I am having a strange issue. I recently set up a process on our test servers to call a script asynchronously from another script. It has been working during testing, up until recently. Let me give some of the technical details before proceeding. The call from the originating script looks like this (I have updated the logic that makes the call):
exec('cmd /S /C "'.$command.' 1> nul 2>&1"');
Where $command is created using the following logic:
$args = array(
'php',
'"'.getcwd().'{absolute path to a php script}"',
escapeshellarg($job_id),
escapeshellarg($vhost),
escapeshellarg($debug),
);
$command = implode(' ', $args);
PHP version is 5.3.10 and the server is a hosted box running Windows Server 2008 R2 Standard.
I have verified that php is still in the system path
I have used debug output to see that the asynch call is being made, and what args it is being made with -everything still seems to be correct.
If I call the command contained in $command manually from the windows system terminal it runs as expected
If I run the $command as exec would run it (with 'cmd /S /C' it fails complaining that it cannot open the php script)
What really boggles my mind is that this was working this time last week. I made a few changes to the code (seemingly unrelated) and even after reverting my changes to see if that was the problem - this process is still broken.
At this point I am mystified and would welcome any insight, ideas or help.
Eventually I was able to simply get around this problem by not using popen or exec at all, it seems like those may be best avoided when using PHP on a Windows platform - if you are trying to create an asynchronous script call that is. Instead I resorted to the Windows COM object support in PHP.
$handle = new COM('WScript.Shell');
$handle->Run($command, 0, false);
This starts the process in the background (hides window/does not open a new window) and executes it asynchronously - i.e. does not wait for it to finish.
Included here is the documentation page for WScript.Shell which gives the official description of the effect(s) of the parameters passed. Although I did not stop to benchmark it, I will say that anecdotally it feels that his process now runs more quickly than it used to when I was trying to use exec/popen/etc.
Rather than redirecting the output to nul, try redirecting everything to a file. That should tells you if there's a PHP error somewhere:
$outFilePath = "/path/to/file.log";
pclose (popen('start /B cmd /S /C "'.$command.' > ' . $outFilePath . ' 2>' . $outFilePath . ' &"',"r") );
Also is there any reason you are using pclose / popen rather than something more simple like exec?
Related
I have a Windows Server 2016 VPS with Plesk and PHP 7.1x.
I am trying to execute a simple AutoHotKey script from PHP using the following command:
<?php shell_exec('start /B "C:\Program Files\AutoHotkey\AutoHotkey.exe" C:\inetpub\vhosts\mydomain.com\App_Data\myahkscript.ahk'); ?>
This is the only line on the page. I have tried different ahk scripts, the current one simply creates a MsgBox.
When I execute my php page, on VPS Task Manager I see three processes created with the expected USR: cmd.exe, conhost.exe and php-cgi.exe. However, my PHP page just sits waiting on the server and nothing actually happens on the server.
I have also tried the same line except replacing shell_exec with exec. This seems to make no difference. I have tried without start /b with both commands. In that case the PHP page completes but no new processes are started.
I cannot find any errors in any logs: Mod_Security, Plesk Firewall, IIS.
Any ideas?
EDIT:
I tried my command from the VPS command prompt and immediately slapped in the face with the obvious issue of the space in 'Program Files'. I quoted the string as shown above and the command works. This eliminated the hang when running from PHP. However, the command still does nothing when executed from the web page.
EDIT:
Based on suggestions from the referenced post 'debugging exec()':
var_dump: string(0)""
$output: Array()
$return_val: 1
One point was that I would probably not be able to invoke GUI applications. That puts a damper on the idea.
This question already has answers here:
How do you run a .bat file from PHP?
(7 answers)
php How do I start an external program running - Having trouble with system and exec
(3 answers)
Closed 3 years ago.
Before everyone starts butting in with "security risks" "cant be done" stop there and read the ENTIRE post
I have a web server set up from a home laptop which is serving as a games web server im trying to create a GUI so its easier for us to maintain the server and im trying to use batch files to do the actions on the computer
So to put this into perspective I have my index file index.php
<form method="post">
<input type="submit" name="startServer" value="Start Server">
</form>
<?
if(isset($_POST['startServer'])){
exec('batch/startServer.bat');
}
?>
And my startServer.bat will run on the laptop running the server and will do all the actions nesscary to start our game server so there is another directory "Instance" containing an excutable "Server.exe" which the batch file will run
The issue im having is running the web server and testing this it doesnt work if I open the batch file directly it works but it seems the php code doesnt work
For clarification I am using apache and my browser is chrome
And just a quick question for anyone willing to answer the route im going is correct right? Using php would allow everything to run on the machine hosting the server so the end user will only see the GUI and the server would run the batch files and everything on the web server and not the local machine if that makes sense?
EDIT: To be more clear about what's going on the function exec runs but it just hangs like the application is loading I need a solution that will actually open the application are my host computer for example if I wanted to open up notepad I press a button on the Web server and notepad will open on the computer
EDIT 2: I would like to note that I dont exactly need to use the exec function and I have tried all the answers to date 7/19/2017:3:45pm none are working if I do something on the sorts echo exec('start text.bat'); I will get a This is a test to show your batch is working and simply just have echo ..... in the batch file the main issue I am having is the server is not physically showing the opened file like displaying the GUI lets just take notepad for example
I can open notepad and get some return value as long as my batch file closes notepad once its finished running however the GUI for notepad is never displayed and thats very important
I read in a few articles about using apache as a service which im pretty sure I am but I do know that xaammp has suffiecient priveleges and I have checked the box that says "Allow apache to interact with desktop" however no GUI is popping up thats the main point I guess im trying to get across is I need to display the GUI not just open the file as a background service.
If it makes answering easier I am open to switching programming languages if theres one that can do what I want easier
Your theory is correct, it will run on the server however you may have issues running applications directly from php (with this method afaik it does not detach from the PHP, and the webapp "hangs" while the application is running).
Make sure: return values are printed / logged. Just an
<?php
if(isset($_POST['startServer'])){
echo exec('batch/startServer.bat');
}
?>
Could point you to the right direction. The exec function may have been disabled in your distribution.
Using
<?php
instead of
<?
is highly advised, by default short_tags are not enabled in most distributions (wamp, xamp, etc).
Set debug mode and print everything to get information about the problem:
<?php
ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);
if(isset($_POST['startServer'])){
echo exec('batch/startServer.bat');
}
?>
If you don't have any response, try a simple batch file with a "hello world" to test if it works.
Be aware, the rights and limitations are comes from the php environment, the batch file inherits the same rights running the PHP code / Apache (in case of mod_php)
In php manual about exec function, there is a note :
Note: If a program is started with this function, in order for it to
continue running in the background, the output of the program must be
redirected to a file or another output stream. Failing to do so will
cause PHP to hang until the execution of the program ends.
I think "hangs like the application is loading" is your application waiting for the bat file terminated / closed to get the output result
Let's try another approach, i found it here, the concept is to create a scheduler that execute the program you want and call it using command.
hope this help :
shell_exec('SCHTASKS /F /Create /TN _notepad /TR "notepad.exe" /SC DAILY /RU INTERACTIVE');
shell_exec('SCHTASKS /RUN /TN "_notepad"');
shell_exec('SCHTASKS /DELETE /TN "_notepad" /F');
If this doesn't work
Check whether you have declared safe_mode = Off inside php.ini
From here:
How do you run a .bat file from PHP?
Have you tried:
system("cmd /c C:[path to file]"); ?
You might need to run it via cmd, eg:
system("cmd /c C:[path to file]");
Or Try following options
1.
<?php
exec('c:\WINDOWS\system32\cmd.exe /c START C:\Program Files\VideoLAN\VLC\vlc.bat');
?>
2.
When you use the exec() function, it is as though you have a cmd terminal open and are typing commands straight to it.
Use single quotes like this $str = exec('start /B Path\to\batch.bat');
The /B means the bat will be executed in the background so the rest of the php will continue after running that line, as opposed to $str = exec('start /B /C command', $result); where command is executed and then result is stored for later use.
<?php
pclose(popen("start /B test.bat", "r")); die();
?>
i think this is a containment issue.
if you run the app under the process of php run by iiswebuser when php terminates it will close all spawned child processes in windows. there is a very quick way a command to break an application out of the child process containment using the start command.
if(isset($_POST['startServer'])){
exec('start batch/startServer.bat');
}
Diagram of containment as i explained it (simplisticly)
IIS (IIS runs as an IISUser)
php (application)
cmd.exe (batch)
using start bring it to the root of that tree
IIS (IIS runs as an IISUser)
php (application)
cmd.exe (batch)
Baim Wrong was correct in the first part of the response: you have to redirect output of the script or your PHP code will hang. Also, you have to move process in the background.
This is easy to do on *nix:
system("/usr/local/bin/shell.sh >> /tmp/log.log 2>&1 &");
I know that you can redirect the output on Windows but not sure how to move the process in the background. You should check DOS manual or try with power shell.
you can use either system or exec php function
$path = __DIR__ . '/batch/startServer.bat';
exec('cmd /c start ' . $path);
or
$path = __DIR__ . '/batch/startServer.bat';
$lastLine = system('cmd /c start ' . $path);
You are having some issue about running application directly from exec. I was having the same issue of running file using exec. It was solved by passing another parameter 2>&1.
exec('some_command 2>&1', $output);
print_r($output); // to see the response to your command
Check the values printed by output see exec function
<?php
ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);
$output = array();
if(isset($_POST['startServer'])){
exec('batch/startServer.bat 2>&1', $output);
print_r($output);
} else {
echo "Not posted";
}
?>
I am wanting to execute a large, database intensive script, but do not need to wait for the process to finish. I would simply like to call the script, let it run in the background and then redirect to another page.
EDIT:
i am working on a local Zend community server, on Windows 7.
I have access to remote linux servers where the project also resides, so i can do this on linux or windows.
i have this
public function createInstanceAction()
{
//calls a seperate php process which creates the instance
exec('php -f /path/to/file/createInstance.php');
Mage::getSingleton('adminhtml/session')->addSuccess(Mage::helper('adminhtml')->__('Instance creation process started. This may take up to a few minutes.'));
$this->_redirect('instances/adminhtml_instances/');
return;
}
this works perfectly, but the magento application hangs around for the process to finish. it does everything i expect, logging to file from time to time, and am happy with how its running. Now all i would like to do is have this script start, the controller action does not hang around, but instead redirects and thats that. from what I have learnt about exec(), you can do so by changing the way i call exec() above, to :
exec('php -f /path/to/file/createInstance.php > /dev/null 2>&1 &');
which i took from here
if i add "> /dev/null 2>&1 &" to the exec call, it doesnt wait around as expected, but it does not execute the script anymore. Could someone tell me why, and if so, tell me how i can get this to work please?
Could this be a permission related issue?
thanks
EDIT : Im assuming it would be an issue to have any output logged to file if i call the exec function with (/dev/null 2>&1 &) as that would cancel that. is that correct?
After taking time to fully understand my own question and the way it could be answered, i have prepared my solution.
Thanks to all for your suggestions, and for excusing my casual, unpreparedness when asking the question.
The answer to the above question depends on a number of things, such as the operating system you are referring to, which php modules you are running and even as far as what webserver you are running. So if i had to start the question again, the first thing i would do is state what my setup is.
I wanted to achieve this on two environments :
1.) Windows 7 running Zend server community edition.
2.) Linux (my OS is Linux odysseus 2.6.32-5-xen-amd64 #1 SMP Fri Sep 9 22:23:19 UTC 2011 x86_64)
to get this right, i wanted it to work either way when deploying to windows or linux, so i used php to determine what the operating system was.
public function createInstanceAction()
{
//determines what operating system is Being used
if (strtoupper(substr(PHP_OS, 0, 3)) === 'WIN')
{
//This is a windows server
//call a seperate php process to run independently from the broswer action
pclose(popen("start php /path/to/script/script.php","r"));
}
else
{
//assuming its linux, but in fact it simply means its not windows
// to check for linux specifically use (strtoupper(substr(PHP_OS, 0, 3)) === 'LIN')
exec('php -f /path/to/file/script.php >/dev/null 2>&1 &');
}
//the browser will not hang around for this process to complete, and you can contimue with whatever actions you want.
//myscript log any out put so i can capture info as it runs
}
In short, ask questions once you understand them. there are many ways to to achieve the above, and this is just one solution that works for my development and production environments.
thanks for the help all.
PHP popen
From the docs (this should help you do other stuff, while that process is working; not sure if closing the current PHP process will kill the opened process):
/* Add redirection so we can get stderr. */
$handle = popen('/path/to/executable 2>&1', 'r');
echo "'$handle'; " . gettype($handle) . "\n";
$read = fread($handle, 2096);
echo $read;
pclose($handle);
Solution 2:
Trick the browser to close the connection (assuming there is a browser involved):
ob_start();
?><html><!--example html body--></html><?php
$strContents=ob_get_clean();
header("Connection: Close");
header("Content-encoding: none");//doesn't work without this, I don't know why:(
ignore_user_abort(true);
header("Content-type: text/html");
header("Content-Length: ".strlen($strContents));
echo $strContents;
flush();
//at this point a real browser would close the connection and finish rendering;
//crappy http clients like some curl implementations (and not only) would wait for the server to close the connection, then finish rendering/serving results...:(
//TODO: add long running operations here, exec, or whatever you have.
You could write a wrapper-script, say createInstance.sh like
#! /bin/bash
trap "" SIGHUP
php -f "$1" > logfile.txt 2>&1 &
Then you call the script from within PHP:
exec('bash "/path/to/file/createInstance.sh"');
which should detach the new php process most instantly from the script. If that doesen't help, you might try to use SIGABRT, SIGTERM or SIGINT instead of SIGHUP, I don't know exactly which signal is sent.
I've been able to use:
shell_exec("nohup $command > /dev/null & echo $!")
Where $command is for example:
php script.php --parameter 1
I've noticed some strange behavior with this. For example running mysql command line doesn't work, only php scripts seem to work.
Also, running cd /path/to/dir && php nohup $command ... doesn't work either, I had to chdir() within the PHP script and then run the command for it to work.
The PHP executable included with Zend Server seems to be what's causing attempts to run a script in the background (using the ampersand & operator in the exec) to fail.
We tested this using our standard PHP executable and it worked fine. It's something to do with the version shipped with Zend Server though our limited attempts to figure out what that was going on have not turned anything up.
Basically my situation is as follows.
Upload file
Run external process on file (which generates another file)
When external process is down, process the generated file.
Currently in PHP I run the program as follows:
$cmd = 'cd the_directory/; ./the_program'
system($cmd);
The program runs fine and everything, but the program at the end says "Press Enter to exit..." And thus Apache is hanging indefinitely as this program is waiting for user input. Our partner declares that they have this program integrated into their backend flawlessly and does not experience this issue. Up until now all external programs that i have executed in PHP exit without requiring user input which seems to be the norm for this situation.
It seems to me that the code should just simply not have the end message requiring user input. Am I missing something? Or is there a way to get around this? Or do they just need to change their code?
Thanks!
I think you should try proc_open.
With it you can not only execute an external command as a process, but also set pipes to get and send information to that process.
Take a close look to the third parameter of this function, and study the example in the PHP manual for this function, where you can see something like this:
fwrite($pipes[0], '<?php print_r($_ENV); ?>');
so, you can write what you need to the input pipe of the process you've just opened.
if you use Windows environment:
$run_cmd = "cmd /c c:/app_folder/app.exe";
$WshShell = new COM("WScript.Shell");
$oExec = $WshShell->Run($run_cmd, 0, false);
Note that the latter will cause the process window to close on end
If you use UNIX (haven't tested it myself yet):
exec('\app_folder\app &');
I have a PHP website and I would like to execute a very long Python script in background (300 MB memory and 100 seconds). The process communication is done via database: when the Python script finishes its job, it updates a field in database and then the website renders some graphics, based on the results of the Python script.
I can execute "manually" the Python script from bash (any current directory) and it works. I would like to integrate it in PHP and I tried the function shell_exec:
shell_exec("python /full/path/to/my/script") but it's not working (I don't see any output)
Do you have any ideas or suggestions? It worths to mention that the python script is a wrapper over other polyglot tools (Java mixed with C++).
Thanks!
shell_exec returns a string, if you run it alone it won't produce any output, so you can write:
$output = shell_exec(...);
print $output;
First off set_time_limit(0); will make your script run for ever so timeout shouldn't be an issue. Second any *exec call in PHP does NOT use the PATH by default (might depend on configuration), so your script will exit without giving any info on the problem, and it quite often ends up being that it can't find the program, in this case python. So change it to:
shell_exec("/full/path/to/python /full/path/to/my/script");
If your python script is running on it's own without problems, then it's very likely this is the problem. As for the memory, I'm pretty sure PHP won't use the same memory python is using. So if it's using 300MB PHP should stay at default (say 1MB) and just wait for the end of shell_exec.
A proplem could be that your script takes longer than the server waiting time definied for a request (can be set in the php.ini or httpd.conf).
Another issue could be that the servers account does not have the right to execute or access code or files needed for your script to run.
Found this before and helped me solve my background execution problem:
function background_exec($command)
{
if(substr(php_uname(), 0, 7) == 'Windows')
{
pclose(popen('start "background_exec" ' . $command, 'r'));
}
else
{
exec($command . ' > /dev/null &');
}
}
Source:
http://www.warpturn.com/execute-a-background-process-on-windows-and-linux-with-php/
Thanks for your answers, but none of them worked :(. I decided to implement in a dirty way, using busy waiting, instead of triggering an event when a record is inserted.
I wrote a backup process that runs forever and at each iteration checks if there is something new in database. When it finds a record, it executes the script and everything is fine. The idea is that I launch the backup process from the shell.
I found that the issue when I tried this was the simple fact that I did not compile the source on the server I was running it on. By compiling on your local machine and then uploading to your server, it will be corrupted in some way. shell_exec() should work by compiling the source you are trying to run on the same server your are running the script.