If you need to start process in background and get its PID to manage it later using PHP.
<?php function runInBackground($command,$log,$priority=0) { if($priority) $PID=shell_exec("nohup nice -n $priority $command > $log 2>&1 & echo $!"); else $PID=shell_exec("nohup $command > $log 2>&1 & echo $!"); return($PID); } ?>
echo $! will return process ID
# Command & echo $!
Check if process is running
<?php function isProcessRunning($PID) { if($PID==0)return false; if($PID=="")return false; exec("ps -p $PID 2>&1",$state); return(count($state)>=2); } ?>
Display Process Logs
<?php function displayProcessLog($logfile) { exec('cat $logfile 2>&1',$log); return implode("\r\n",$log); } ?>
Kill Process
<?php function killProcess($PID) { exec('kill '.$PID.' 2>&1',$status); return implode("\r\n",$status); } ?>
Save Process ID to file
#!/bin/bash
Command &
echo $! >/path/to/pid.file
