#! /usr/bin/perl -lw
use strict;

use Shell qw(ps);

my $sh = Shell->new;
my @pids =  grep ( $_ =~ /t\.pl/, $sh->ps('aux'));
print "list of running instances:\n@pids\n" ;
for( @pids ) {
    exit if ( $_ && /t\.pl\s.*\-a/ ) ;
}
print "no other instance running\n" ;