[forwarded submission from a non-member address -- rjk]
From: Uri Guttman <[EMAIL PROTECTED]> Date: Wed, 31 Oct 2001 15:07:14 -0500 Subject: Re: [Boston.pm] warmfuzzies while locking file To: [EMAIL PROTECTED] CC: [EMAIL PROTECTED], [EMAIL PROTECTED] >>>>> "JT" == John Tobey <[EMAIL PROTECTED]> writes: JT> If by "work" you mean do something useful, yes, this might "work". JT> However, it misses my point (that flock() returns a value that one JT> ought not ignore). It may fail and return undef if the filesystem JT> does not support locks, because of some resource shortage, or because JT> the Yankees won. It is really easy in Perl to check a return value JT> that you assume to be always true: add "or die". JT> I've used flock() in perhaps half a dozen Perl programs over my JT> career, and every time I reread perldoc -f flock. check out the perl cookbook for a portable and better lock that uses mkdir as an atomic lock. it has several advantages as it works over the net and it works over multiple platforms. i wrote my own version of it for a project a few years ago. one point, it creates a separate lock and doesn't lock a particular file. this is good when you want to lock a bunch of files at once. it does have one problem of cleaning up if your program doesn't exit nicely whereas flock will release no matter what when a program exits. this can be worked around too. uri -- Uri Guttman --------- [EMAIL PROTECTED] ---------- http://www.sysarch.com SYStems ARCHitecture and Stem Development ------ http://www.stemsystems.com Search or Offer Perl Jobs -------------------------- http://jobs.perl.org
