note 59884 added to function.system

The documentation notes that for making a program running in the background: ... you have to make sure that the output of that program is redirected to a file or some other output stream ... But simply redirecting the command's output to a fifo will also cause PHP to wait for the command to terminate, even if it is started in background. After quite a bit of trial & error, however I figured out that the trick (mentioned in some other note) using parenthesis to regain control over an already redirected STDOUT does work here, too: <? // this will not execute the echo in background while continuing the PHP-script, // as one might expect system("echo 'something' >$someFIFO &"); // however that will do the trick - the echo is run in background, waiting until the data is read // from the FIFO, while your PHP-script continues execution, e.g. being able to open that // FIFO for read without being blocked until some data will arrive!! system("(echo 'something' >$someFIFO) >/dev/null &"); ?> ---- Manual Page -- http://www.php.net/manual/en/function.system.php Edit -- http://master.php.net/manage/user-notes.php?action=edit+59884 Delete: added to the manual -- http://master.php.net/manage/user-notes.php?action=delete+59884&report=yes&reason=added+to+the+manual Delete: bad code -- http://master.php.net/manage/user-notes.php?action=delete+59884&report=yes&reason=bad+code Delete: spam -- http://master.php.net/manage/user-notes.php?action=delete+59884&report=yes&reason=spam Delete: useless -- http://master.php.net/manage/user-notes.php?action=delete+59884&report=yes&reason=useless Delete: non-english -- http://master.php.net/manage/user-notes.php?action=delete+59884&report=yes&reason=non-english Delete: already in docs -- http://master.php.net/manage/user-notes.php?action=delete+59884&report=yes&reason=already+in+docs Delete: other reasons -- http://master.php.net/manage/user-notes.php?action=delete+59884&report=yes Reject -- http://master.php.net/manage/user-notes.php?action=reject+59884&report=yes Search -- http://master.php.net/manage/user-notes.php