/* vi: set sw=4 ts=4: */ /* * nice implementation for busybox * * 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 * */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include <limits.h> #include <errno.h> #include <unistd.h> #include <sys/time.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... */ bb_default_error_retval = (errno == ENOENT) ? 127 : 126; /* SUSv3 */ bb_perror_msg_and_die("%s", *argv); }