sbase/renice.c

94 lines
1.5 KiB
C

/* See LICENSE file for copyright and license details. */
#include <sys/resource.h>
#include <errno.h>
#include <pwd.h>
#include <stdlib.h>
#include "util.h"
#ifndef PRIO_MIN
#define PRIO_MIN -NZERO
#endif
#ifndef PRIO_MAX
#define PRIO_MAX (NZERO-1)
#endif
static int
renice(int which, int who, long adj)
{
errno = 0;
adj += getpriority(which, who);
if (errno) {
weprintf("getpriority %d:", who);
return 0;
}
adj = MAX(PRIO_MIN, MIN(adj, PRIO_MAX));
if (setpriority(which, who, (int)adj) < 0) {
weprintf("setpriority %d:", who);
return 0;
}
return 1;
}
static void
usage(void)
{
eprintf("usage: %s -n num [-g | -p | -u] id ...\n", argv0);
}
int
main(int argc, char *argv[])
{
const char *adj = NULL;
long val;
int which = PRIO_PROCESS, ret = 0;
struct passwd *pw;
int who;
ARGBEGIN {
case 'n':
adj = EARGF(usage());
break;
case 'g':
which = PRIO_PGRP;
break;
case 'p':
which = PRIO_PROCESS;
break;
case 'u':
which = PRIO_USER;
break;
default:
usage();
} ARGEND
if (!argc || !adj)
usage();
val = estrtonum(adj, PRIO_MIN, PRIO_MAX);
for (; *argv; argc--, argv++) {
if (which == PRIO_USER) {
errno = 0;
if (!(pw = getpwnam(*argv))) {
if (errno)
weprintf("getpwnam %s:", *argv);
else
weprintf("getpwnam %s: no user found\n", *argv);
ret = 1;
continue;
}
who = pw->pw_uid;
} else {
who = estrtonum(*argv, 1, INT_MAX);
}
if (!renice(which, who, val))
ret = 1;
}
return ret;
}