[root@localhost ~]# time cat 5000 |perl check.pl  >/tmp/b
 
real    5m59.953s
user    5m59.956s
sys     0m0.105s
[root@localhost ~]# time cat 5000 |perl check1.pl  >/tmp/a
 
real    0m0.134s
user    0m0.111s
sys     0m0.030s

#!/usr/bin/perl
use strict;
use warnings;
 
open A,"<a>){
        my ($md5,$ip) = split;
        $hash{$md5} = $ip;
}
while (<>){
    my $line = $_;
    if( /http:\/\/[\w.]+\/\d+\/(\w+)\// ){
        if( exists $hash{$1}){
            print $line."\n";
        }
    }
}
</a>

<a>#!/usr/bin/perl
use strict;
use warnings;
 
open A,"</a><a>){
        my ($md5,$ip) = split;
            $hash{$md5} = $ip;
        }
while (<>){
   my $line = $_;
      foreach my $md5 ( keys %hash){
              if($line =~ /$md5/){
                    print $line."\n";
                }
      }
}
</a>