Well I'm not sure about squid, but you should break this into two parts:
in reply to Re^2: read an integer from a file
in thread read an integer from a file
You might not get as much help with part 2 from Perlmonks as you would like, but you will get more help with part 1 if you're clear about what's going wrong.
- check you are getting the behaviour you expect WITHOUT squid,
- integrate with squid.
Since you asked again in the chatterbox about "problem reading a file", I advise you again to look at IO::All. If you're lucky, you can install it just by typing "cpan IO::All". If it turns out to be a bit more complicated, it's definitely worth at least one whole week of effort to get cpan working properly. If you can't install modules from cpan, you are missing out on most of the power of Perl, and you may even find people here getting frustrated with you. The particulars of installing cpan modules vary from site to site, so if you have problems, it's a good idea to talk to other people using Perl at your location.