my @args = map{ ($_, foo($arg{$_})) } keys %args;
    my @output = `/bin/foo @args`;

##</code><code>##

  system( '/bin/foo    -p    stuff' ); # passes by the shell
  system( '/bin/foo', '-p', 'stuff' ); # bypasses the shell

##</code><code>##

  my @out = `/bin/foo`, qw/-p stuff/;

##</code><code>##

my $pid;
if( !defined($pid = open( KIDP, '-|' ))) {
    print child fork error: $!\n";
}
elsif( $pid ) {
    while( <KID> ) {
        chomp;
        # digest $_
    }
    close KID;
}
else {
     $ENV{PATH} = '/bin:/usr/bin:/usr/local/bin';
     my @args = map{ (foo, foo($_)) } keys %data;
     exec '/usr/local/bin/check-netscreen', @args;
     die "ping child died \$!=$! \$@=$@\nargs = @args";
}

##</code><code>##

#! /usr/bin/perl -w

use strict;

my @out = readpipe( '/bin/foo', qw/one two three/ );