Shelling without waiting

In a php script I am using I need to call an external program and have
it start running, but I don't want the php script to wait for it to
finish. Looking at exec() and system() these would all seem to wait
for the external program to complete before they came back. Is there a
way of doing this without waiting for the results?

The program I want to run is a perl script that takes data stored by
the php program and then creates pdf's and preview images of these.
Instead of the php (and user) waiting the 15 seconds or more for this
to happen, I want to call this external program and then let the user
(via flash and php) poll the server to see if it is done. When I was
doing this in perl alone I was able to flush out the results of the
flash post back to flash and then the perl could just grind along till
it was done, is this a possible scenario in php (though I would prefer
the 1st scenerio of starting the external program and leaving)?

Any ideas, weblinks, documentation is appreciated

Bill H

On Fri, 05 Sep 2008 04:28:16 -0700, Bill H wrote:May you can do a fork() before doing an exec().

On 5 Sep, 12:28, Bill H <b...@ts1000.uswrote:<?php
$started=`at now script.pl $arg`;
?>

C.

On 5 Sep, 13:46, "C. (http://symcbean.blogspot.com/)"
<colin.mckin...@gmail.comwrote:That is the equivalent of shell_exec and it will still await the
completion of the command.

On Sep 5, 8:21*am, Sjoerd <sjoer...@gmail.comwrote:I thought of this Sjoerd, but it doesn't seem to be what I am looking
for. A solution I thought of, but it isn't elegant, is to shell_exec()
an intemediatary perl program that would then start up the real script
in the background. The intemediatary program would return immediately
to php once it started the other one. But this seems to be too much of
a kludge.

Bill H

Bill H wrote:resource popen ( string command, string mode )


Opens a pipe to a process executed by forking the command given by command.

On 5 Sep, 14:02, Captain Paralytic <paul_laut...@yahoo.comwrote:No it won't: read it again.

C.

On Sep 6, 12:40*pm, "C. (http://symcbean.blogspot.com/)"
<colin.mckin...@gmail.comwrote:shell_exec — Execute command via shell and return the complete output
as a string

How can the complete output be returned if it does not await the
completion of the command?

On 6 Sep, 12:48, Captain Paralytic <paul_laut...@yahoo.comwrote:man at

C.