php exec command (or similar) to not wait for result

I have a command I want to run, but I do not want PHP to sit and wait for the result.

<?php
echo "Starting Script";
exec('run_baby_run');
echo "Thanks, Script is running in background";
?>

Is it possible to have PHP not wait for the result.. i.e. just kick it off and move along to the next command.

I cant find anything, and not sure its even possible. The best I could find was someone making a CRON job to start in a minute.

Solution 1:

From the documentation:

In order to execute a command and have it not hang your PHP script while
it runs, the program you run must not output back to PHP. To do this,
redirect both stdout and stderr to /dev/null, then background it.

> /dev/null 2>&1 &

In order to execute a command and have
it spawned off as another process that
is not dependent on the Apache thread
to keep running (will not die if
somebody cancels the page) run this:

exec('bash -c "exec nohup setsid your_command > /dev/null 2>&1 &"');

Solution 2:

You can run the command in the background by adding a & at the end of it as:

exec('run_baby_run &');

But doing this alone will hang your script because:

If a program is started with exec function, in order for it to continue running in the background, the output of the program must be redirected to a file or another output stream. Failing to do so will cause PHP to hang until the execution of the program ends.

So you can redirect the stdout of the command to a file, if you want to see it later or to /dev/null if you want to discard it as:

exec('run_baby_run > /dev/null &');

Solution 3:

This uses wget to notify a URL of something without waiting.

$command = 'wget -qO- http://test.com/data=data';
exec('nohup ' . $command . ' >> /dev/null 2>&1 & echo $!', $pid);

This uses ls to update a log without waiting.

$command = 'ls -la > content.log';
exec('nohup ' . $command . ' >> /dev/null 2>&1 & echo $!', $pid);

Solution 4:

I know this question has been answered but the answers i found here didn't work for my scenario ( or for Windows ).

I am using windows 10 laptop with PHP 7.2 in Xampp v3.2.4.

$command = 'php Cron.php send_email "'. $id .'"';
if ( substr(php_uname(), 0, 7) == "Windows" )
{
    //windows
    pclose(popen("start /B " . $command . " 1> temp/update_log 2>&1 &", "r"));
}
else
{
    //linux
    shell_exec( $command . " > /dev/null 2>&1 &" );
}

This worked perfectly for me.

I hope it will help someone with windows. Cheers.

Solution 5:

There are two possible ways to implement it. The easiest way is direct result to dev/null

exec("run_baby_run > /dev/null 2>&1 &");

But in case you have any other operations to be performed you may consider ignore_user_abort In this case the script will be running even after you close connection.