I've not always been happy with approaches that parse a whole line when the data I need was in part of the line.

This is a partial line approach:

#!/usr/bin/perl
use warnings;
use strict;
my $file = "My file ";
my $currentInterface = "Cisco Interface X";
while(<DATA>) {
    my $input_drops = 0;
    my $output_drops = 0;
    $input_drops = $1 if ( m{queue:\s+\d+/\d+/(\d+)/\d+} );
    $output_drops = $1 if ( m{drops:\s+(\d+)$} );
    printf("%-20.20s %-22.22s : $.\n",$file,$currentInterface) 
        if ( $input_drops or $output_drops );
}

__DATA__
 Input queue: 0/75/0/39 (size/max/drops/flushes); Total output drops: 
+19845805
[download]

And the output is:

C:\Code>perl regex-test.pl
My file              Cisco Interface X      : 1
[download]