sbase/nice.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

49 lines
798 B
C

/* See LICENSE file for copyright and license details. */
#include <sys/resource.h>
#include <errno.h>
#include <stdlib.h>
#include <unistd.h>
#include "util.h"
static void
usage(void)
{
eprintf("usage: %s [-n inc] cmd [arg ...]\n", argv0);
}
int
main(int argc, char *argv[])
{
int val = 10, r, savederrno;
ARGBEGIN {
case 'n':
val = estrtonum(EARGF(usage()), PRIO_MIN, PRIO_MAX);
break;
default:
usage();
break;
} ARGEND;
if (!argc)
usage();
errno = 0;
r = getpriority(PRIO_PROCESS, 0);
if (errno)
weprintf("getpriority:");
else
val += r;
LIMIT(val, PRIO_MIN, PRIO_MAX);
if (setpriority(PRIO_PROCESS, 0, val) < 0)
weprintf("setpriority:");
execvp(argv[0], argv);
savederrno = errno;
weprintf("execvp %s:", argv[0]);
_exit(126 + (savederrno == ENOENT));
}