Edit report at https://bugs.php.net/bug.php?id=24797&edit=1
ID: 24797
Comment by: lucb1e at hotmail dot com
Reported by: spagmoid at yahoo dot com
Summary: feature request: way to close connection with
client?
Status: Bogus
Type: Feature/Change Request
Package: Feature/Change Request
Operating System: WinXP
PHP Version: 4.3.2
Block user comment: N
Private report: N
New Comment:
I would like to see this feature too, currently you'd need a very cumbersome way to do this (as
far as I know at least). This example is about an uploading script, which also synchronises with
other servers immediately (so no cronjob which would otherwise do the job).
The user opens the uploading page, and gets an upload form together with an invisible iframe. This
iframe is a php script that opens a listening socket and saves in a database table which port it is
on (together with the client's IP or, if available, session ID). This iframe-script also sets
ignore_user_abort.
When the user uploads a file, the processing script will do the following:
- Put the file somewhere and generate a download link;
- Echo the downloadlink to the user;
- ob_flush in the hope that the browser is smart enough to display the page already;
- Lookup the listening socket for this client in the database;
- Put the filename through to the iframe-script-which-has-listening-socket;
- die().
The 'iframe-script' then knows where the file is located which was just uploaded, and
without the user waiting for it, it can synchronise it with other servers - or do whatever it would
like to do.
This technique would theoratically work allright, but has a number of problems:
- Many webhosts do not support sockets at all;
- Listening sockets have even worse support as normal (client) sockets;
- Not all hosts allow you to set a custom maximum_execution_time, which is needed to prevent the
iframe-script from killing itself;
- I don't expect all hosts to support ignore_user_abort, though I didn't look into that
yet;
- It is unnessesarily complex compared to how easy it could be done with a kill_client_connection()
function.
Previous Comments:
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[2004-06-07 15:18:13] john_ramsden at sagitta-ps dot com
> Closing the connection itself from PHP is of course
> impossible, but if the remote client decides to close
> the connection then you can allow PHP to continue
> executing.
I have the same requirement as Spagmoid's, albeit for a different reason:
In my case it's a PHP script called by an SQL trigger - The script has to read the updated
records (to replicate them in another database); but the updated records aren't available until
the trigger completes, and the trigger can't complete until the PHP script disconnects! DUH!
Like Spagmoid's, my script obviously wouldn't try to send data after the disconnect, as
this doesn't make sense.
I must say, the PHP developers seem a bit dogmatic about this issue. Why should closing the
connection from PHP be "of course impossible"? What is to stop PHP having some interface
to tell Apache to do that without terminating the script itself?
I realize there's a simple workaround: the script can spawn an autonomous background process to
do "post processing". But I'm not aware of a portable PHP call to do this; so for a
platform-independent app, it would be lot cleaner if "early disconnects", followed by
post-processing, could be done in a single PHP script.
------------------------------------------------------------------------
[2004-03-25 14:18:50] php at digdug dot cx
I am looking for the same feature.
Here is the scenario: A user submits a form into script.php. The script needs to do two things:
1) Tell the user that the submission has been accepted. (It always is.)
2) Do some background processing on the submission and flag it if necessary. This takes up to half a
minute, so I don't want to make the user wait for it to finish.
So here is what I am trying to do:
<? insert_submission_into_database($submission); ?>
<html><body>
<? echo("submission accepted"); ?>
</html></body>
<?
close_connection_to_browser(); // currently not possible
if (submission_bad()) flag_submission();
// no further info is sent to the browser
?>
------------------------------------------------------------------------
[2003-07-26 19:24:35] rasmus@php.net
Sara already answered your request by pointing you at the connection handling chapter in the manual.
You are asking for a way to keep executing your script after the connection has been closed.
Closing the connection itself from PHP is of course impossible, but if the remote client decides to
close the connection then you can allow PHP to continue executing.
Please stop re-opening this.
------------------------------------------------------------------------
[2003-07-26 18:42:42] spagmoid at yahoo dot com
I DO NOT WANT TO SEND DATA TO THE CLIENT AFTER THE CONNECTION IS CLOSED. NOWHERE DID I SAY THAT.
That is what you people keep trying to tell me to do. I don't want to do that. I never wanted
to do that. I will never want to do that. That is ridiculous.
"The only time PHP can continue executing after the data stream has closed is when the browser
closes the connection itself."
I would be more inclined to believe this if you had understood any of the question.
"The only signal PHP can send to the webserver is "I'm done executing." It sends
this "signal" by terminating."
There may be another way to send this signal, but I doubt if either of you are in a position to tell
me.
"explaining your question in detail and making an attempt at civility by not attacking those
who take the time to respond."
It was in detail. "A way to close the connection with the client, while keeping the script
running?" That's it, period. It's not a complicated issue.
Sending a form letter that doesn't even match the question is not "taking the time to
respond".
------------------------------------------------------------------------
[2003-07-26 18:35:39] pollita@php.net
Again, through what mechanism do you intend to send data to the client *after* the connection is
closed?
But to address your original question. There is no way PHP can possibly close the data stream
between itself and the client since this stream is handled by the webserver.
The only signal PHP can send to the webserver is "I'm done executing." It sends this
"signal" by terminating. At this point your script can not continue executing because,
obviously, it has stopped.
The only time PHP can continue executing after the data stream has closed is when the browser closes
the connection itself.
Now, that said, might I suggest you attempt to ilicit a more courteous response in the future by
explaining your question in detail and making an attempt at civility by not attacking those who take
the time to respond.
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