Is there a way to use shell_exec without waiting for the command to complete?
PhpShellPhp Problem Overview
I have a process intensive task that I would like to run in the background.
The user clicks on a page, the PHP script runs, and finally, based on some conditions, if required, then it has to run a shell script, E.G.:
shell_exec('php measurePerformance.php 47 844 [email protected]');
Currently I use shell_exec, but this requires the script to wait for an output. Is there any way to execute the command I want without waiting for it to complete?
Php Solutions
Solution 1 - Php
How about adding.
"> /dev/null 2>/dev/null &"
shell_exec('php measurePerformance.php 47 844 [email protected] > /dev/null 2>/dev/null &');
Note this also gets rid of the stdio and stderr.
Solution 2 - Php
This will execute a command and disconnect from the running process. Of course, it can be any command you want. But for a test, you can create a php file with a sleep(20) command it.
exec("nohup /usr/bin/php -f sleep.php > /dev/null 2>&1 &");
Solution 3 - Php
You can also give your output back to the client instantly and continue processing your PHP code afterwards.
This is the method I am using for long-waiting Ajax calls which would not have any effect on client side:
ob_end_clean();
ignore_user_abort();
ob_start();
header("Connection: close");
echo json_encode($out);
header("Content-Length: " . ob_get_length());
ob_end_flush();
flush();
// execute your command here. client will not wait for response, it already has one above.
You can find the detailed explanation here: http://oytun.co/response-now-process-later
Solution 4 - Php
On Windows 2003, to call another script without waiting, I used this:
$commandString = "start /b c:\\php\\php.EXE C:\\Inetpub\\wwwroot\\mysite.com\\phpforktest.php --passmsg=$testmsg";
pclose(popen($commandString, 'r'));
This only works AFTER giving changing permissions on cmd.exe - add Read and Execute for IUSR_YOURMACHINE (I also set write to Deny).
Solution 5 - Php
Use PHP's popen command, e.g.:
pclose(popen("start c:\wamp\bin\php.exe c:\wamp\www\script.php","r"));
This will create a child process and the script will excute in the background without waiting for output.
Solution 6 - Php
Sure, for windows you can use:
$WshShell = new COM("WScript.Shell");
$oExec = $WshShell->Run("C:/path/to/php-win.exe -f C:/path/to/script.php", 0, false);
Note:
If you get a COM error, add the extension to your php.ini and restart apache:
[COM_DOT_NET]
extension=php_com_dotnet.dll
Solution 7 - Php
If it's off of a web page, I recommend generating a signal of some kind (dropping a file in a directory, perhaps) and having a cron job pick up the work that needs to be done. Otherwise, we're likely to get into the territory of using pcntl_fork() and exec() from inside an Apache process, and that's just bad mojo.
Solution 8 - Php
That will work but you will have to be careful not to overload your server because it will create a new process every time you call this function which will run in background. If only one concurrent call at the same time then this workaround will do the job.
If not then I would advice to run a message queue like for instance beanstalkd/gearman/amazon sqs.