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/* nice -- run a program with modified niceness
Copyright (C) 1990-2017 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 <http://www.gnu.org/licenses/>. */
/* David MacKenzie <djm@gnu.ai.mit.edu> */
#include <config.h>
#include <stdio.h>
#include <getopt.h>
#include <sys/types.h>
#include "system.h"
#if ! HAVE_NICE
/* 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>
#endif
#include "die.h"
#include "error.h"
#include "quote.h"
#include "xstrtol.h"
/* The official name of this program (e.g., no 'g' prefix). */
#define PROGRAM_NAME "nice"
#define AUTHORS proper_name ("David MacKenzie")
#if HAVE_NICE
# define GET_NICENESS() nice (0)
#else
# define GET_NICENESS() getpriority (PRIO_PROCESS, 0)
#endif
#ifndef NZERO
# define NZERO 20
#endif
/* This is required for Darwin Kernel Version 7.7.0. */
#if NZERO == 0
# undef NZERO
# define NZERO 20
#endif
static struct option const longopts[] =
{
{"adjustment", required_argument, NULL, 'n'},
{GETOPT_HELP_OPTION_DECL},
{GETOPT_VERSION_OPTION_DECL},
{NULL, 0, NULL, 0}
};
void
usage (int status)
{
if (status != EXIT_SUCCESS)
emit_try_help ();
else
{
printf (_("Usage: %s [OPTION] [COMMAND [ARG]...]\n"), program_name);
printf (_("\
Run COMMAND with an adjusted niceness, which affects process scheduling.\n\
With no COMMAND, print the current niceness. Niceness values range from\n\
%d (most favorable to the process) to %d (least favorable to the process).\n\
"),
- NZERO, NZERO - 1);
emit_mandatory_arg_note ();
fputs (_("\
-n, --adjustment=N add integer N to the niceness (default 10)\n\
"), stdout);
fputs (HELP_OPTION_DESCRIPTION, stdout);
fputs (VERSION_OPTION_DESCRIPTION, stdout);
printf (USAGE_BUILTIN_WARNING, PROGRAM_NAME);
emit_ancillary_info (PROGRAM_NAME);
}
exit (status);
}
static bool
perm_related_errno (int err)
{
return err == EACCES || err == EPERM;
}
int
main (int argc, char **argv)
{
int current_niceness;
int adjustment = 10;
char const *adjustment_given = NULL;
bool ok;
int i;
initialize_main (&argc, &argv);
set_program_name (argv[0]);
setlocale (LC_ALL, "");
bindtextdomain (PACKAGE, LOCALEDIR);
textdomain (PACKAGE);
initialize_exit_failure (EXIT_CANCELED);
atexit (close_stdout);
for (i = 1; i < argc; /* empty */)
{
char const *s = argv[i];
if (s[0] == '-' && ISDIGIT (s[1 + (s[1] == '-' || s[1] == '+')]))
{
adjustment_given = s + 1;
++i;
}
else
{
int c;
int fake_argc = argc - (i - 1);
char **fake_argv = argv + (i - 1);
/* Ensure that any getopt diagnostics use the right name. */
fake_argv[0] = argv[0];
/* Initialize getopt_long's internal state. */
optind = 0;
c = getopt_long (fake_argc, fake_argv, "+n:", longopts, NULL);
i += optind - 1;
switch (c)
{
case 'n':
adjustment_given = optarg;
break;
case -1:
break;
case_GETOPT_HELP_CHAR;
case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
default:
usage (EXIT_CANCELED);
break;
}
if (c == -1)
break;
}
}
if (adjustment_given)
{
/* 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 };
long int tmp;
if (LONGINT_OVERFLOW < xstrtol (adjustment_given, NULL, 10, &tmp, ""))
die (EXIT_CANCELED, 0, _("invalid adjustment %s"),
quote (adjustment_given));
adjustment = MAX (MIN_ADJUSTMENT, MIN (tmp, MAX_ADJUSTMENT));
}
if (i == argc)
{
if (adjustment_given)
{
error (0, 0, _("a command must be given with an adjustment"));
usage (EXIT_CANCELED);
}
/* No command given; print the niceness. */
errno = 0;
current_niceness = GET_NICENESS ();
if (current_niceness == -1 && errno != 0)
die (EXIT_CANCELED, errno, _("cannot get niceness"));
printf ("%d\n", current_niceness);
return EXIT_SUCCESS;
}
errno = 0;
#if HAVE_NICE
ok = (nice (adjustment) != -1 || errno == 0);
#else
current_niceness = GET_NICENESS ();
if (current_niceness == -1 && errno != 0)
die (EXIT_CANCELED, errno, _("cannot get niceness"));
ok = (setpriority (PRIO_PROCESS, 0, current_niceness + adjustment) == 0);
#endif
if (!ok)
{
error (perm_related_errno (errno) ? 0
: EXIT_CANCELED, errno, _("cannot set niceness"));
/* 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))
return EXIT_CANCELED;
}
execvp (argv[i], &argv[i]);
int exit_status = errno == ENOENT ? EXIT_ENOENT : EXIT_CANNOT_INVOKE;
error (0, errno, "%s", quote (argv[i]));
return exit_status;
}
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