Hi,

I have a file which store a counter, whenever the CGI script is accessed, the counter in that file will be incremented. I have used flock() to ensure the file is locked before updating it, but sometimes it get resetted to 0 when the traffic is high. Did I write something wrong in my script? Or is it becuase of the file locking machanism? Is there any work around on this? I am using Redhat Linux 9, Apache 2.0 with perl 5.8.3

Does anyone of you encounter this problem before? Thanks!

The following are the counter code that I am using: 

#!/usr/local/bin/perl

use strict;

use CGI qw(:all);
my $file = 'counter.txt';

my $counter = 0;
{
  local *FH;
  open(FH, "+<$file") || die $!;
  flock(FH, 2) || die $!;
  
  $counter = <FH>;
  
  seek(FH, 0, 0);
  truncate(FH, 0);
        
  print FH $counter+1;
  close(FH);
}

print header();
print "counter[$counter]\n";

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Regards,
Perl Beginner

In reply to Concurrent file access with flock() by Anonymous Monk

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