/* id -- print real and effective UIDs and GIDs Copyright (C) 89, 90, 91, 92, 93, 94, 1995 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 2, 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, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ /* Written by Arnold Robbins, arnold@audiofax.com. Major rewrite by David MacKenzie, djm@gnu.ai.mit.edu. */ #include #include #include #include #include #include #include #include "version.h" #include "system.h" #include "error.h" #ifdef _POSIX_VERSION #include #if !defined(NGROUPS_MAX) || NGROUPS_MAX < 1 #undef NGROUPS_MAX #define NGROUPS_MAX sysconf (_SC_NGROUPS_MAX) #endif /* !NGROUPS_MAX */ #else /* not _POSIX_VERSION */ struct passwd *getpwuid (); struct group *getgrgid (); uid_t getuid (); gid_t getgid (); uid_t geteuid (); gid_t getegid (); #include #if !defined(NGROUPS_MAX) && defined(NGROUPS) #define NGROUPS_MAX NGROUPS #endif /* not NGROUPS_MAX and NGROUPS */ #endif /* not _POSIX_VERSION */ char *xmalloc (); int getugroups (); static void print_user (); static void print_group (); static void print_group_list (); static void print_full_info (); static void usage (); /* The name this program was run with. */ char *program_name; /* If nonzero, output only the group ID(s). -g */ static int just_group = 0; /* If nonzero, output user/group name instead of ID number. -n */ static int use_name = 0; /* If nonzero, output real UID/GID instead of default effective UID/GID. -r */ static int use_real = 0; /* If nonzero, output only the user ID(s). -u */ static int just_user = 0; /* If nonzero, output only the supplementary groups. -G */ static int just_group_list = 0; /* The real and effective IDs of the user to print. */ static uid_t ruid, euid; static gid_t rgid, egid; /* The number of errors encountered so far. */ static int problems = 0; /* If nonzero, display usage information and exit. */ static int show_help; /* If nonzero, print the version on standard output and exit. */ static int show_version; static struct option const longopts[] = { {"group", no_argument, NULL, 'g'}, {"groups", no_argument, NULL, 'G'}, {"help", no_argument, &show_help, 1}, {"name", no_argument, NULL, 'n'}, {"real", no_argument, NULL, 'r'}, {"user", no_argument, NULL, 'u'}, {"version", no_argument, &show_version, 1}, {NULL, 0, NULL, 0} }; void main (argc, argv) int argc; char **argv; { int optc; program_name = argv[0]; while ((optc = getopt_long (argc, argv, "gnruG", longopts, (int *) 0)) != EOF) { switch (optc) { case 0: break; case 'g': just_group = 1; break; case 'n': use_name = 1; break; case 'r': use_real = 1; break; case 'u': just_user = 1; break; case 'G': just_group_list = 1; break; default: usage (1); } } if (show_version) { printf ("id - %s\n", version_string); exit (0); } if (show_help) usage (0); if (just_user + just_group + just_group_list > 1) error (1, 0, _("cannot print only user and only group")); if (just_user + just_group + just_group_list == 0 && (use_real || use_name)) error (1, 0, _("cannot print only names or real IDs in default format")); if (argc - optind > 1) usage (1); if (argc - optind == 1) { struct passwd *pwd = getpwnam (argv[optind]); if (pwd == NULL) error (1, 0, _("%s: No such user"), argv[optind]); ruid = euid = pwd->pw_uid; rgid = egid = pwd->pw_gid; } else { euid = geteuid (); ruid = getuid (); egid = getegid (); rgid = getgid (); } if (just_user) print_user (use_real ? ruid : euid); else if (just_group) print_group (use_real ? rgid : egid); else if (just_group_list) print_group_list (argv[optind]); else print_full_info (argv[optind]); putchar ('\n'); exit (problems != 0); } /* Print the name or value of user ID UID. */ static void print_user (uid) int uid; { struct passwd *pwd = NULL; if (use_name) { pwd = getpwuid (uid); if (pwd == NULL) problems++; } if (pwd == NULL) printf ("%u", (unsigned) uid); else printf ("%s", pwd->pw_name); } /* Print the name or value of group ID GID. */ static void print_group (gid) int gid; { struct group *grp = NULL; if (use_name) { grp = getgrgid (gid); if (grp == NULL) problems++; } if (grp == NULL) printf ("%u", (unsigned) gid); else printf ("%s", grp->gr_name); } /* Print all of the distinct groups the user is in . */ static void print_group_list (username) char *username; { print_group (rgid); if (egid != rgid) { putchar (' '); print_group (egid); } #if defined(NGROUPS_MAX) && defined(HAVE_GETGROUPS) { int ngroups; GETGROUPS_T *groups; register int i; groups = (GETGROUPS_T *) xmalloc (NGROUPS_MAX * sizeof (GETGROUPS_T)); if (username == 0) ngroups = getgroups (NGROUPS_MAX, groups); else ngroups = getugroups (NGROUPS_MAX, groups, username); if (ngroups < 0) { error (0, errno, _("cannot get supplemental group list")); problems++; free (groups); return; } for (i = 0; i < ngroups; i++) if (groups[i] != rgid && groups[i] != egid) { putchar (' '); print_group (groups[i]); } free (groups); } #endif } /* Print all of the info about the user's user and group IDs. */ static void print_full_info (username) char *username; { struct passwd *pwd; struct group *grp; printf ("uid=%u", (unsigned) ruid); pwd = getpwuid (ruid); if (pwd == NULL) problems++; else printf ("(%s)", pwd->pw_name); printf (" gid=%u", (unsigned) rgid); grp = getgrgid (rgid); if (grp == NULL) problems++; else printf ("(%s)", grp->gr_name); if (euid != ruid) { printf (" euid=%u", (unsigned) euid); pwd = getpwuid (euid); if (pwd == NULL) problems++; else printf ("(%s)", pwd->pw_name); } if (egid != rgid) { printf (" egid=%u", (unsigned) egid); grp = getgrgid (egid); if (grp == NULL) problems++; else printf ("(%s)", grp->gr_name); } #if defined(NGROUPS_MAX) && defined(HAVE_GETGROUPS) { int ngroups; GETGROUPS_T *groups; register int i; groups = (GETGROUPS_T *) xmalloc (NGROUPS_MAX * sizeof (GETGROUPS_T)); if (username == 0) ngroups = getgroups (NGROUPS_MAX, groups); else ngroups = getugroups (NGROUPS_MAX, groups, username); if (ngroups < 0) { error (0, errno, _("cannot get supplemental group list")); problems++; free (groups); return; } if (ngroups > 0) fputs (_(" groups="), stdout); for (i = 0; i < ngroups; i++) { if (i > 0) putchar (','); printf ("%u", (unsigned) groups[i]); grp = getgrgid (groups[i]); if (grp == NULL) problems++; else printf ("(%s)", grp->gr_name); } free (groups); } #endif } static void usage (status) int status; { if (status != 0) fprintf (stderr, _("Try `%s --help' for more information.\n"), program_name); else { printf (_("Usage: %s [OPTION]... [USERNAME]\n"), program_name); printf (_("\ Print information for USERNAME, or the current user.\n\ \n\ -g, --group print only the group ID\n\ -G, --groups print only the supplementary groups\n\ -n, --name print a name instead of a number, for -ugG\n\ -r, --real print the real ID instead of effective ID, for -ugG\n\ -u, --user print only the user ID\n\ --help display this help and exit\n\ --version output version information and exit\n\ \n\ Without any OPTION, print some useful set of identified information.\n\ ")); } exit (status); }