I had a similar situation where I had a fixed length file generated on a mainframe. I actually used this to do some edits and inserted rows into an Oracle database, but I've shortened it a bit here and used joining the record with a "pipe":

#!/usr/bin/perl
use strict;

my @record_layout = qw(
   state_code
   place_code
   state_alpha_code
   class_code
   place_name
   county_code
   county_name
   zip_code
);

my %field_types = (
   state_code        => 'A2',
   place_code        => 'A5',
   state_alpha_code  => 'A2',
   class_code        => 'A2',
   place_name        => 'A52',
   county_code       => 'A3',
   county_name       => 'A22',
   zip_code          => 'A5'
);
my %fips_data;

my $fips_template = join(" ", @field_types{@record_layout});

while(my $fips_line = <>){
   @fips_data{@record_layout} = unpack($fips_template, $fips_line);
   next if $fips_data{'state_code'} == 52;
   print STDOUT join('|', @fips_data{@record_layout});
}
[download]

Update: This post and its follow-up keep getting panned. It would be nice to get some constructive criticism rather than watching the numbers continue to fall on this, after all I would like to know what's wrong or could be done better so I can grow as a Perl programmer.

Thanks,
Mike

"The two most common elements in the universe are hydrogen... and stupidity."
Harlan Ellison