions for executing a program
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*/
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#ifndef FISH_EXEC_H
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/**
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Header guard
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*/
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#define FISH_EXEC_H
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#include <wchar.h>
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#include "proc.h"
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#include "util.h"
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/**
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pipe redirection error message
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*/
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#define PIPE_ERROR _(L"An error occurred while setting up pipe")
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/**
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Execute the processes specified by j.
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I've put a fair bit of work into making builtins behave like other
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programs as far as pipes are concerned. Unlike i.e. bash, builtins
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can pipe to other builtins with arbitrary amounts of data, and so
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on. To do this, after a builtin is run in the real process, it
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forks and a dummy process is created, responsible for writing the
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output of the builtin. This is surprisingly cheap on my computer,
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probably because of the marvels of copy on write forking.
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This rule is short circuted in the case where a builtin does not
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output to a pipe and does in fact not output anything. The speed
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improvement from this optimization is not noticable on a normal
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computer/OS in regular use, but the promiscous amounts of forking
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that resulted was responsible for a huge slowdown when using
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Valgrind as well as when doing complex command-specific
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completions.
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*/
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void exec( job_t *j );
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/**
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Evaluate the expression cmd in a subshell, add the outputs into the
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list l. On return, the status flag as returned bu \c
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proc_gfet_last_status will not be changed.
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\param cmd the command to execute
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\param l The list to insert output into.If \c l is zero, the output will be discarded.
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\return the status of the last job to exit, or -1 if en error was encountered.
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*/
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__warn_unused int exec_subshell( const wchar_t *cmd,
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array_list_t *l );
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/**
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Loops over close until thesyscall was run without beeing
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interrupted. Thenremoves the fd from the open_fds list.
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*/
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void exec_close( int fd );
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/**
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Call pipe(), and add resulting fds to open_fds, the list of opend
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file descriptors for pipes.
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*/
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int exec_pipe( int fd[2]);
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#endif
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