src/logname.c

   1 /* logname -- print user's login name
   2    Copyright (C) 1990-1997, 1999 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 2, or (at your option)
   7    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, write to the Free Software Foundation,
  16    Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  17
  18 #include <config.h>
  19 #include <stdio.h>
  20 #include <sys/types.h>
  21 #include <getopt.h>
  22
  23 #include "system.h"
  24 #include "long-options.h"
  25
  26 /* The official name of this program (e.g., no `g' prefix).  */
  27 #define PROGRAM_NAME "logname"
  28
  29 #define AUTHORS "FIXME: unknown"
  30
  31 /* The name this program was run with. */
  32 char *program_name;
  33
  34 static struct option const long_options[] =
  35 {
  36   {0, 0, 0, 0}
  37 };
  38
  39 void
  40 usage (int status)
  41 {
  42   if (status != 0)
  43     fprintf (stderr, _("Try `%s --help' for more information.\n"),
  44              program_name);
  45   else
  46     {
  47       printf (_("Usage: %s [OPTION]...\n"), program_name);
  48       printf (_("\
  49 Print the name of the current user.\n\
  50 \n\
  51   --help      display this help and exit\n\
  52   --version   output version information and exit\n\
  53 "));
  54       puts (_("\nReport bugs to <bug-sh-utils@gnu.org>."));
  55     }
  56   exit (status);
  57 }
  58
  59 int
  60 main (int argc, char **argv)
  61 {
  62   register char *cp;
  63   int c;
  64
  65   program_name = argv[0];
  66   setlocale (LC_ALL, "");
  67   bindtextdomain (PACKAGE, LOCALEDIR);
  68   textdomain (PACKAGE);
  69
  70   parse_long_options (argc, argv, PROGRAM_NAME, GNU_PACKAGE, VERSION,
  71                       AUTHORS, usage);
  72
  73   while ((c = getopt_long (argc, argv, "", long_options, NULL)) != -1)
  74     {
  75       switch (c)
  76         {
  77         case 0:
  78           break;
  79
  80         default:
  81           usage (1);
  82         }
  83     }
  84
  85   if (argc - optind != 0)
  86     usage (1);
  87
  88   /* POSIX.2 requires using getlogin (or equivalent code).  */
  89   cp = getlogin ();
  90   if (cp)
  91     {
  92       puts (cp);
  93       exit (0);
  94     }
  95   /* POSIX.2 prohibits using a fallback technique.  */
  96   fprintf (stderr, _("%s: no login name\n"), argv[0]);
  97   exit (1);
  98 }