src/group-list.c

   1 /* group-list.c --Print a list of group IDs or names.
   2    Copyright (C) 1989-2011 Free Software Foundation, Inc.
   3
   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 3 of the License, or
   7    (at your option) any later version.
   8
   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.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  16
  17 /* Written by Arnold Robbins.
  18    Major rewrite by David MacKenzie, djm@gnu.ai.mit.edu.
  19    Extracted from id.c by James Youngman. */
  20
  21 #include <config.h>
  22 #include <stdio.h>
  23 #include <sys/types.h>
  24 #include <pwd.h>
  25 #include <grp.h>
  26
  27 #include "system.h"
  28 #include "error.h"
  29 #include "mgetgroups.h"
  30 #include "quote.h"
  31 #include "group-list.h"
  32
  33
  34 /* Print all of the distinct groups the user is in. */
  35 extern bool
  36 print_group_list (const char *username,
  37                   uid_t ruid, gid_t rgid, gid_t egid,
  38                   bool use_names)
  39 {
  40   bool ok = true;
  41   struct passwd *pwd;
  42
  43   pwd = getpwuid (ruid);
  44   if (pwd == NULL)
  45     ok = false;
  46
  47   if (!print_group (rgid, use_names))
  48     ok = false;
  49
  50   if (egid != rgid)
  51     {
  52       putchar (' ');
  53       if (!print_group (egid, use_names))
  54         ok = false;
  55     }
  56
  57   {
  58     gid_t *groups;
  59     int i;
  60
  61     int n_groups = xgetgroups (username, (pwd ? pwd->pw_gid : (gid_t) -1),
  62                                &groups);
  63     if (n_groups < 0)
  64       {
  65         if (username)
  66           {
  67             error (0, errno, _("failed to get groups for user %s"),
  68                    quote (username));
  69           }
  70         else
  71           {
  72             error (0, errno, _("failed to get groups for the current process"));
  73           }
  74         return false;
  75       }
  76
  77     for (i = 0; i < n_groups; i++)
  78       if (groups[i] != rgid && groups[i] != egid)
  79         {
  80           putchar (' ');
  81           if (!print_group (groups[i], use_names))
  82             ok = false;
  83         }
  84     free (groups);
  85   }
  86   return ok;
  87 }
  88
  89
  90 /* Print the name or value of group ID GID. */
  91 extern bool
  92 print_group (gid_t gid, bool use_name)
  93 {
  94   struct group *grp = NULL;
  95   bool ok = true;
  96
  97   if (use_name)
  98     {
  99       grp = getgrgid (gid);
 100       if (grp == NULL)
 101         {
 102           error (0, 0, _("cannot find name for group ID %lu"),
 103                  (unsigned long int) gid);
 104           ok = false;
 105         }
 106     }
 107
 108   if (grp == NULL)
 109     printf ("%lu", (unsigned long int) gid);
 110   else
 111     printf ("%s", grp->gr_name);
 112   return ok;
 113 }