my $status = qx{ssh r01mn1 /etc/init.d/hadoop-0.20-mapreduce-jobtracker status | awk '{print $3}'};
print "$status is status of service";
if ( "$status" eq "stopped" )
{
print " JOBTRACKER SERVICE is not running";
}

output
[root@r01mgt ~]# perl testscript.pl
jobtracker is stopped
 is status of service

SHELL COMMAND 
[root@r01mgt ~]# ssh r01mn1 /etc/init.d/hadoop-0.20-mapreduce-jobtracker status | awk '{print $3}'
stopped