Flock works on systems that matter. It works on Unix systems, and NT systems. It does not work on Win9x systems, and that doesn't count, as far as CGI applications are concerned.
Anyone hosting apps such as UBB on a Win9x box has bigger problems to worry about than flock.
Sometimes external locking routines are necessary, but they are not preferred due to race conditions. My personal feeling is that flock should always be used, and if that makes it incompatible on a win9x system, too bad.
It's easy enough to code it so that it won't generate an error under win9x, but it just means that win9x won't get locking. That also means that it shouldn't be used in production on a win9x system, but again, my feeling is that win9x systems shouldn't be used in the first place (for production)
--mark
