source: vendor/bash/3.1/support/printenv.c

/* printenv -- minimal clone of BSD printenv(1).

   usage: printenv [varname]

   Chet Ramey
   chet@po.cwru.edu
*/

/* Copyright (C) 1997-2002 Free Software Foundation, Inc.

   This file is part of GNU Bash, the Bourne Again SHell.

   Bash is free software; you can redistribute it and/or modify it under
   the terms of the GNU General Public License as published by the Free
   Software Foundation; either version 2, or (at your option) any later
   version.

   Bash is distributed in the hope that it will be useful, but WITHOUT ANY
   WARRANTY; without even the implied warranty of MERCHANTABILITY or
   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   for more details.

   You should have received a copy of the GNU General Public License along
   with Bash; see the file COPYING.  If not, write to the Free Software
   Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA. */

#if defined (HAVE_CONFIG_H)
#  include  <config.h>
#endif

#include "bashansi.h"

extern char **environ;

int
main (argc, argv) 
     int argc;
     char **argv;
{
  register char **envp, *eval;
  int len;

  argv++;
  argc--;

  /* printenv */
  if (argc == 0)
    {
      for (envp = environ; *envp; envp++)
        puts (*envp);
      exit (0);
    }

  /* printenv varname */
  len = strlen (*argv);
  for (envp = environ; *envp; envp++)
    {
      if (**argv == **envp && strncmp (*envp, *argv, len) == 0)
        {
          eval = *envp + len;
          /* If the environment variable doesn't have an `=', ignore it. */
          if (*eval == '=')
            {
              puts (eval + 1);
              exit (0);
            }
        }
    }
  exit (1);
}