You're compiling the same regular expressions over and over again, once for every line in the second file. Note the use of qr// below.

#!/usr/bin/perl -w

use strict;

my @regexps;

{
   my $fn = $ARGV[0];
   open(my $fh, '<', $fn)
      or die "Cannot open pattern file \"$fn\": $!\n";

   while( <$fh> ) {
      chomp; 
      my ($pat) = /(\S+)\s+\S+/
         or next;
      push @regexps, qr/$pat/;
   }
}

{
   my $fn = $ARGV[1];
   open(my $fh, '<', $fn)
      or die "Cannot open data file \"$fn\": $!\n";

   while ( <$fh> ) {
      chomp;
      my $cnt = 0;
      for my $re (@regexps) {
         ++$cnt if /$re/;
      }
      print "$cnt $_\n";
   }
}
[download]

Other improvements:

• Added "use strict;", a tool that will help you find many errors.
• Since you weren't using the values of the %href, I got rid of it.
• Switched map for for since you discard the return value returned by map.
• Changed global variables FH and FD into lexicals.
• Used safer 3-arg open.

---

---

Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!

Titles consisting of a single word are discouraged, and in most cases are disallowed outright.

Read Where should I post X? if you're not absolutely sure you're posting in the right place.

Please read these before you post! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

Posts may use any of the Perl Monks Approved HTML tags:

a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr

You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)

	For:		Use:
	&		&
	<		&lt;
	>		&gt;
	[		&#91;
	]		&#93;

Link using PerlMonks shortcuts! What shortcuts can I use for linking?

See Writeup Formatting Tips and other pages linked from there for more info.