*
* Copyright (C) 2005 Manuel Novoa III <mjn3@codepoet.org>
*
- * 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.
*/
+//config:config NICE
+//config: bool "nice (1.8 kb)"
+//config: default y
+//config: help
+//config: nice runs a program with modified scheduling priority.
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <limits.h>
-#include <errno.h>
-#include <unistd.h>
-#include <sys/resource.h>
-#include "busybox.h"
+//applet:IF_NICE(APPLET_NOEXEC(nice, nice, BB_DIR_BIN, BB_SUID_DROP, nice))
-static inline int int_add_no_wrap(int a, int b)
-{
- int s = a + b;
+//kbuild:lib-$(CONFIG_NICE) += nice.o
- if (b < 0) {
- if (s > a) s = INT_MIN;
- } else {
- if (s < a) s = INT_MAX;
- }
+//usage:#define nice_trivial_usage
+//usage: "[-n ADJUST] [PROG ARGS]"
+//usage:#define nice_full_usage "\n\n"
+//usage: "Change scheduling priority, run PROG\n"
+//usage: "\n -n ADJUST Adjust priority by ADJUST"
- return s;
-}
+#include "libbb.h"
-int nice_main(int argc, char **argv)
+int nice_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int nice_main(int argc UNUSED_PARAM, char **argv)
{
- static const char Xetpriority_msg[] = "cannot %cet priority";
-
int old_priority, adjustment;
- errno = 0; /* Needed for getpriority error detection. */
old_priority = getpriority(PRIO_PROCESS, 0);
- if (errno) {
- bb_perror_msg_and_die(Xetpriority_msg, 'g');
- }
- if (!*++argv) { /* No args, so (GNU) output current nice value. */
- bb_printf("%d\n", old_priority);
- bb_fflush_stdout_and_exit(EXIT_SUCCESS);
+ if (!*++argv) { /* No args, so (GNU) output current nice value. */
+ printf("%d\n", old_priority);
+ fflush_stdout_and_exit(EXIT_SUCCESS);
}
- adjustment = 10; /* Set default adjustment. */
+ adjustment = 10; /* Set default adjustment. */
- if ((argv[0][0] == '-') && (argv[0][1] == 'n') && !argv[0][2]) { /* "-n" */
- if (argc < 4) { /* Missing priority and/or utility! */
+ if (argv[0][0] == '-') {
+ char *nnn = argv[0] + 1;
+ if (nnn[0] == 'n') { /* -n */
+ nnn += 1;
+ if (!nnn[0]) { /* "-n NNN" */
+ nnn = *++argv;
+ }
+ /* else: "-nNNN" (w/o space) */
+ }
+ /* else: "-NNN" (NNN may be negative) - same as "-n NNN" */
+
+ if (!nnn || !argv[1]) { /* Missing priority or PROG! */
bb_show_usage();
}
- adjustment = bb_xgetlarg(argv[1], 10, INT_MIN, INT_MAX);
- argv += 2;
+ adjustment = xatoi_range(nnn, INT_MIN/2, INT_MAX/2);
+ argv++;
}
- { /* Set our priority. Handle integer wrapping for old + adjust. */
- int new_priority = int_add_no_wrap(old_priority, adjustment);
+ { /* Set our priority. */
+ int prio = old_priority + adjustment;
- if (setpriority(PRIO_PROCESS, 0, new_priority) < 0) {
- bb_perror_msg_and_die(Xetpriority_msg, 's');
+ if (setpriority(PRIO_PROCESS, 0, prio) < 0) {
+ bb_perror_msg_and_die("setpriority(%d)", prio);
}
}
- execvp(*argv, argv); /* Now exec the desired program. */
-
- /* The exec failed... */
- bb_default_error_retval = (errno == ENOENT) ? 127 : 126; /* SUSv3 */
- bb_perror_msg_and_die("%s", *argv);
+ BB_EXECVP_or_die(argv);
}