Perl read write file example, each time access it will plus one.

like.pl

#!/usr/local/bin/perl -w
use CGI qw(:standard);
use CGI::Carp qw(fatalsToBrowser set_message);
my $q = CGI->new;
my $filename = '/gsa/a23gsa/.projects/p1/aheweb23/projects/wwwstage/content/innovation/cn/like/db.txt';

my $like = 0;
print $q->header('text/plain');

# Read like count and plus one
open(my $fh, '<', $filename) or die "Can't open $filename: $!";
while (my $line = <$fh>) {
  $like = $line + 1;
}

# Write new like count
open(my $fh, '>', $filename);
print $fh $like;

close $fh;

# Read like count
open( my $fh, '<', $filename ) or die "Can't open $filename: $!";
while ( my $line = <$fh> ) {
    print $line;
}

close $fh;