I'm trying to fork a command line run XAMPP php process using pcntl\_fork(). When I run the command below:

```
$pid = pcntl_fork();
if($pid == -1){
    file_put_contents('testlog.log',"\r\nFork Test",FILE_APPEND);
    return 1; //error
}
else if($pid){
    return 0; //success
}
else{   
    file_put_contents($log, 'Running...', FILE_APPEND);
}

```

I get:

```
Fatal error: Call to undefined function pcntl_fork()

```

Can anyone suggest how to fix this?