To run a command in background, the output must be redirected to /dev/null. This is written in exec() manual page. There are cases where you need the output to be logged somewhere else though. Redirecting the output to a file like this didn't work for me:
<?php
shell_exec("my_script.sh 2>&1 >> /tmp/mylog &");
?>
Using the above command still hangs web browser request.
Seems like you have to add exactly "/dev/null" to the command line. For instance, this worked:
<?php
shell_exec("my_script.sh 2>/dev/null >/dev/null &");
?>
But I wanted the output, so I used this:
<?php
shell_exec("my_script.sh 2>&1 | tee -a /tmp/mylog 2>/dev/null >/dev/null &");
?>
Hope this helps someone.
