use strict;
use warnings;

#open files here

#my $counter = 0;
my @slotarray;

while ( <DPSLOTFILE> ) {
    my $dpdrivloc = "MSL6000 Trinity";
    if ( /\Q$dpdrivloc\E:\s*(\d+)/ ) {
        #my $slotarray{$counter} = "$1";
        #print OUTFILE "$1";
        #$counter++;

        push @slotarray, $1;
    }
}

for (@slotarray) {
   #print OUTFILE "$slotarray\n";
    print OUTFILE $_,$/;
}
#close files here

##</code><code>##

for my $slotarray (@slotarray) {
 print OUTFILE "$slotarray\n";
}

##</code><code>##

while (<DPSLOTFILE>){
  next unless /\QMSL6000 Trinity:\s*(\d+)/;
  print OUTFILE $1,$/;
}
##</code><code>##

perl -nle 'print $1,$/ if /\QQMSL6000 Trinity:\s*(\d+)/' input_file > output_file;