posix/id.c

   1 /* Copyright (C) 1991, 1995 Free Software Foundation, Inc.
   2 This file is part of the GNU C Library.
   3
   4 The GNU C Library is free software; you can redistribute it and/or
   5 modify it under the terms of the GNU Library General Public License as
   6 published by the Free Software Foundation; either version 2 of the
   7 License, or (at your option) any later version.
   8
   9 The GNU C Library 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 GNU
  12 Library General Public License for more details.
  13
  14 You should have received a copy of the GNU Library General Public
  15 License along with the GNU C Library; see the file COPYING.LIB.  If
  16 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  17 Cambridge, MA 02139, USA.  */
  18
  19 #include <ansidecl.h>
  20 #include <stdio.h>
  21 #include <unistd.h>
  22 #include <stdlib.h>
  23 #include <grp.h>
  24 #include <pwd.h>
  25 #include <limits.h>
  26 #include <sys/types.h>
  27
  28
  29 static void
  30 DEFUN(print_grpname, (id, parens),
  31       gid_t id AND int parens)
  32 {
  33   CONST struct group *CONST g = getgrgid(id);
  34   if (g == NULL)
  35     {
  36       if (parens)
  37         return;
  38       else
  39         {
  40           fprintf(stderr, _("Couldn't find name for group %d\n"), id);
  41           exit(EXIT_FAILURE);
  42         }
  43     }
  44
  45   if (parens)
  46     printf("(%s)", g->gr_name);
  47   else
  48     puts(g->gr_name);
  49 }
  50
  51 static void
  52 DEFUN(print_pwdname, (id, parens),
  53       uid_t id AND int parens)
  54 {
  55   CONST struct passwd *CONST p = getpwuid(id);
  56   if (p == NULL)
  57     {
  58       if (parens)
  59         return;
  60       else
  61         {
  62           fprintf(stderr, _("Couldn't find name for user %d\n"), (int) id);
  63           exit(EXIT_FAILURE);
  64         }
  65     }
  66
  67   if (parens)
  68     printf("(%s)", p->pw_name);
  69   else
  70     puts(p->pw_name);
  71 }
  72 \f
  73 int
  74 DEFUN(main, (argc, argv), int argc AND char **argv)
  75 {
  76   int print_gid = 1, print_uid = 1;
  77   int real = 0, name = 0;
  78   int error = 0;
  79   register int c;
  80
  81   uid_t ruid = getuid(), euid = geteuid();
  82   gid_t rgid = getgid(), egid = getegid();
  83
  84   while ((c = getopt(argc, argv, "gurn")) != -1)
  85     switch (c)
  86       {
  87       default:
  88         error = 1;
  89         break;
  90
  91       case 'g':
  92         print_gid = 1;
  93         print_uid = 0;
  94         break;
  95
  96       case 'u':
  97         print_uid = 1;
  98         print_gid = 0;
  99         break;
 100
 101       case 'r':
 102         real = 1;
 103         break;
 104
 105       case 'n':
 106         name = 1;
 107         break;
 108       }
 109
 110   if (error || argc != optind)
 111     {
 112       fputs(_("Usage: id [-gurn]\n"), stderr);
 113       exit(EXIT_FAILURE);
 114     }
 115
 116   if (print_uid && !print_gid)
 117     {
 118       CONST uid_t uid = real ? ruid : euid;
 119       if (name)
 120         print_pwdname(uid, 0);
 121       else
 122         printf("%d\n", (int) uid);
 123     }
 124   else if (print_gid && !print_uid)
 125     {
 126       CONST gid_t gid = real ? rgid : egid;
 127       if (name)
 128         print_grpname(gid, 0);
 129       else
 130         printf("%d\n", (int) gid);
 131     }
 132   else
 133     {
 134 #if     NGROUPS_MAX > 0
 135       gid_t groups[NGROUPS_MAX];
 136       int ngroups;
 137       ngroups = getgroups(NGROUPS_MAX, groups);
 138 #endif
 139
 140       printf("uid=%d", (int) ruid);
 141       print_pwdname(ruid, 1);
 142       printf(" gid=%d", (int) rgid);
 143       print_grpname(rgid, 1);
 144       if (euid != ruid)
 145         {
 146           printf(" euid=%d", (int) euid);
 147           print_pwdname(euid, 1);
 148         }
 149       if (egid != rgid)
 150         {
 151           printf(" egid=%d", (int) egid);
 152           print_grpname(egid, 1);
 153         }
 154
 155 #if     NGROUPS > 0
 156       if (ngroups > 0)
 157         {
 158           register size_t i;
 159           printf(" groups=%d", (int) groups[0]);
 160           print_grpname(groups[0], 1);
 161           for (i = 1; i < ngroups; ++i)
 162             {
 163               printf(", %d", (int) groups[i]);
 164               print_grpname(groups[i], 1);
 165             }
 166         }
 167 #endif
 168
 169       putchar('\n');
 170     }
 171
 172   exit(EXIT_SUCCESS);
 173 }