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-rw-r--r--src/groups.c145
1 files changed, 145 insertions, 0 deletions
diff --git a/src/groups.c b/src/groups.c
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+++ b/src/groups.c
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+/* groups -- print the groups a user is in
+ Copyright (C) 1989-2022 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/>. */
+
+/* Written by James Youngman based on id.c and groups.sh,
+ which were written by Arnold Robbins and David MacKenzie. */
+
+#include <config.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <pwd.h>
+#include <grp.h>
+#include <getopt.h>
+
+#include "system.h"
+#include "die.h"
+#include "group-list.h"
+#include "quote.h"
+
+/* The official name of this program (e.g., no 'g' prefix). */
+#define PROGRAM_NAME "groups"
+
+#define AUTHORS \
+ proper_name ("David MacKenzie"), \
+ proper_name ("James Youngman")
+
+
+static struct option const longopts[] =
+{
+ {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]... [USERNAME]...\n"), program_name);
+ fputs (_("\
+Print group memberships for each USERNAME or, if no USERNAME is specified, for\
+\n\
+the current process (which may differ if the groups database has changed).\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)
+{
+ int optc;
+ bool ok = true;
+ gid_t rgid, egid;
+ uid_t ruid;
+
+ initialize_main (&argc, &argv);
+ set_program_name (argv[0]);
+ setlocale (LC_ALL, "");
+ bindtextdomain (PACKAGE, LOCALEDIR);
+ textdomain (PACKAGE);
+
+ atexit (close_stdout);
+
+ /* Processing the arguments this way makes groups.c behave differently to
+ * groups.sh if one of the arguments is "--".
+ */
+ while ((optc = getopt_long (argc, argv, "", longopts, NULL)) != -1)
+ {
+ switch (optc)
+ {
+ case_GETOPT_HELP_CHAR;
+ case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
+ default:
+ usage (EXIT_FAILURE);
+ }
+ }
+
+ if (optind == argc)
+ {
+ /* No arguments. Divulge the details of the current process. */
+ uid_t NO_UID = -1;
+ gid_t NO_GID = -1;
+
+ errno = 0;
+ ruid = getuid ();
+ if (ruid == NO_UID && errno)
+ die (EXIT_FAILURE, errno, _("cannot get real UID"));
+
+ errno = 0;
+ egid = getegid ();
+ if (egid == NO_GID && errno)
+ die (EXIT_FAILURE, errno, _("cannot get effective GID"));
+
+ errno = 0;
+ rgid = getgid ();
+ if (rgid == NO_GID && errno)
+ die (EXIT_FAILURE, errno, _("cannot get real GID"));
+
+ if (!print_group_list (NULL, ruid, rgid, egid, true, ' '))
+ ok = false;
+ putchar ('\n');
+ }
+ else
+ {
+ /* At least one argument. Divulge the details of the specified users. */
+ for ( ; optind < argc; optind++)
+ {
+ struct passwd *pwd = getpwnam (argv[optind]);
+ if (pwd == NULL)
+ {
+ error (0, 0, _("%s: no such user"), quote (argv[optind]));
+ ok = false;
+ continue;
+ }
+ ruid = pwd->pw_uid;
+ rgid = egid = pwd->pw_gid;
+
+ printf ("%s : ", argv[optind]);
+ if (!print_group_list (argv[optind], ruid, rgid, egid, true, ' '))
+ ok = false;
+ putchar ('\n');
+ }
+ }
+
+ return ok ? EXIT_SUCCESS : EXIT_FAILURE;
+}