#34589 [Bgs->Csd]: Strange effects of file_exists() etc. caching

ID: 34589 User updated by: pjf at asn dot pl Reported By: pjf at asn dot pl -Status: Bogus +Status: Closed Bug Type: *Directory/Filesystem functions Operating System: GNU PHP Version: 5.0.5 New Comment: To "outsmart the cache"... Rest in piece, Unix principles. Hint for those who encounter the same problem as mine: use realpath(). A hack, but works as file_exists() should. Previous Comments: ------------------------------------------------------------------------ [2005-09-21 22:33:50] tony2001@php.net No, I don't think so. If you're trying to outsmart the cache jumping from/into different directories and doing the stat() using *relative* path - this is not PHP problem (and it can be easily solved with clearstatcache(), but I've already told you that). ------------------------------------------------------------------------ [2005-09-21 22:21:44] pjf at asn dot pl Don't you think that the key that is used to access the cache should be the _full_, _absolute_ path instead of just the string passed to file_exists()? Current solution doesn't guarantee proper results - how do you know whether the code you call doesn't change into some other directory and stats() eg. "foo" won't interfere with the other piece code checking for "foo" existence in other directory? The only way to do such checks reliably is to call clearstatcache() _each_ _time_ what makes the cache useless. At least for me. I think it's a design error. ------------------------------------------------------------------------ [2005-09-21 22:02:02] tony2001@php.net Thank you for taking the time to write to us, but this is not a bug. Please double-check the documentation available at http://www.php.net/manual/ and the instructions on how to report a bug at http://bugs.php.net/how-to-report.php Use clearstatcache() to clear the cache. ------------------------------------------------------------------------ [2005-09-21 21:55:45] pjf at asn dot pl I made mistake in the code - here is the corrected version: touch("foobar"); echo file_exists("foobar") . "\n"; mkdir("foodir"); chdir("foodir"); echo file_exists("foobar") . "\n"; ------------------------------------------------------------------------ [2005-09-21 21:51:41] pjf at asn dot pl Description: ------------ I find caching of file_exists() and similar functions causing strange results - as presented by attached code, it might cause unexistent files to... "exist" :). Reproduce code: --------------- [pjf@boogoo file_exists]$ ls file_exists.php [pjf@boogoo file_exists]$ cat file_exists.php <?php touch("foobar"); echo file_exists("foobar") . "\n"; mkdir("foodir"); echo file_exists("foobar") . "\n"; ?> Expected result: ---------------- [pjf@boogoo file_exists]$ php file_exists.php 1 Actual result: -------------- [pjf@boogoo file_exists]$ php file_exists.php 1 1 ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=34589&edit=1