/* nice -- run a program with modified niceness This is the nice utility
Copyright (C) 1990-2018 Free Software Foundation, Inc.
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 3 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, see <https://www.gnu.org/licenses/>. */ The GNUv3 license
/* David MacKenzie <djm@gnu.ai.mit.edu> */
#include <config.h> Provides system specific information
#include <stdio.h> Provides standard I/O capability
#include <getopt.h> ...!includes auto-comment...
#include <sys/types.h> Provides system data types
#include "system.h" ...!includes auto-comment...
#if ! HAVE_NICE Line 26
/* Include this after "system.h" so we're sure to have definitions
(from time.h or sys/time.h) required for e.g. the ru_utime member. */
# include <sys/resource.h> ...!includes auto-comment...
#endif Line 30
#include "die.h" ...!includes auto-comment...
#include "error.h" ...!includes auto-comment...
#include "quote.h" ...!includes auto-comment...
#include "xstrtol.h" ...!includes auto-comment...
/* The official name of this program (e.g., no 'g' prefix). */
#define PROGRAM_NAME "nice" Line 38
#define AUTHORS proper_name ("David MacKenzie") Line 40
#if HAVE_NICE Line 42
# define GET_NICENESS() nice (0) Line 43
#else Line 44
# define GET_NICENESS() getpriority (PRIO_PROCESS, 0) Line 45
#endif Line 46
#ifndef NZERO Line 48
# define NZERO 20 Line 49
#endif Line 50
/* This is required for Darwin Kernel Version 7.7.0. */
#if NZERO == 0 Line 53
# undef NZERO Line 54
# define NZERO 20 Line 55
#endif Line 56
static struct option const longopts[] = Line 58
{
{"adjustment", required_argument, NULL, 'n'}, Line 60
{GETOPT_HELP_OPTION_DECL}, Line 61
{GETOPT_VERSION_OPTION_DECL}, Line 62
{NULL, 0, NULL, 0} Line 63
}; Block 1
void Line 66
usage (int status) Line 67
{
if (status != EXIT_SUCCESS) Line 69
emit_try_help (); ...!common auto-comment...
else Line 71
{
printf (_("Usage: %s [OPTION] [COMMAND [ARG]...]\n"), program_name); Line 73
printf (_("\ Line 74
Run COMMAND with an adjusted niceness, which affects process scheduling.\n\ Line 75
With no COMMAND, print the current niceness. Niceness values range from\n\ Line 76
%d (most favorable to the process) to %d (least favorable to the process).\n\ Line 77
"), Line 78
- NZERO, NZERO - 1); Line 79
emit_mandatory_arg_note (); ...!common auto-comment...
fputs (_("\ Line 83
-n, --adjustment=N add integer N to the niceness (default 10)\n\ Line 84
"), stdout); Line 85
fputs (HELP_OPTION_DESCRIPTION, stdout); Line 86
fputs (VERSION_OPTION_DESCRIPTION, stdout); Line 87
printf (USAGE_BUILTIN_WARNING, PROGRAM_NAME); Line 88
emit_ancillary_info (PROGRAM_NAME); Line 89
}
exit (status); Line 91
} Block 2
static bool Line 94
perm_related_errno (int err) Line 95
{
return err == EACCES || err == EPERM; Line 97
} Block 3
int
main (int argc, char **argv) Line 101
{
int current_niceness; Line 103
int adjustment = 10; Line 104
char const *adjustment_given = NULL; Line 105
bool ok; Line 106
int i; Line 107
initialize_main (&argc, &argv); VMS-specific entry point handling wildcard expansion
set_program_name (argv[0]); Retains program name and discards path
setlocale (LC_ALL, ""); Sets up internationalization (i18n)
bindtextdomain (PACKAGE, LOCALEDIR); Assigns i18n directorySets text domain for _() [gettext()] function
textdomain (PACKAGE); Sets text domain for _() [gettext()] function
initialize_exit_failure (EXIT_CANCELED); Line 115
atexit (close_stdout); Close stdout on exit (see gnulib)
for (i = 1; i < argc; /* empty */) Line 118
{
char const *s = argv[i]; Line 120
if (s[0] == '-' && ISDIGIT (s[1 + (s[1] == '-' || s[1] == '+')])) Line 122
{
adjustment_given = s + 1; Line 124
++i; Line 125
}
else Line 127
{
int c; Line 129
int fake_argc = argc - (i - 1); Line 130
char **fake_argv = argv + (i - 1); Line 131
/* Ensure that any getopt diagnostics use the right name. */
fake_argv[0] = argv[0]; Line 134
/* Initialize getopt_long's internal state. */
optind = 0; Line 137
c = getopt_long (fake_argc, fake_argv, "+n:", longopts, NULL); Line 139
i += optind - 1; Line 140
switch (c) Line 142
{
case 'n': Line 144
adjustment_given = optarg; Line 145
break; Line 146
case -1: Line 148
break; Line 149
case_GETOPT_HELP_CHAR; Line 151
case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS); Line 153
default: Line 155
usage (EXIT_CANCELED); Line 156
break; Line 157
}
if (c == -1) Line 160
break; Line 161
}
}
if (adjustment_given) Line 165
{
/* If the requested adjustment is outside the valid range,
silently bring it to just within range; this mimics what
"setpriority" and "nice" do. */
enum { MIN_ADJUSTMENT = 1 - 2 * NZERO, MAX_ADJUSTMENT = 2 * NZERO - 1 }; Line 170
long int tmp; Line 171
if (LONGINT_OVERFLOW < xstrtol (adjustment_given, NULL, 10, &tmp, "")) Line 172
die (EXIT_CANCELED, 0, _("invalid adjustment %s"), Line 173
quote (adjustment_given)); Line 174
adjustment = MAX (MIN_ADJUSTMENT, MIN (tmp, MAX_ADJUSTMENT)); Line 175
}
if (i == argc) Line 178
{
if (adjustment_given) Line 180
{
error (0, 0, _("a command must be given with an adjustment")); Line 182
usage (EXIT_CANCELED); Line 183
}
/* No command given; print the niceness. */
errno = 0; Line 186
current_niceness = GET_NICENESS (); Line 187
if (current_niceness == -1 && errno != 0) Line 188
die (EXIT_CANCELED, errno, _("cannot get niceness")); Line 189
printf ("%d\n", current_niceness); Line 190
return EXIT_SUCCESS; Line 191
}
errno = 0; Line 194
#if HAVE_NICE Line 195
ok = (nice (adjustment) != -1 || errno == 0); Line 196
#else Line 197
current_niceness = GET_NICENESS (); Line 198
if (current_niceness == -1 && errno != 0) Line 199
die (EXIT_CANCELED, errno, _("cannot get niceness")); Line 200
ok = (setpriority (PRIO_PROCESS, 0, current_niceness + adjustment) == 0); Line 201
#endif Line 202
if (!ok) Line 203
{
error (perm_related_errno (errno) ? 0 Line 205
: EXIT_CANCELED, errno, _("cannot set niceness")); Line 206
/* error() flushes stderr, but does not check for write failure.
Normally, we would catch this via our atexit() hook of
close_stdout, but execvp() gets in the way. If stderr
encountered a write failure, there is no need to try calling
error() again. */
if (ferror (stderr)) Line 212
return EXIT_CANCELED; Line 213
}
execvp (argv[i], &argv[i]); Line 216
int exit_status = errno == ENOENT ? EXIT_ENOENT : EXIT_CANNOT_INVOKE; Line 218
error (0, errno, "%s", quote (argv[i])); Line 219
return exit_status; Line 220
} Block 4