如何设置进程以便在另一个进程之后执行？

Question

I have a php video uploader script and at the end it initiates an ffmpeg script for the conversion of the uploaded file. It then inserts the video info into a mysql database and in the status field, a value of 0 since the file is being processed.

I was thinking that along with the linux ffmpeg command I could put a delayed process that executes a php file so that after the file is converted and the ffmpeg process is complete it executes the php file and that file has an update statement and can update the video entry in the mysql database under status to 1. To do that though I need to somehow pass the video id into the terminal so it can pass it to the php file...Anyone know how to do this?

$sql = 'INSERT INTO video (id, uploader, video_id, status) VALUES(?,?,?,?)';
$stmt3 =$conn->prepare($sql);
$result=$stmt3->execute(array($id,$username,$video_id,0));

$command = shell_exec('/usr/local/bin/ffmpeg -i /home/g/Desktop/'.$id2.' -acodec libfaac -aq 100 -vcodec libx264 -preset slow -crf 22 -threads 0 /home/g/Desktop/'.$id2.'.flv');

Answer 1

Try this:

$command = shell_exec('/usr/local/bin/ffmpeg -i /home/g/Desktop/'.$id2.'' .
    '-acodec libfaac -aq 100 -vcodec libx264 -preset slow -crf 22 -threads 0' .
    '/home/g/Desktop/'.$id2.'.flv && /usr/bin/php /home/g/bin/update_db.php ' . $id2);

It says to execute '/usr/bin/php /home/g/bin/update_db.php ' . $id2 if the ffmpeg(1) command succeeds. (It might fail.)

To try this at the shell: true && echo hi and false && echo hi.