sbase/env.c
FRIGN 6f207dac5f Don't return but _exit after failed exec*() and fork()
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
2015-03-09 01:12:59 +01:00

50 lines
790 B
C

/* See LICENSE file for copyright and license details. */
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "util.h"
extern char **environ;
static void
usage(void)
{
eprintf("usage: %s [-i] [-u var] ... [var=value] ... [cmd [arg ...]]\n", argv0);
}
int
main(int argc, char *argv[])
{
int savederrno;
ARGBEGIN {
case 'i':
if (environ)
*environ = NULL;
break;
case 'u':
unsetenv(EARGF(usage()));
break;
default:
usage();
} ARGEND;
for (; *argv && strchr(*argv, '='); argc--, argv++)
putenv(*argv);
if (*argv) {
execvp(*argv, argv);
savederrno = errno;
weprintf("execvp %s:", *argv);
_exit(126 + (savederrno == EEXIST));
}
for (; environ && *environ; environ++)
puts(*environ);
return 0;
}