use Proc::ProcessTable;

my @pids = get_pid( 'httpd' );

sub get_pid
{
    my ( $process ) = @_;

    my @pids = ();
    my $proc = Proc::ProcessTable->new;
    foreach ( @{ $proc->table } ) {
        if ($_->cmndline =~ /$process/) {
            push @pids, $_->pid;
        }
    }
    return @pids;
}