|Think about Loose Coupling|
I still don't get locking. I just want to increment the number in the file. How can I do this?by faq_monk (Initiate)
|on Oct 13, 1999 at 03:42 UTC||Need Help??|
Current Perl documentation can be found at perldoc.perl.org.
Here is our local, out-dated (pre-5.6) version:
Didn't anyone ever tell you web-page hit counters were useless? They don't count number of hits, they're a waste of time, and they serve only to stroke the writer's vanity. Better to pick a random number. It's more realistic.
Anyway, this is what you can do if you can't help yourself.
use Fcntl; sysopen(FH, "numfile", O_RDWR|O_CREAT) or die "can't open numfile: $!"; flock(FH, 2) or die "can't flock numfile: $!"; $num = <FH> || 0; seek(FH, 0, 0) or die "can't rewind numfile: $!"; truncate(FH, 0) or die "can't truncate numfile: $!"; (print FH $num+1, "\n") or die "can't write numfile: $!"; # DO NOT UNLOCK THIS UNTIL YOU CLOSE close FH or die "can't close numfile: $!";
Here's a much better web-page hit counter:
$hits = int( (time() - 850_000_000) / rand(1_000) );
If the count doesn't impress your friends, then the code might. :-)