#!/usr/bin/perl -w

use strict;

my $process = "perl";
my @output;
my $kidpid;

if ($kidpid = open(PIPE, "-|")) {
 # Parent process.  Read data from the child.
 @output = <PIPE>;
} else {
 # Child process.  Execute the command.
 die "could not fork" if !defined($kidpid);
 exec ("ps", "-ef", "|", "grep", $process) or die "exec failed: $!";
}