Question : file locking

Could someone give me a way of locking a file so it doesn't get messed up?  I need a file locking routine.

Answer : file locking

Assuming
1. You are using perl
2. Your server is unix, or another platform that supports flock
then the following code example is a simple perl package.

If your server is NT then I think that flock is not implemented and another technique will have to be used.
If you are testing on Personal Web Server then I think flock will give you a run-time error. The approach I use is to provide stub routines with 'flock' commented out when testing on PWS.

---- code example, Locking.pm ----
package Locking;
require Exporter;

@ISA = qw(Exporter);

#
# File locking routines
#
@EXPORT = qw();

#
# Obtain a file lock on a file
#
sub lock {
      my $fid = shift;
      
      flock($fid, 2);
}

#
# Release a file lock on a file
#
sub unlock {
      my $fid = shift;
      
      flock($fid, 8);
}
1;
---- end of example ----