6f207dac5f
Quoting POSIX[0]: "Care should be taken, also, to call _exit() rather than exit() if exec cannot be used, since exit() flushes and closes standard I/O channels, thereby damaging the parent process' standard I/O data structures. (Even with fork(), it is wrong to call exit(), since buffered data would then be flushed twice.)" [0]: http://pubs.opengroup.org/onlinepubs/009695399/functions/vfork.html
45 lines
622 B
C
45 lines
622 B
C
/* See LICENSE file for copyright and license details. */
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#include <errno.h>
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#include <unistd.h>
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#include "util.h"
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static void
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usage(void)
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{
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eprintf("usage: %s cmd [arg ...]\n", argv0);
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}
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int
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main(int argc, char *argv[])
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{
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int savederrno;
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ARGBEGIN {
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default:
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usage();
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} ARGEND;
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if (!argc)
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usage();
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if (getpgrp() == getpid()) {
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switch (fork()) {
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case -1:
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weprintf("fork:");
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_exit(1);
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case 0:
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break;
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default:
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return 0;
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}
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}
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if (setsid() < 0)
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eprintf("setsid:");
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execvp(argv[0], argv);
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savederrno = errno;
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weprintf("execvp %s:", argv[0]);
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_exit(126 + (savederrno == ENOENT));
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}
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