release/src/router/busybox/shell/ash_test/printenv.c

   1 /* printenv -- minimal clone of BSD printenv(1).
   2
   3    usage: printenv [varname]
   4
   5    Chet Ramey
   6    chet@po.cwru.edu
   7 */
   8
   9 /* Copyright (C) 1997-2002 Free Software Foundation, Inc.
  10
  11    This file is part of GNU Bash, the Bourne Again SHell.
  12
  13    Bash is free software; you can redistribute it and/or modify it under
  14    the terms of the GNU General Public License as published by the Free
  15    Software Foundation; either version 2, or (at your option) any later
  16    version.
  17
  18    Bash is distributed in the hope that it will be useful, but WITHOUT ANY
  19    WARRANTY; without even the implied warranty of MERCHANTABILITY or
  20    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  21    for more details.
  22
  23    You should have received a copy of the GNU General Public License along
  24    with Bash; see the file COPYING.  If not, write to the Free Software
  25    Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA. */
  26
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29 #include <string.h>
  30
  31 extern char **environ;
  32
  33 int
  34 main (argc, argv)
  35      int argc;
  36      char **argv;
  37 {
  38   register char **envp, *eval;
  39   int len;
  40
  41   argv++;
  42   argc--;
  43
  44   /* printenv */
  45   if (argc == 0)
  46     {
  47       for (envp = environ; *envp; envp++)
  48         puts (*envp);
  49       exit(EXIT_SUCCESS);
  50     }
  51
  52   /* printenv varname */
  53   len = strlen (*argv);
  54   for (envp = environ; *envp; envp++)
  55     {
  56       if (**argv == **envp && strncmp (*envp, *argv, len) == 0)
  57         {
  58           eval = *envp + len;
  59           /* If the environment variable doesn't have an `=', ignore it. */
  60           if (*eval == '=')
  61             {
  62               puts (eval + 1);
  63               exit(EXIT_SUCCESS);
  64             }
  65         }
  66     }
  67   exit(EXIT_FAILURE);
  68 }