my $found = substr $tmp, rindex($tmp, "\n")+1;
print "$found\n";

##</code><code>##

my $tmp = "1: 2\n2: /my/tmp/20160213T161519/outgoing\n3: DL\n4: 0\nTempSource: , Ue: 2, TaskName=, TempDest: \nTaskName \n/data/busybox/ps |grep mgen5| grep -v grep\nDL txt is running PID: 3848\nRunning:Mgen:3848";

my @fields = qw(All Value Name Process_ID);
my %substr;
 
@substr{@fields} = $tmp =~ m/\n(Running:(([^:]+):(\d+)))(?:\D|$)/;
 
printf "%-12s[%s]\n", $_, $substr{$_} for @fields;

##</code><code>##

All         [Running:Mgen:3848]
Value       [Mgen:3848]
Name        [Mgen]
Process_ID  [3848]