+/* vi: set sw=4 ts=4: */
/*
- * Mini renice implementation for busybox
+ * renice implementation for busybox
*
+ * Copyright (C) 2005 Manuel Novoa III <mjn3@codepoet.org>
*
- * Copyright (C) 2000 Dave 'Kill a Cop' Cinege <dcinege@psychosis.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
+ */
+
+/* Notes:
+ * Setting an absolute priority was obsoleted in SUSv2 and removed
+ * in SUSv3. However, the common linux version of renice does
+ * absolute and not relative. So we'll continue supporting absolute,
+ * although the stdout logging has been removed since both SUSv2 and
+ * SUSv3 specify that stdout isn't used.
*
+ * This version is lenient in that it doesn't require any IDs. The
+ * options -p, -g, and -u are treated as mode switches for the
+ * following IDs (if any). Multiple switches are allowed.
*/
+//config:config RENICE
+//config: bool "renice"
+//config: default y
+//config: help
+//config: Renice alters the scheduling priority of one or more running
+//config: processes.
+
+//applet:IF_RENICE(APPLET(renice, BB_DIR_USR_BIN, BB_SUID_DROP))
+
+//kbuild:lib-$(CONFIG_RENICE) += renice.o
-#include <stdio.h>
-#include <errno.h>
-#include <stdlib.h>
-#include <sys/time.h>
+//usage:#define renice_trivial_usage
+//usage: "[-n] PRIORITY [[-p | -g | -u] ID...]..."
+//usage:#define renice_full_usage "\n\n"
+//usage: "Change scheduling priority of a running process\n"
+//usage: "\n -n Add PRIORITY to current nice value"
+//usage: "\n Without -n, nice value is set to PRIORITY"
+//usage: "\n -p Process ids (default)"
+//usage: "\n -g Process group ids"
+//usage: "\n -u Process user names"
+
+#include "libbb.h"
#include <sys/resource.h>
-#include "busybox.h"
+void BUG_bad_PRIO_PROCESS(void);
+void BUG_bad_PRIO_PGRP(void);
+void BUG_bad_PRIO_USER(void);
-extern int renice_main(int argc, char **argv)
+int renice_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int renice_main(int argc UNUSED_PARAM, char **argv)
{
- int prio, status = EXIT_SUCCESS;
-
- if (argc < 3) bb_show_usage();
-
- prio = atoi(*++argv);
- if (prio > 20) prio = 20;
- if (prio < -20) prio = -20;
-
- while (*++argv) {
- int ps = atoi(*argv);
- int oldp = getpriority(PRIO_PROCESS, ps);
-
- if (setpriority(PRIO_PROCESS, ps, prio) == 0) {
- printf("%d: old priority %d, new priority %d\n", ps, oldp, prio );
+ static const char Xetpriority_msg[] ALIGN1 = "%cetpriority";
+
+ int retval = EXIT_SUCCESS;
+ int which = PRIO_PROCESS; /* Default 'which' value. */
+ int use_relative = 0;
+ int adjustment, new_priority;
+ unsigned who;
+ char *arg;
+
+ /* Yes, they are not #defines in glibc 2.4! #if won't work */
+ if (PRIO_PROCESS < CHAR_MIN || PRIO_PROCESS > CHAR_MAX)
+ BUG_bad_PRIO_PROCESS();
+ if (PRIO_PGRP < CHAR_MIN || PRIO_PGRP > CHAR_MAX)
+ BUG_bad_PRIO_PGRP();
+ if (PRIO_USER < CHAR_MIN || PRIO_USER > CHAR_MAX)
+ BUG_bad_PRIO_USER();
+
+ arg = *++argv;
+
+ /* Check if we are using a relative adjustment. */
+ if (arg && arg[0] == '-' && arg[1] == 'n') {
+ use_relative = 1;
+ if (!arg[2])
+ arg = *++argv;
+ else
+ arg += 2;
+ }
+
+ if (!arg) { /* No args? Then show usage. */
+ bb_show_usage();
+ }
+
+ /* Get the priority adjustment (absolute or relative). */
+ adjustment = xatoi_range(arg, INT_MIN/2, INT_MAX/2);
+
+ while ((arg = *++argv) != NULL) {
+ /* Check for a mode switch. */
+ if (arg[0] == '-' && arg[1]) {
+ static const char opts[] ALIGN1 = {
+ 'p', 'g', 'u', 0, PRIO_PROCESS, PRIO_PGRP, PRIO_USER
+ };
+ const char *p = strchr(opts, arg[1]);
+ if (p) {
+ which = p[4];
+ if (!arg[2])
+ continue;
+ arg += 2;
+ }
+ }
+
+ /* Process an ID arg. */
+ if (which == PRIO_USER) {
+ struct passwd *p;
+ p = getpwnam(arg);
+ if (!p) {
+ bb_error_msg("unknown user %s", arg);
+ goto HAD_ERROR;
+ }
+ who = p->pw_uid;
+ } else {
+ who = bb_strtou(arg, NULL, 10);
+ if (errno) {
+ bb_error_msg("invalid number '%s'", arg);
+ goto HAD_ERROR;
+ }
+ }
+
+ /* Get priority to use, and set it. */
+ if (use_relative) {
+ int old_priority;
+
+ errno = 0; /* Needed for getpriority error detection. */
+ old_priority = getpriority(which, who);
+ if (errno) {
+ bb_perror_msg(Xetpriority_msg, 'g');
+ goto HAD_ERROR;
+ }
+
+ new_priority = old_priority + adjustment;
} else {
- bb_perror_msg("%d: setpriority", ps);
- status = EXIT_FAILURE;
+ new_priority = adjustment;
}
+
+ if (setpriority(which, who, new_priority) == 0) {
+ continue;
+ }
+
+ bb_perror_msg(Xetpriority_msg, 's');
+ HAD_ERROR:
+ retval = EXIT_FAILURE;
}
- return status;
+ /* No need to check for errors outputing to stderr since, if it
+ * was used, the HAD_ERROR label was reached and retval was set. */
+
+ return retval;
}
projects / oweals / busybox.git / blobdiff