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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 ( [id://806]=perlfaq nodetype: print w/replies, xml ) | 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. :-)
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