To add up all the totals, simply declare a variable outside your loop and add each one.

my $total = 0;
while( my $line = <$FhIn> ) {                             
    my ($county, $year, $yr_tot) = split ' ', $line;      
      if ( $county == 26005 )  {                          
          print "$county  : $yr_tot\n";     
          $total += $yr_tot;                     
    }                                                         
}
[download]

 use strict;
 use warnings;

 my $total;

 while(<DATA>) {
    my ($county, $year, $yr_tot) = split;
    $total += $yr_tot if $county =~ /26005/;
 }
 print "Total for county 26005: $total\n";

__END__
26005 2004 1
26005 2004 2
26005 2004 3
26004 2004 1
26003 2004 1
[download]

The question isn't entirely clear ... but here's my inferrence.

First, use "==" rather than "eq" when comparing numbers. Of course, you may actually be comparing strings - but then put the string in quotes. For example, if "26005.0000" is the same as "26005", then use ==. If they're different, use eq, but put "26005" in quotes (single or double, doesn't matter).

(also, please don't put all those spaces at the end of the lines .. they're just distracting ;->)

use strict;
use warnings;

my $file = 'scott.d3';
my $FhIn;

open $FhIn, '<', $file or die "Could not open $file: $!";

my $total;
while( my $line = <$FhIn> ) {
   my ($county, $year, $yr_tot) = split ' ', $line;
   if ( $county == 26005 )  {
#  - or -
#  if ( $county eq '26005' )  {
     print "$county  : $yr_tot\n";
     $total += $yr_tot;
   }                                                         
}
close $FhIn or die $!;
print "Total yr_tot's: $total\n";
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use strict;                                              
use warnings;                                            
                                                         
my $file = 'scott.d3';                                    
my $FhIn;                 
my $all_yr_tot = 0;                               
                                                         
open $FhIn, '<', $file or die "Could not open $file: $!";
                                                         
while( my $line = <$FhIn> ) {                            
    my ($county, $year, $yr_tot) = split ' ', $line;      
      if ( $county eq 26005 )  {                          
   print "$county  : $yr_tot\n";
   $all_yr_tot += $yr_tot;                          
}                                                        
}                                                        
close $FhIn or die $!;
[download]

Hi! is there a regular expression I can use instead of my line of code 'if ( $county eq 26005 )' ?

1. Chances are you may want if ( $county == 26005 ) instead.
2. To answer your question: yes! But unless you have a very good reason to do so... don't!!

Also, for lines that match '$county eq 26005' I need to count/total the corresponding '$yr_tot' field on the same line. How do you total a $scalar column in perl? there doesn't appear to be a function similar to sql's 'count'.

To answer your question: $total+=$yr_tot.