#include <stdlib.h>
#include <stdio.h>

int main( int argc, char **argv ) {
  char *arg = *++argv;
  printf( "%s is %s\n", arg, getenv(arg) );
  exit(0);
}

##</code><code>##

#! /usr/bin/perl -w

use strict;

my $var   = shift || 'FOO';
my $value = shift || 'bar';

$ENV{$var} = $value;
system "./env-echo $var";