1 /* id -- print real and effective UIDs and GIDs
2 Copyright (C) 1989-2003 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 2, or (at your option)
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, write to the Free Software Foundation,
16 Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
18 /* Written by Arnold Robbins.
19 Major rewrite by David MacKenzie, djm@gnu.ai.mit.edu. */
24 #include <sys/types.h>
32 /* The official name of this program (e.g., no `g' prefix). */
33 #define PROGRAM_NAME "id"
35 #define WRITTEN_BY _("Written by Arnold Robbins and David MacKenzie.")
37 #ifndef _POSIX_VERSION
38 struct passwd *getpwuid ();
39 struct group *getgrgid ();
44 #endif /* not _POSIX_VERSION */
48 static void print_user (uid_t uid);
49 static void print_group (gid_t gid);
50 static void print_group_list (const char *username);
51 static void print_full_info (const char *username);
53 /* The name this program was run with. */
56 /* If nonzero, output user/group name instead of ID number. -n */
57 static int use_name = 0;
59 /* The real and effective IDs of the user to print. */
60 static uid_t ruid, euid;
61 static gid_t rgid, egid;
63 /* The number of errors encountered so far. */
64 static int problems = 0;
66 static struct option const longopts[] =
68 {"group", no_argument, NULL, 'g'},
69 {"groups", no_argument, NULL, 'G'},
70 {"name", no_argument, NULL, 'n'},
71 {"real", no_argument, NULL, 'r'},
72 {"user", no_argument, NULL, 'u'},
73 {GETOPT_HELP_OPTION_DECL},
74 {GETOPT_VERSION_OPTION_DECL},
82 fprintf (stderr, _("Try `%s --help' for more information.\n"),
86 printf (_("Usage: %s [OPTION]... [USERNAME]\n"), program_name);
88 Print information for USERNAME, or the current user.\n\
90 -a ignore, for compatibility with other versions\n\
91 -g, --group print only the effective group ID\n\
92 -G, --groups print all group IDs\n\
93 -n, --name print a name instead of a number, for -ugG\n\
94 -r, --real print the real ID instead of the effective ID, with -ugG\n\
95 -u, --user print only the effective user ID\n\
97 fputs (HELP_OPTION_DESCRIPTION, stdout);
98 fputs (VERSION_OPTION_DESCRIPTION, stdout);
101 Without any OPTION, print some useful set of identified information.\n\
103 printf (_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
109 main (int argc, char **argv)
113 /* If nonzero, output the list of all group IDs. -G */
114 int just_group_list = 0;
115 /* If nonzero, output only the group ID(s). -g */
117 /* If nonzero, output real UID/GID instead of default effective UID/GID. -r */
119 /* If nonzero, output only the user ID(s). -u */
122 initialize_main (&argc, &argv);
123 program_name = argv[0];
124 setlocale (LC_ALL, "");
125 bindtextdomain (PACKAGE, LOCALEDIR);
126 textdomain (PACKAGE);
128 atexit (close_stdout);
130 while ((optc = getopt_long (argc, argv, "agnruG", longopts, NULL)) != -1)
137 /* Ignore -a, for compatibility with SVR4. */
154 case_GETOPT_HELP_CHAR;
155 case_GETOPT_VERSION_CHAR (PROGRAM_NAME, WRITTEN_BY);
157 usage (EXIT_FAILURE);
161 if (just_user + just_group + just_group_list > 1)
162 error (EXIT_FAILURE, 0, _("cannot print only user and only group"));
164 if (just_user + just_group + just_group_list == 0 && (use_real || use_name))
165 error (EXIT_FAILURE, 0,
166 _("cannot print only names or real IDs in default format"));
168 if (argc - optind > 1)
169 usage (EXIT_FAILURE);
171 if (argc - optind == 1)
173 struct passwd *pwd = getpwnam (argv[optind]);
175 error (EXIT_FAILURE, 0, _("%s: No such user"), argv[optind]);
176 ruid = euid = pwd->pw_uid;
177 rgid = egid = pwd->pw_gid;
188 print_user (use_real ? ruid : euid);
190 print_group (use_real ? rgid : egid);
191 else if (just_group_list)
192 print_group_list (argv[optind]);
194 print_full_info (argv[optind]);
197 exit (problems != 0);
200 /* Print the name or value of user ID UID. */
203 print_user (uid_t uid)
205 struct passwd *pwd = NULL;
209 pwd = getpwuid (uid);
212 error (0, 0, _("cannot find name for user ID %u"), uid);
218 printf ("%u", (unsigned) uid);
220 printf ("%s", pwd->pw_name);
223 /* Print the name or value of group ID GID. */
226 print_group (gid_t gid)
228 struct group *grp = NULL;
232 grp = getgrgid (gid);
235 error (0, 0, _("cannot find name for group ID %u"), gid);
241 printf ("%u", (unsigned) gid);
243 printf ("%s", grp->gr_name);
248 /* FIXME: document */
251 xgetgroups (const char *username, gid_t gid, int *n_groups,
252 GETGROUPS_T **groups)
260 max_n_groups = getgroups (0, NULL);
262 max_n_groups = getugroups (0, NULL, username, gid);
264 /* Add 1 just in case max_n_groups is zero. */
265 g = xmalloc (max_n_groups * sizeof (GETGROUPS_T) + 1);
267 ng = getgroups (max_n_groups, g);
269 ng = getugroups (max_n_groups, g, username, gid);
273 error (0, errno, _("cannot get supplemental group list"));
285 #endif /* HAVE_GETGROUPS */
287 /* Print all of the distinct groups the user is in. */
290 print_group_list (const char *username)
294 pwd = getpwuid (ruid);
311 if (xgetgroups (username, (pwd ? pwd->pw_gid : (gid_t) -1),
318 for (i = 0; i < n_groups; i++)
319 if (groups[i] != rgid && groups[i] != egid)
322 print_group (groups[i]);
326 #endif /* HAVE_GETGROUPS */
329 /* Print all of the info about the user's user and group IDs. */
332 print_full_info (const char *username)
337 printf ("uid=%u", (unsigned) ruid);
338 pwd = getpwuid (ruid);
342 printf ("(%s)", pwd->pw_name);
344 printf (" gid=%u", (unsigned) rgid);
345 grp = getgrgid (rgid);
349 printf ("(%s)", grp->gr_name);
353 printf (" euid=%u", (unsigned) euid);
354 pwd = getpwuid (euid);
358 printf ("(%s)", pwd->pw_name);
363 printf (" egid=%u", (unsigned) egid);
364 grp = getgrgid (egid);
368 printf ("(%s)", grp->gr_name);
377 if (xgetgroups (username, (pwd ? pwd->pw_gid : (gid_t) -1),
385 fputs (_(" groups="), stdout);
386 for (i = 0; i < n_groups; i++)
390 printf ("%u", (unsigned) groups[i]);
391 grp = getgrgid (groups[i]);
395 printf ("(%s)", grp->gr_name);
399 #endif /* HAVE_GETGROUPS */