73 lines
1.7 KiB
C
73 lines
1.7 KiB
C
/* vi: set sw=4 ts=4: */
|
|
/*
|
|
* nice implementation for busybox
|
|
*
|
|
* Copyright (C) 2005 Manuel Novoa III <mjn3@codepoet.org>
|
|
*
|
|
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
|
|
*/
|
|
|
|
#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"
|
|
|
|
static inline int int_add_no_wrap(int a, int b)
|
|
{
|
|
int s = a + b;
|
|
|
|
if (b < 0) {
|
|
if (s > a) s = INT_MIN;
|
|
} else {
|
|
if (s < a) s = INT_MAX;
|
|
}
|
|
|
|
return s;
|
|
}
|
|
|
|
int nice_main(int argc, 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);
|
|
}
|
|
|
|
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! */
|
|
bb_show_usage();
|
|
}
|
|
adjustment = bb_xgetlarg(argv[1], 10, INT_MIN, INT_MAX);
|
|
argv += 2;
|
|
}
|
|
|
|
{ /* Set our priority. Handle integer wrapping for old + adjust. */
|
|
int new_priority = int_add_no_wrap(old_priority, adjustment);
|
|
|
|
if (setpriority(PRIO_PROCESS, 0, new_priority) < 0) {
|
|
bb_perror_msg_and_die(Xetpriority_msg, 's');
|
|
}
|
|
}
|
|
|
|
execvp(*argv, argv); /* Now exec the desired program. */
|
|
|
|
/* The exec failed... */
|
|
xfunc_error_retval = (errno == ENOENT) ? 127 : 126; /* SUSv3 */
|
|
bb_perror_msg_and_die("%s", *argv);
|
|
}
|