Even i tried this code from the same book . Following is my code

#!/usr/bin/perl
use strict;
use Fcntl qw (LOCK_EX);
use Fcntl;
use DB_File;
use constant COUNT_FILE => "count.dbm";
my %count;
my $num_hits;
my $url = $ENV{REQUEST_URI};
local *DBM;

print "Content-type : text/plain\n\n";
my $db = tie %count , "DB_File" , COUNT_FILE , O_RDWR | O_CREAT;
if( $db ) {
    my $fd = $db->fd;
    open DBM , "+<&=$fd" or die "Count not dump DBM for lock: $!";
    flock DBM,LOCK_EX;
    undef $db;
    $count{$url} = 0 unless exists $count{$url};
    $num_hits = ++$count{$url};
    untie %count;
    close DBM;
    print "$num_hits\n";
}else{
        print "[Error processing counter data]\n";
}
[download]

Following are my observations

when run the code from my terminal it updates the count and prints

root@inll11325816l:/usr/lib/cgi-bin# perl counter.cgi Content-type : text/plain 11 root@inll11325816l:/usr/lib/cgi-bin# vi counter.cgi root@inll11325816l:/usr/lib/cgi-bin# perl counter.cgi Content-type : text/plain 12 root@inll11325816l:/usr/lib/cgi-bin# vi counter.cgi root@inll11325816l:/usr/lib/cgi-bin# perl counter.cgi Content-type : text/plain 13 root@inll11325816l:/usr/lib/cgi-bin# perl counter.cgi Content-type : text/plain 14

When i run from the Browser it just exits from the if loop and prints the statement in the else block I have another question also here , why there is no check for the URI we are accessing here , wht if the DOCUMENT_URI or REQUEST_URI ( in my case has a different .html file that is been accessed Can anyone please help here ?