cosmopolitan/libc/proc/system.c
Jōshin e16a7d8f3b
flip et / noet in modelines
`et` means `expandtab`.

```sh
rg 'vi: .* :vi' -l -0 | \
  xargs -0 sed -i '' 's/vi: \(.*\) et\(.*\)  :vi/vi: \1 xoet\2:vi/'
rg 'vi: .*  :vi' -l -0 | \
  xargs -0 sed -i '' 's/vi: \(.*\)noet\(.*\):vi/vi: \1et\2  :vi/'
rg 'vi: .*  :vi' -l -0 | \
  xargs -0 sed -i '' 's/vi: \(.*\)xoet\(.*\):vi/vi: \1noet\2:vi/'
```
2023-12-07 22:17:11 -05:00

98 lines
4.7 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi │
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/calls/blockcancel.internal.h"
#include "libc/calls/calls.h"
#include "libc/calls/struct/rusage.h"
#include "libc/calls/struct/sigaction.h"
#include "libc/dce.h"
#include "libc/errno.h"
#include "libc/intrin/weaken.h"
#include "libc/log/log.h"
#include "libc/paths.h"
#include "libc/runtime/runtime.h"
#include "libc/str/str.h"
#include "libc/sysv/consts/ok.h"
#include "libc/sysv/consts/sig.h"
#include "libc/thread/thread.h"
/**
* Launches program with system command interpreter.
*
* This implementation embeds the Cosmopolitan Command Interpreter which
* provides Bourne-like syntax on all platforms, including Windows. Many
* builtin commands are included, e.g. exit, cd, rm, [, cat, wait, exec,
* env, echo, read, true, test, kill, touch, rmdir, mkdir, false, mktemp
* and usleep. It's also possible to __static_yoink() the symbols `_tr`,
* `_sed`, `_awk`, and `_curl` for the tr, sed, awk and curl commands if
* you're using the Cosmopolitan mono-repo.
*
* If you just have a program name and arguments, and you don't need the
* full power of a UNIX-like shell, then consider using the Cosmopolitan
* provided API systemvpe() instead. It provides a safer alternative for
* variable arguments than shell script escaping. It lets you clean your
* environment variables, for even more safety. Finally it's 10x faster.
*
* It's important to check the returned status code. For example, if you
* press CTRL-C while running your program you'll expect it to terminate
* however that won't be the case if the SIGINT gets raised while inside
* the system() function. If the child process doesn't handle the signal
* then this will return e.g. WIFSIGNALED(ws) && WTERMSIG(ws) == SIGINT.
*
* @param cmdline is a unix shell script
* @return -1 if child process couldn't be created, otherwise a wait
* status that can be accessed using macros like WEXITSTATUS(s),
* WIFSIGNALED(s), WTERMSIG(s), etc.
* @see systemve()
* @threadsafe
*/
int system(const char *cmdline) {
int pid, wstatus;
sigset_t chldmask, savemask;
if (!cmdline) return 1;
sigemptyset(&chldmask);
sigaddset(&chldmask, SIGINT);
sigaddset(&chldmask, SIGQUIT);
sigaddset(&chldmask, SIGCHLD);
sigprocmask(SIG_BLOCK, &chldmask, &savemask);
if (!(pid = fork())) {
sigprocmask(SIG_SETMASK, &savemask, 0);
_Exit(_cocmd(3, (char *[]){"system", "-c", (char *)cmdline, 0}, environ));
} else if (pid == -1) {
wstatus = -1;
} else {
struct sigaction ignore, saveint, savequit;
ignore.sa_flags = 0;
ignore.sa_handler = SIG_IGN;
sigemptyset(&ignore.sa_mask);
sigaction(SIGINT, &ignore, &saveint);
sigaction(SIGQUIT, &ignore, &savequit);
BLOCK_CANCELATION;
while (wait4(pid, &wstatus, 0, 0) == -1) {
if (errno != EINTR) {
wstatus = -1;
break;
}
}
ALLOW_CANCELATION;
sigaction(SIGQUIT, &savequit, 0);
sigaction(SIGINT, &saveint, 0);
}
sigprocmask(SIG_SETMASK, &savemask, 0);
return wstatus;
}