1 /* nice -- run a program with modified niceness
2 Copyright (C) 1990-2013 Free Software Foundation, Inc.
4 This program is free software: you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation, either version 3 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program. If not, see <http://www.gnu.org/licenses/>. */
17 /* David MacKenzie <djm@gnu.ai.mit.edu> */
22 #include <sys/types.h>
27 /* Include this after "system.h" so we're sure to have definitions
28 (from time.h or sys/time.h) required for e.g. the ru_utime member. */
29 # include <sys/resource.h>
36 /* The official name of this program (e.g., no 'g' prefix). */
37 #define PROGRAM_NAME "nice"
39 #define AUTHORS proper_name ("David MacKenzie")
42 # define GET_NICENESS() nice (0)
44 # define GET_NICENESS() getpriority (PRIO_PROCESS, 0)
51 /* This is required for Darwin Kernel Version 7.7.0. */
57 static struct option const longopts[] =
59 {"adjustment", required_argument, NULL, 'n'},
60 {GETOPT_HELP_OPTION_DECL},
61 {GETOPT_VERSION_OPTION_DECL},
68 if (status != EXIT_SUCCESS)
72 printf (_("Usage: %s [OPTION] [COMMAND [ARG]...]\n"), program_name);
74 Run COMMAND with an adjusted niceness, which affects process scheduling.\n\
75 With no COMMAND, print the current niceness. Niceness values range from\n\
76 %d (most favorable to the process) to %d (least favorable to the process).\n\
80 emit_mandatory_arg_note ();
83 -n, --adjustment=N add integer N to the niceness (default 10)\n\
85 fputs (HELP_OPTION_DESCRIPTION, stdout);
86 fputs (VERSION_OPTION_DESCRIPTION, stdout);
87 printf (USAGE_BUILTIN_WARNING, PROGRAM_NAME);
88 emit_ancillary_info ();
94 perm_related_errno (int err)
96 return err == EACCES || err == EPERM;
100 main (int argc, char **argv)
102 int current_niceness;
104 char const *adjustment_given = NULL;
108 initialize_main (&argc, &argv);
109 set_program_name (argv[0]);
110 setlocale (LC_ALL, "");
111 bindtextdomain (PACKAGE, LOCALEDIR);
112 textdomain (PACKAGE);
114 initialize_exit_failure (EXIT_CANCELED);
115 atexit (close_stdout);
117 for (i = 1; i < argc; /* empty */)
119 char const *s = argv[i];
121 if (s[0] == '-' && ISDIGIT (s[1 + (s[1] == '-' || s[1] == '+')]))
123 adjustment_given = s + 1;
129 int fake_argc = argc - (i - 1);
130 char **fake_argv = argv + (i - 1);
132 /* Ensure that any getopt diagnostics use the right name. */
133 fake_argv[0] = argv[0];
135 /* Initialize getopt_long's internal state. */
138 c = getopt_long (fake_argc, fake_argv, "+n:", longopts, NULL);
144 adjustment_given = optarg;
150 case_GETOPT_HELP_CHAR;
152 case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
155 usage (EXIT_CANCELED);
164 if (adjustment_given)
166 /* If the requested adjustment is outside the valid range,
167 silently bring it to just within range; this mimics what
168 "setpriority" and "nice" do. */
169 enum { MIN_ADJUSTMENT = 1 - 2 * NZERO, MAX_ADJUSTMENT = 2 * NZERO - 1 };
171 if (LONGINT_OVERFLOW < xstrtol (adjustment_given, NULL, 10, &tmp, ""))
172 error (EXIT_CANCELED, 0, _("invalid adjustment %s"),
173 quote (adjustment_given));
174 adjustment = MAX (MIN_ADJUSTMENT, MIN (tmp, MAX_ADJUSTMENT));
179 if (adjustment_given)
181 error (0, 0, _("a command must be given with an adjustment"));
182 usage (EXIT_CANCELED);
184 /* No command given; print the niceness. */
186 current_niceness = GET_NICENESS ();
187 if (current_niceness == -1 && errno != 0)
188 error (EXIT_CANCELED, errno, _("cannot get niceness"));
189 printf ("%d\n", current_niceness);
195 ok = (nice (adjustment) != -1 || errno == 0);
197 current_niceness = GET_NICENESS ();
198 if (current_niceness == -1 && errno != 0)
199 error (EXIT_CANCELED, errno, _("cannot get niceness"));
200 ok = (setpriority (PRIO_PROCESS, 0, current_niceness + adjustment) == 0);
204 error (perm_related_errno (errno) ? 0
205 : EXIT_CANCELED, errno, _("cannot set niceness"));
206 /* error() flushes stderr, but does not check for write failure.
207 Normally, we would catch this via our atexit() hook of
208 close_stdout, but execvp() gets in the way. If stderr
209 encountered a write failure, there is no need to try calling
212 exit (EXIT_CANCELED);
215 execvp (argv[i], &argv[i]);
218 int exit_status = (errno == ENOENT ? EXIT_ENOENT : EXIT_CANNOT_INVOKE);
219 error (0, errno, "%s", argv[i]);