How to solve set_time_limit not affecting PHP-CLI?

#!/usr/bin/php -q 
<?php
se开发者_如何学Pythont_time_limit(2);
sleep(5); // actually, exec() call that takes > 2 seconds
echo "it didn't work again";

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The max_execution_time limit, which is what set_time_limit sets, counts (at least, on Linux) the time that is spent by the PHP process, while working.

Quoting the manual's page of set_time_limit() :

Note: 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.
This is not true on Windows where the measured time is real.

When, you are using sleep(), your PHP script is not working : it's just waiting... So the 5 seconds you are waiting are not being taken into account by the max_execution_time limit.

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The solution here is to use pcntl_fork(). I'm afraid it's POSIX only. PHP will need to be compiled with --enable-pcntl and not --disable-posix. Your code should look something like this:

<?php

function done($signo)
{
    // You can do any on-success clean-up here.
    die('Success!');
}

$pid = pcntl_fork();
if (-1 == $pid) {
    die('Failed! Unable to fork.');
} elseif ($pid > 0) {
    pcntl_signal(SIGALRM, 'done');
    sleep($timeout);
    posix_kill($pid, SIGKILL);
    // You can do any on-failure clean-up here.
    die('Failed! Process timed out and was killed.');
} else {
    // You can perform whatever time-limited operation you want here.
    exec($cmd);
    posix_kill(posix_getppid(), SIGALRM);
}

?>

Basically what this does is fork a new process which runs the else { ... } block. At the (successful) conclusion of that we send an alarm back to the parent process, which is running the elseif ($pid > 0) { ... } block. That block has a registered signal handler for the alarm signal (the done() callback) which terminates successfully. Until that is received, the parent process sleeps. When the timeout sleep() is complete, it sends a SIGKILL to the (presumably hung) child process.

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Could you try running your php via exec and use the "timeout" command? (http://packages.ubuntu.com/lucid/timeout)

usage: timeout [-signal] time command.

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I'm ssuming that the script hangs in a loop somewhoere. Why not simply do a $STARTUP_TIME=time() the the script start, and then keep checking in the loop if the script neeeds to exit?

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Very hackish, but since I use cli scripts a lot, I admit shamefully to having slapped up a similar hack in the past. 2 scripts needed.

Your first cron script (the one that hangs) logs its starttime and processid in a flat file -> the function getmypid will be your friend for this. A second script run from cron every (x) minutes checks the flatfile, kills whatever has passed the alloted execution time, clears the flatfile and even logs in another file if you want.

Good luck ;)

UPDATE:

Remembered this question and came back to post this. While rummaging through Sebastian Bergmann's github account I stumbled on php-invoker. In the words of the author:

Utility class for invoking PHP callables with a timeout.

Although the current answer is very good for linux based non portable use, if cross-platform solution is needed this solution should be windows compatible, for those poor souls running on windoze. Mr Bergmann being a PHP god, I totally vouch for the quality of the script.

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EDIT 1

I noticed this comment in PHP manual:

Please note that, under Linux, sleeping time is ignored, but under Windows, it counts as execution time.

As far as what I understand, sleep is implemented as a system call and therefore ignored by PHP as described in the manual.

EDIT 2

there is an exec() running instead of sleep() there. and some exec() stuff hangs indefinitely. i am also searching for killing it from within exec (on linux shell), like exec(kill_after15secs myscript.sh), but i can't seem to find that either

I now see the actual question. Assuming that you're working in a Lunix/Unix environment, you can devise a solution around these lines:

<?php $pid = system( 'sh test.sh >test-out.txt 2>&1 & echo $!' ); ?>

Guess what, this captured the process id of the process you started. You can log it into a database or text file along with timestamp. In another cron script that runs, say, every 5 minutes, retrieve all process ids that were created 5 minutes ago and check if they are still running:

<?php $status = system( 'ps ' . $pid ); ?>

If process is still running, you get two lines of output:

 PID TTY STAT TIME COMMAND
2044 ?   S    0:29 sh test.sh

If so, terminate it like this:

<?php system( 'kill ' . $pid ); ?>

I wrote an article about creating background processes in PHP (and hunt them down afterwards). All examples were copied from there.

EDIT 3

All dots connected together:

<?php
    $pid = system( 'sh test.sh >test-out.txt 2>&1 & echo $!' );
    $timer = 300;
    while( --$timer ) {
        sleep(1);
        $status = system( 'ps ' . $pid );
        $status = explode( "\n", $status, 2 ); // I am not sure, please experiment a bit here
        if ( count( $status ) == 1 || trim( $status[ 1 ] ) == '' ) {
            die( 'spawned process ended successfully' );
        }
    }
    system( 'kill ' . $pid );
    die( 'spawned process was terminated' );
?>