#!/opt/bin/perl

use Getopt::Long;
use PApp::Env;

$unset = 0;

sub printval {
   my $val = shift;
   if (ref $val) {
      print "{$val}\n";
   } else {
      print "$val\n";
   }
}

Getopt::Long::Configure ("bundling", "no_ignore_case");

if (@ARGV) {
   GetOptions(
            "help|h" => sub {
               require Pod::Usage;
               Pod::Usage::pod2usage(1);
            },
            "unset|u" => sub {
               $unset = 1;
            },
            "eval|e" => sub {
               $eval = 1;
            },
            "<>" => sub {
               if ($_[0] =~ /^([^=]+)=(.*)$/s) {
                  my ($var, $val) = ($1, $2);
                  if ($eval) {
                     my $_val = $val;
                     $val = eval $_val;
                     die "$var=$_val: $@\n" if $@;
                  }
                  setenv $var, $val;
               } elsif ($unset) {
                  unsetenv $_[0];
               } else {
                  printval getenv $_[0];
               }
            },

   );
} else {
   for (listenv) {
      print "$_=";
      printval getenv($_);
   }
}

=head1 NAME

papp-env - get/set/clear/display environment variables

=head1 SYNOPSIS

   papp-env --help

List all environment variables in name=value format (I<warning>, might
contain binary data):

   papp-env

List the value of a single environment variable (I<without> trailing newline):

   papp-env myvar

Set some env-variables:

   papp-env var1=value1 var2=value2 "var3=value 3" var4="contains == equal!"

Unsetting instead of setting env-variables:
 
   papp-env -u var1 var2 var3

Combine almost all of the above:

   papp-env var=value printvar1 -u v2 v3 v4

Evaluate value as perl code rather than as strings:

   papp-env -e arrayvar="['val1', 'val2']" hashvar="{ a => 5, b => 7}"

=head1 DESCRIPTION

This program is used to query and set PApp environment variables.

Settings that are associated with specific PApp applications often can be
used in PApp environment variables.

Environment variables are also useful for asynchronous communication
between PApp applications and outside apps.

=head1 SEE ALSO

L<PApp>.

=head1 BUGS

- no handling of binary data or perl-structures

=head1 AUTHOR

 Marc Lehmann <schmorp@schmorp.de>
 http://www.goof.com/pcg/marc/

=cut