examples/loadables/logname.c

   1 /* logname - print login name of current user */
   2
   3 /*
   4    Copyright (C) 1999-2009 Free Software Foundation, Inc.
   5
   6    This file is part of GNU Bash.
   7    Bash is free software: you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation, either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    Bash is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with Bash.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include <config.h>
  22
  23 #if defined (HAVE_UNISTD_H)
  24 #  include <unistd.h>
  25 #endif
  26
  27 #include <stdio.h>
  28 #include <errno.h>
  29
  30 #include "builtins.h"
  31 #include "shell.h"
  32 #include "common.h"
  33
  34 #if !defined (errno)
  35 extern int errno;
  36 #endif
  37
  38 logname_builtin (list)
  39      WORD_LIST *list;
  40 {
  41   char *np;
  42
  43   if (no_options (list))
  44     return (EX_USAGE);
  45
  46   np = getlogin ();
  47   if (np == 0)
  48     {
  49       builtin_error ("cannot find username: %s", strerror (errno));
  50       return (EXECUTION_FAILURE);
  51     }
  52   printf ("%s\n", np);
  53   return (EXECUTION_SUCCESS);
  54 }
  55
  56 char *logname_doc[] = {
  57         "Display user login name.",
  58         "",
  59         "Write the current user's login name to the standard output",
  60         "and exit.  logname ignores the LOGNAME and USER variables.",
  61         "logname ignores any non-option arguments.",
  62         (char *)NULL
  63 };
  64
  65 struct builtin logname_struct = {
  66         "logname",
  67         logname_builtin,
  68         BUILTIN_ENABLED,
  69         logname_doc,
  70         "logname",
  71         0
  72 };
  73