php - It is correct to access same file from two different programs? -


so here goes, developing game can controlled via wi-fi, planning on modifying file via php webserver, file later read python program in constant loop detecting updates. @ given moment both python program , webserver open same file, there goes question...

this python code use:

file = open('file.ext', 'r') answer = file.readline() file.close()

and php code:

$dir = $_post['dir']; $file = fopen('file.ext', 'w+');  switch ($dir) {      case 'up':          fwrite($archivo, 'up');          break;     case 'down':          fwrite($archivo, 'down');          break;     case 'left':          fwrite($archivo, 'left');          break;     case 'right':          fwrite($archivo, 'right');          break;   } fclose($file);

thanks!


avoid accessing file @ same time in 2 programs. because problems might occure. think in same time read , write.

kind of problems known "mutual exclusion" means resources (for example: file) must in access 1 program (or process).
so can use known solutions of mutual exclusion "semaphore" or "lock". see below links more information:

php mutual exclusion (mutex) php mutual exclusion on file / mysql reading , executing statements file using perl mutual exclusion thread locking, dropping of queued functions upon mutex/lock release, in python? http://wiki.bash-hackers.org/howto/mutex


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