将php exec存储在会话变量中

Question

Is is possible to store an exec' output into a session variable while its running to see it's current progress?

example:

index.php

<?php exec ("very large command to execute", $arrat, $_SESSION['output']); ?>

follow.php

<php echo $_SESSION['output']); ?>

So, when i run index.php i could close the page and navigate to follow.php and follow the output of the command live everytime i refresh the page.

Answer 1

No, because exec waits for the spawned process to terminate before it returns. But it should be possible to do with proc_open because that function provides the outputs of the spawned process as streams and does not wait for it to terminate. So in broard terms you could do this:

1. Use proc_open to spawn a process and redirect its output to pipes.
2. Use stream_select inside some kind of loop to see if there is output to read; read it with the appropriate stream functions when there is.
3. Whenever output is read, call session_start, write it to a session variable and call session_write_close. This is the standard "session lock dance" that allows your script to update session data without holding a lock on them the whole time.