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set_time_limit

(PHP 3, PHP 4, PHP 5)

set_time_limit -- Limits the maximum execution time

Description

void set_time_limit ( int seconds )

Set the number of seconds a script is allowed to run. If this is reached, the script returns a fatal error. The default limit is 30 seconds or, if it exists, the max_execution_time value defined in the php.ini. If seconds is set to zero, no time limit is imposed.

When called, set_time_limit() restarts the timeout counter from zero. In other words, if the timeout is the default 30 seconds, and 25 seconds into script execution a call such as set_time_limit(20) is made, the script will run for a total of 45 seconds before timing out.

警告

set_time_limit() has no effect when PHP is running in 安全模式. There is no workaround other than turning off safe mode or changing the time limit in the php.ini.

注: The set_time_limit() function and the configuration directive max_execution_time only affect the execution time of the script itself. Any time spent on activity that happens outside the execution of the script such as system calls using system(), stream operations, database queries, etc. is not included when determining the maximum time that the script has been running.

See also: max_execution_time and max_input_time ini directives.


add a note add a note User Contributed Notes
28-Sep-2006 05:03
After the error

Fatal error: Maximum execution time of [...] seconds exceeded [...]

has appeared, shut-down functions are still called (afterwards). So, by using register_shutdown_function, you can save data in a session and offer the user a link to start the script again. Then the script can go on with the Session-data.

Example: if you are analyzing a text-file, you can save your analyzed data in a session together with the position of the filepointer (ftell) and start from that possition the next time the user runs the script (fseek).

To determine whether the script was finished or aborted, you simply set a bool false at the beginning and true at the end, and in the shutdown-function you check if it's still false.
konrads dot smelkovs at gmail dot com
01-Apr-2006 10:35
If you are streaming large data from database, it is counted towards the max exec time.
jatin at jatinchimote dot com
02-Mar-2006 02:54
If you set the number of seconds to a very large number (not many ppl do that, but just in case) then php exits with a fatal error like :

Fatal error: Maximum execution time of 1 second exceeded in /path/to/your/script/why.php
Cleverduck
01-Mar-2006 05:36
Regarding what 'nytshadow' said, it's important to realize that max-execution-time and the set_time_limit functions measure the time that the CPU is working on the script.  If the script blocks, IE: for input, select, sleep, etc., then the time between blocking and returning is NOT measured.  This is the same when running scripts from the command line interface.  So if you've got a log parser written in PHP that tails a file, that program WILL fail eventually.  It just depends how long it takes to read in enough input to process for 30 seconds.

If you're writing a command line script that should run infinitely, setting max-execution-time to 0 (never stop) is HIGHLY recommended.
rycardo74 at gmail dot com
25-Nov-2005 02:52
this work to fine html streaming AND time pass limit

<?
header('Content-type: text/plain');
echo date("H:m:s"), "\n";
set_time_limit(30);
for ($i = 0; $i < 1000; $i++)
{

   echo date("H:m:s"),"\n";
   for ($r = 0; $r < 100000; $r++){
   $X.=  tan(M_LNPI+log(ceil(  date("s")*M_PI*M_LNPI+100)));
   }
   ob_flush(); 
   flush();

}
echo "work! $x";
?>
Balin 4 ever
G8 = lies
free your mind
nytshadow
14-Jul-2005 11:15
This tripped me up for a bit until I read through the ini settings.  When doing file uploads, max_execution_time does not affect the time even though the error message indicates the script has exceeded the maximum execution time.  The max_input_time determines how much time PHP will wait to receive file data.  The default setting is 60 seconds so while I had my max_execution_time set to 300, the script would fail after 60 seconds but report that it had exceeded the max execution time of 300.
niam dot niam at gmail dot com chebatron at gmail dot com
24-Jun-2005 09:43
<?php
echo date("H:m:s"), "\n";
set_time_limit(30);
for ($i = 0; $i < 100; $i++)
{
   sleep(10);
   echo date("H:m:s"),"\n";
}
echo "Done!";
?>

Guys! This script runs 100*10 seconds +- few microseconds for circle and output.
But not promissed 30 seconds!!!
set_time_limit sets CPU time! Texted on *NIX.
Sjoerd van der Hoorn
21-Jun-2005 06:08
When using the set_time_limit() function, the browser will stop after about 30 seconds if it does not get new data. To prevent this, you can send every 10 seconds a little snippet of data (like a single character) to the browser. The code below is tested with both Internet Explorer and Firefox, so it will stay online all the time.

You should also create a file called chatdata.txt which contains the last thing said on a chatbox. Please note that you can also replace this function with a MySQL or other database function...

<?php

set_time_limit(900);

// Start output buffering
ob_start();

$message = "First test message";
$oldmessage = "bla";

// Keep on repeating this to prevent PHP from stopping the script
while (true)
{
   $timeoutcounter = 0;
   while ($message == $oldmessage)
   {
       // If 10 seconds elapsed, send a dot (or any other character)
       if ($timeoutcounter == 10)
       {
           echo ".";
           flush();
           ob_flush();
           $timeoutcounter = 0;
       }
       // Timeout executing
       sleep(1);
       // Check for a new message
       $message = file_get_contents("chatdata.txt");
       $timeoutcounter++;
   }

   // Keep the old message in mind
   $oldmessage = $message;

   // And send the message to the user
   echo "<script>window.alert(\"" . $message . "\");</script>";

   // Now, clear the output buffer
   flush();
   ob_flush();
}

?>
eric pecoraro at shepard com
06-Jun-2005 03:57
I was having trouble with script timeouts in applications where the user prompted long running background actions. I wrote this cURL/CLI background script that solved the problem when making requests from HTTP.

<?php

/* BACKGROUND CLI 1.0
  
   eric pecoraro _at_ shepard dot com - 2005-06-02
   Use at your own risk. No warranties expressed or implied.

   Include this file at the top of any script to run it in the background
   with no time limitations ... e.g., include('background_cli.php');
  
   The script that calls this file should not return output to the browser.
*/
#  REQUIREMENTS - cURL and CLI
   if ( !function_exists('curl_setopt') OR !function_exists('curl_setopt')  ) {
     echo 'Requires cURL and CLI installations.' ; exit ;
   }
  
#  BUILD PATHS
   $script = array_pop(explode('/',$SCRIPT_NAME)) ;
   $script_dir = substr($SCRIPT_NAME,0,strlen($SCRIPT_NAME)-strlen($script)) ;
   $scriptURL = 'http://'. $HTTP_HOST . $script_dir . "$script" ;
   $curlURL = 'http://'. $HTTP_HOST . $script_dir . "$script?runscript=curl" ;

#  Indicate that script is being called by CLI
   if ( php_sapi_name() == 'cli' ) {
     $CLI = true ;
   }

#  Action if script is being called by cURL_prompt()
   if ( $runscript == 'curl' ) {
     $cmd = "/usr/local/bin/php ".$PATH_TRANSLATED ; // server location of script to run
     exec($cmd) ;
     exit;
   }

#  USER INTERFACE
   // User answer after submission.
   if ( $post ) {
     cURL_prompt($curlURL) ;
     echo '<div style="margin:25px;"><title>Background CLI</title>';
     echo 'O.K. If all goes well, <b>'.$script.'</b> is working hard in the background with no ' ;
     echo 'timeout limitations. <br><br><form action='.$scriptURL.' method=GET>' ;
     echo '<input type=submit value=" RESET BACKGROUND CLI "></form></div>' ;
     exit ;
   }
   // Start screen.
   if ( !$CLI AND !$runscript ) {
     echo '<title>Background CLI</title><div style="margin:25px;">' ;
     echo '<form action='.$scriptURL.' method=POST>' ;
     echo 'Click to run <b>'.$script.'</b> from the PHP CLI command line, in the background.<br><br>' ;
     echo '<input type=hidden value=1 name=post>' ;
     echo '<input type=submit value=" RUN IN BACKGROUND "></form></div>' ;
     exit ;
   }

#  cURL URL PROMPT FUNCTION
   function cURL_prompt($url_path) {
     ob_start(); // start output buffer
     $c=curl_init($url_path);
     curl_setopt($c, CURLOPT_TIMEOUT, 2); // drop connection after 2 seconds
     curl_exec($c);
     curl_close($c);
     ob_end_clean(); // discard output buffer
   }
?>
Jimmy Wimenta
24-Sep-2004 03:15
Referring the the last 2 comments about whether the duration of sleep() will be counted in execution time, the answer is it depends on the platform. In Linux it does not, while in Windows it does.
nathan
06-Apr-2004 05:04
unless I am doing something stupid, my testing (at least on php 4.3.4) seems to indicate that sleep() does indeed count towards script execution time, contrary to the previous post.

Here is my test code:

for ($i=0; $i < 10; $i++) {
   sleep(10);
   echo " [$i] ";
}

This will exceed execution time after only 2 loops.
riki1512 at gmx dot de
02-Apr-2004 08:26
The duration of the pause when calling the sleep() function is also not added to script-execution time.
php at mightycpa.com
27-Jun-2003 04:30
You may also need to look at Apache's timeout setting (Win32 version for me), I changed max execution time value in php.ini, and still got stopped by Apache's timeout value in the httpd.conf file.
rsallo at gna dot NOSPAM dot es
30-May-2003 07:28
When you are working with IIS, PHP timeout is valid only when it's lower than script timeout defined by IIS.

IIS 5 has a default timeout of 300 seconds. If you need a higher timeout, you also have to change IIS properties. Otherwise, your server will stop your PHP script before it reaches its own timeout.
16-Oct-2001 08:04
user abort stop the script
see "ignore_user_abort"
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