How to execute shell command from php in background

Question

How can I execute shell command in background using & at the end? I've try:

php -r "shell_exec('sleep 10 &');"

and

php -r "shell_exec('/bin/bash -c \"sleep 10 &\"');"

in both cases it pause for 10 seconds instead of just give the shell back and run sleep in background.

Answer 1

You have to reroute the output somewhere. Try something like this:

php -r "shell_exec('sleep 10 > /dev/null &');"