-- Randal L. Schwartz, Perl hacker

Looking at the previous discussions on this, I've seen the code below. I was wondering if you were in a mod_perl enviroment, couldn't the same process call the function to generate the session twice in a second? I know with the random component that it's unlikely to have a collision but to be safe I've been using Timer::HiRes, is this overkill?

# How I've seen it suggested
use MD5;

sub generate_id {
    return substr(MD5->hexhash(time(). {}. rand(). $$. 'blah'), 0, 16)
+;
}

# Is this better or overkill?
use Time::HiRes qw(gettimeofday usleep);
use Digest::MD5 qw(md5_hex);

sub generate_sessionID {


    my ($s, $usec) = gettimeofday;    # Get time of day in seconds and
+ useconds

    usleep(1);    # Sleep for one usec so a persistant process can't c
+all it twice in a usec (for mod_perl)

    # Sessionkey is MD5 hash of seconds_since_epoch+usecs+process_id+r
+andom
    return substr(md5_hex($s.$usec.$$.rand()), 0, 32);
    

}
[download]



-Lee

"To be civilized is to deny one's nature."

My program is not in a mod_perl environment, so your solution might work for others but not for me.

mod_perl seems to require that I recompile Apache and I am frightened of doing it. In addition, I think that mod_perl is a Fool-Killer and breaks scripts that are written by fools like me who do not always do things the CGI.pm way.

Actually, it looks as though the semaphore solution offered by Japhy below will work and is within my capabilities to implement.