diff options
author | Manuel Novoa III <mjn3@codepoet.org> | 2005-02-13 23:14:05 +0300 |
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committer | Manuel Novoa III <mjn3@codepoet.org> | 2005-02-13 23:14:05 +0300 |
commit | 2c511609c4d92ee4e3e603d449c13579d1ea641a (patch) | |
tree | d57c8dd9efa4c30cd01290f878cae688ae792cc0 /coreutils/nice.c | |
parent | d2fe81706c9d65dd1580c85338036cc403364fae (diff) |
Add 'nice' and replace 'renice' with a new implementation.
Diffstat (limited to 'coreutils/nice.c')
-rw-r--r-- | coreutils/nice.c | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/coreutils/nice.c b/coreutils/nice.c new file mode 100644 index 000000000..b66f9d82d --- /dev/null +++ b/coreutils/nice.c @@ -0,0 +1,86 @@ +/* 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); +} |