sbase/nice.c
sin 166bc3052e Use PRIO_{MIN,MAX} instead of NZERO
Some systems do not define NZERO.  NZERO seems to be an XSI extension
and PRIO_{MIN,MAX} is not specified by POSIX but most relevant systems
define it.
2014-11-17 15:02:51 +00:00

50 lines
920 B
C

/* See LICENSE file for copyright and license details. */
#include <errno.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/resource.h>
#include <sys/time.h>
#include <unistd.h>
#include "util.h"
static void
usage(void)
{
eprintf("usage: nice [-n inc] command [options ...]\n");
}
int
main(int argc, char *argv[])
{
long val = 10;
int savederrno;
ARGBEGIN {
case 'n':
val = estrtol(EARGF(usage()), 10);
break;
default:
usage();
break;
} ARGEND;
if (argc == 0)
usage();
errno = 0;
val += getpriority(PRIO_PROCESS, 0);
if (errno != 0)
weprintf("getpriority:");
val = MAX(PRIO_MIN, MIN(val, PRIO_MAX));
if (setpriority(PRIO_PROCESS, 0, val) != 0)
weprintf("setpriority:");
/* POSIX specifies the nice failure still invokes the command */
execvp(argv[0], argv);
savederrno = errno;
weprintf("execvp %s:", argv[0]);
return (savederrno == ENOENT)? 127 : 126;
}