From exec() manual page:
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.
So, it seems i should redirect output to something and add ampersand under Linux, to make my script truly running in background.
How i'm supposed to "translate" /dev/null and & for Windows? Any chance to use php:// to make it OS safe?
exec('php ' . __DIR__ . '/script.php > /dev/null &');
$WshShell = new COM("WScript.Shell");
$oExec = $WshShell->Run("cmd /C dir /S %windir%", 0, false);
Related
I'm running a php socket. I run the program through nohup. Run this program properly through root. But my problem is running the program via the exec () function in php. When I run the command this way the program runs correctly but the program output is not printed in nohup.out.
my command in ssh:
nohup php my_path/example.php & #is working
my command in user php:
exec('nohup php my_path/example.php >/dev/null 2>&1 &', $output); #not update nohup.out
please guide me...
From PHP docs on exec:
If a program is started with this function, in order for it to continue running in the background, the output of the program must be redirected to a file or another output stream. Failing to do so will cause PHP to hang until the execution of the program ends.
From man nohup:
If standard input is a terminal, redirect it from /dev/null. If standard output is a terminal, append output to 'nohup.out' if possible, '$HOME/nohup.out' otherwise. If standard error is a terminal, redirect it to standard output. To save output to FILE, use 'nohup COMMAND > FILE'.
To satisfy both - redirect manually to nohup.out:
exec('nohup php my_path/example.php >>nohup.out 2>&1 &', $output);
Is there a way to end this background process executed by this code?
$process = exec('nohup java -jar '/selenium-server-standalone-3.8.0.jar -> /dev/null &');
I am simply running a jar file which is a server, I need to stop this server after some code is executed, is there a way to end it? something like
end($process);
die($process);
To launch your background process, use a command like this:
exec('nohup java jar "/selenium-server-standalone-3.8.0.jar" > /dev/null 2>&1 & echo $!', $pid);
This is redirecting stdout to /dev/null, and then stderr to stdout so that the process can actually continue in the background. After that, it is returning the processid of the new background process and saving it in $pid.
Then, later, you can stop it with exec('kill '.$pid);
I am using this code on Ubuntu 13.04,
$cmd = "sleep 20 &> /dev/null &";
exec($cmd, $output);
Although it actually sits there for 20 seconds and waits :/ usually it works fine when using & to send a process to the background, but on this machine php just won't do it :/
What could be causing this??
Try
<?PHP
$cmd = '/bin/sleep';
$args = array('20');
$pid=pcntl_fork();
if($pid==0)
{
posix_setsid();
pcntl_exec($cmd,$args,$_ENV);
// child becomes the standalone detached process
}
echo "DONE\n";
I tested it for it works.
Here you first fork the php process and then exceute your task.
Or if the pcntl module is not availabil use:
<?PHP
$cmd = "sleep 20 &> /dev/null &";
exec('/bin/bash -c "' . addslashes($cmd) . '"');
The REASON this doesn't work is that exec() executes the string you're passing into it. Since & is interpreted by the shell as "execute in the background", but you don't execute a shell in your exec call, the & is just passed along with 20 to the /bin/sleep executable - which probably just ignores that.
The same applies to the redirection of output, since that is also parsed by the shell, not in exec.
So, you either need to find a way to fork your process (as described above), or a way to run the subprocess as a shell.
My workaround to do this on ubuntu 13.04 with Apache2 and any version of PHP:
libssh2-php, I just used nohup $cmd & inside a local SSH session using PHP and it ran it just fine the background, of course this requires putting certain security protocols in place, such as enabling SSH access for the webserver user, so it would have exec-like permissions then only allowing localhost to login to the webserver ssh account.
How to execute a php script from another ?
I want to execute 3 php scripts from my php file without waiting for the 3 scripts to finish. In other words, the 3 php files need to be executed all at once (parallel) instead of one-by-one (sequentiell).
The 3 scripts are in the same folder of my main php file (script).
If you do not want to wait for them to finish, run them with either
exec('php script.php &> /dev/null &');
shell_exec('php script.php &> /dev/null &');
system('php script.php &> /dev/null &');
`php script.php &> /dev/null &`
Any of those should accomplish the job, depending on your PHPs configuration. Although they are different functions, their behaviour should be similar since all output is being redirected to /dev/null and the proccess is immediately detached.
I use the first solution in a production environment where a client launches a bash SMSs sending script which can take up to 10 minutes to finish, it has never failed.
More info in: http://php.net/exec · http://php.net/shell_exec · http://php.net/system
how about using exec("php yourscript.php")
do consider using queuing system to store your php script names and worker to fetch data from queue and do the execution e.g. beanstalkd
You need to run them as detached jobs, and it is not really easy - or portable. The usual solution is to use nohup or exec the scripts with stdout and stderr redirected to /dev/null (or NUL in Windows), but this often has issues.
If possible, make the three scripts available as scripts on the web server, and access them through asynchronous cURL functions. This has also the advantage of being able to test the scripts through the browser, and supplying you the scripts output.
Other ways include using popen(), or if under Linux, the at or batch utility.
taken from http://board.phpbuilder.com/showthread.php?10351142-How-can-I-exec%28%29-in-a-non-blocking-fashion:
In order to execute a command have have it not hang your php script while it runs, the program you run must not output back to php. To do this, redirect both stdout and stderr to /dev/null, then background it.
> /dev/null 2>&1 &
In order to execute a command and have it spawned off as another process that is not dependent on the apache thread to keep running (will not die if somebody cancels the page) run this:
exec('bash -c "exec nohup setsid your_command > /dev/null 2>&1 &"');
For windows http://www.php.net/manual/en/function.exec.php:
function execInBackground($path, $exe, $args = "") {
global $conf;
if (file_exists($path . $exe)) {
chdir($path);
if (substr(php_uname(), 0, 7) == "Windows"){
pclose(popen("start \"bla\" \"" . $exe . "\" " . escapeshellarg($args), "r"));
} else {
exec("./" . $exe . " " . escapeshellarg($args) . " > /dev/null &");
}
}
To the shell_exec, add the '/B' parameter, this allows you to run several executables at once.
See my answer at this question: PHP on a windows machine; Start process in background
It's the same.
shell_exec('start /B "C:\Path\to\program.exe"); /B parameter is key
here. I tried to find the topic for you again, but I can't seem to
find it anymore. This works for me.
I hope this solves the problem for you.
I have a command I want to run, but I do not want PHP to sit and wait for the result.
<?php
echo "Starting Script";
exec('run_baby_run');
echo "Thanks, Script is running in background";
?>
Is it possible to have PHP not wait for the result.. i.e. just kick it off and move along to the next command.
I cant find anything, and not sure its even possible. The best I could find was someone making a CRON job to start in a minute.
From the documentation:
In order to execute a command and have it not hang your PHP script while
it runs, the program you run must not output back to PHP. To do this,
redirect both stdout and stderr to /dev/null, then background it.
> /dev/null 2>&1 &
In order to execute a command and have
it spawned off as another process that
is not dependent on the Apache thread
to keep running (will not die if
somebody cancels the page) run this:
exec('bash -c "exec nohup setsid your_command > /dev/null 2>&1 &"');
You can run the command in the background by adding a & at the end of it as:
exec('run_baby_run &');
But doing this alone will hang your script because:
If a program is started with exec 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.
So you can redirect the stdout of the command to a file, if you want to see it later or to /dev/null if you want to discard it as:
exec('run_baby_run > /dev/null &');
This uses wget to notify a URL of something without waiting.
$command = 'wget -qO- http://test.com/data=data';
exec('nohup ' . $command . ' >> /dev/null 2>&1 & echo $!', $pid);
This uses ls to update a log without waiting.
$command = 'ls -la > content.log';
exec('nohup ' . $command . ' >> /dev/null 2>&1 & echo $!', $pid);
I know this question has been answered but the answers i found here didn't work for my scenario ( or for Windows ).
I am using windows 10 laptop with PHP 7.2 in Xampp v3.2.4.
$command = 'php Cron.php send_email "'. $id .'"';
if ( substr(php_uname(), 0, 7) == "Windows" )
{
//windows
pclose(popen("start /B " . $command . " 1> temp/update_log 2>&1 &", "r"));
}
else
{
//linux
shell_exec( $command . " > /dev/null 2>&1 &" );
}
This worked perfectly for me.
I hope it will help someone with windows. Cheers.
There are two possible ways to implement it.
The easiest way is direct result to dev/null
exec("run_baby_run > /dev/null 2>&1 &");
But in case you have any other operations to be performed you may consider ignore_user_abort
In this case the script will be running even after you close connection.
"exec nohup setsid your_command"
the nohup allows your_command to continue even though the process that launched may terminate first. If it does, the the SIGNUP signal will be sent to your_command causing it to terminate (unless it catches that signal and ignores it).
On Windows, you may use the COM object:
if(class_exists('COM')) {
$shell = new COM('WScript.Shell');
$shell->Run($cmd, 1, false);
}
else {
exec('nohup ' . $cmd . ' 2>&1 &');
}