Permalink
Branch: master
Find file Copy path
Fetching contributors…
Cannot retrieve contributors at this time
98 lines (80 sloc) 2.48 KB
/* whoami -- print effective userid
Copyright (C) 1989-2019 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/>. */
/* Equivalent to 'id -un'. */
/* Written by Richard Mlynarik. */
#include <config.h>
#include <stdio.h>
#include <sys/types.h>
#include <pwd.h>
#include <getopt.h>
#include "system.h"
#include "die.h"
#include "error.h"
#include "long-options.h"
#include "quote.h"
/* The official name of this program (e.g., no 'g' prefix). */
#define PROGRAM_NAME "whoami"
#define AUTHORS proper_name ("Richard Mlynarik")
static struct option const long_options[] =
{
{NULL, 0, NULL, 0}
};
void
usage (int status)
{
if (status != EXIT_SUCCESS)
emit_try_help ();
else
{
printf (_("Usage: %s [OPTION]...\n"), program_name);
fputs (_("\
Print the user name associated with the current effective user ID.\n\
Same as id -un.\n\
\n\
"), stdout);
fputs (HELP_OPTION_DESCRIPTION, stdout);
fputs (VERSION_OPTION_DESCRIPTION, stdout);
emit_ancillary_info (PROGRAM_NAME);
}
exit (status);
}
int
main (int argc, char **argv)
{
struct passwd *pw;
uid_t uid;
uid_t NO_UID = -1;
initialize_main (&argc, &argv);
set_program_name (argv[0]);
setlocale (LC_ALL, "");
bindtextdomain (PACKAGE, LOCALEDIR);
textdomain (PACKAGE);
atexit (close_stdout);
parse_long_options (argc, argv, PROGRAM_NAME, PACKAGE_NAME, Version,
usage, AUTHORS, (char const *) NULL);
if (getopt_long (argc, argv, "", long_options, NULL) != -1)
usage (EXIT_FAILURE);
if (optind != argc)
{
error (0, 0, _("extra operand %s"), quote (argv[optind]));
usage (EXIT_FAILURE);
}
errno = 0;
uid = geteuid ();
pw = (uid == NO_UID && errno ? NULL : getpwuid (uid));
if (!pw)
die (EXIT_FAILURE, errno, _("cannot find name for user ID %lu"),
(unsigned long int) uid);
puts (pw->pw_name);
return EXIT_SUCCESS;
}