I've written a bash script that launches a browser on an xServer and takes a screenshot of the browsers.
If I run it with the apache2 user (www-data) its working flawless, even when i use the php interactive shell and run it via shell_exec or exec its working perfectly.
However when I run it from my php file via browser it does not seem to work properly.
The script does not seems to run the xterm command (for launching the browser) and takes no screenshots, it only executes sleep and kill commands. I spent the whole day looking for a solution or at least a proper way to debug but i cant seem to fid anything
Turn on errors to start with
error_reporting(E_ALL);
ini_set('display_errors', '1');
Then change your command to
shell_exec('bash /home/daemon/daemon.sh');
The last part of your command pipes all output (including errors) to /dev/null - E.g to no where so you will not see any errors at all.
Do this and re-run the command and you should see errors.
Related
I use php (7.3.7) to run an octave script on a web server (iis on windows 10).
In particular the octave script solves a set of differential equations and produces a text file.
The php script is the following:
<?php
system('cd C:\inetpub\wwwroot\BRwebapp\ && "C:\Octave\Octave-5.1.0.0\octave.vbs" --no-gui --persist compart.m');
?>
Strangely enough, the command:
C:\inetpub\wwwroot\BRwebapp\ && "C:\Octave\Octave-5.1.0.0\octave.vbs" --no-gui --persist compart.m
runs fine when executed on cmd and produces the desired output (.txt file).
The php script, however, hangs. The browser (I have tried both Chrome and Firefox) is just loading with no results (not displaying any errors in the console). I have also used exec() instead on system(), with no results. I have verified that php works (by using <?php phpinfo(); ?>).
Any ideas?
Thanks a lot!
UPDATE I have finally solved this issue by following the instructions
presented here by Marle1:
Foo.cmd won't output lines in process (on website)
I need to run a PHP script which is scraping a website for data, and I need to run it on my VPS which has linux. I want to run it as a task so that I should be able to logout of my VPS and the script should keep running in background.
I've read about CRON job but it's more for like scheduling and repetitive tasks; but I need the PHP script only once.
Is there a way in PHP to do that? Please help, I'm just a newbie to this.
Thanks in advance! :)
I've tried it as a CRON job, but it doesn't seem to serve my exact purpose.
so I run my script like this from terminal.
php scrapethewebsite.php
and then it show this
Started scraping at 10:03:00 20-03-2019
and I can't logout or close my vps/ssh connection.
I look for
php scrapethewebsite.php
Started scraping at 10:03:00 20-03-2019
and then I should be able to logout or close my connection. And then I should be able to shutdown my PC and go for a walk..
Yes, You can do this with the screen. The screen is most of the time already installed in Linux VPS. but still, you can get by command.
apt-get install screen
Its give you the ability to have multiple screens in VPS where you can run multiple tasks at the same time.
LIke you have.
Get a screen with command.
screen -S sessionname
sessionname will be ur screen name.
and you can dispach it with command/
CTRL + A, followed by D.
then you can close your putty or any tool from via you accessing your vps.
here you go.
for more information, you can follow this link.
Screen in Linux
Run this in your SSH session, then you can click X and close it and it will still run
nohup php scrapethewebsite.php >/dev/null 2>&1 &
to check if your file is running type this command
top
you should see the php file up there and press spacebar to update the list
_____________________________________________________________________
If your php script has some error from time to time or just runs out of execution time and you want to re-run it when it closes down.. you have to create a .sh file with a while loop inside it and run nohup on it so it will re-run the php file after it errors up.
If you want to use nohup on php file that needs to re-run from time to time, then you should do the following
$ echo 'while true ; do php scrapethewebsite.php ; done > /dev/null' > ~/php_run_loop.sh
$ chmod a+x ~/php_run_loop.sh
$ nohup ~/php_run_loop.sh
NOTE: If you have an error or other problem in your php script, this will cause it to run over and over again without any limit, forever.
Scanline is a simple command line utility used for scanning documents from a twain scanner. http://blog.scottkleper.com/scanline-command-line-scanner-for-mac/
I am trying to use Scanline through a PHP script using shell_exec(); the same way that I would use it directly from the terminal in MacOS.
When I run Scanline directly from the command line, it detects all the attached scanners and prints them out ./scanline -list
When I run Scanline using shell_exec(), it does not detect any devices.
So far, I have changed the apache user to my local user, and have added the local user to the sudoers file. If I run 'whoami' in shell_exec() it is the same result as if I run it in command line.
I have printed the environment using printenv in command line, and have setup all of the same variables in my php script before executing shell_exec() using putenv(); If I run shell_exec('printenv 2>&1'), it is the exact same environment as when I run printenv in command line.
All the permissions are correct and allow access, and scanline runs when executed through shell_exec() without error (I checked apache's error logs, as well as put a error_reporting(E_ALL); in the top of the PHP file to printout any issues along the way). The only difference in how the program is executed is that in command line the devices are detected, and run through shell_exec(), no devices are found.
Any ideas as to what else I could be missing between command line and using shell_exec() ?
I also tried using system(), exec(), and shell_exec() interchangeably with the same result.
I have a php webpage located on Webserver1, which is from Host1.
I also have a bash script located in Gameserver1 which is from Host2.
Is there any way to send a command from Webserver1 to Gameserver1 to execute the bash file? The webpage and file are on different VPSs. Both are running Debian 7.
The script is literally one line, to execute a java command via a screen, so the server can start if a player notices it's down. The command's available already so it doesn't need to be a secure way of hiding what the command is.
There are 2 ways I can think of. either create a bash file in Webserver1 that connects through ssh and executes the bash script you need on Gameserver1. then run it through php with exec() command.
Or you can create a php file in Gameserver1 that uses exec() to execute the bash script you need on Gameserver1 and call it using file_get_contents() on Webserver1, which is not that secure since anyone can call that file and run your script.
I am trying to run a php script on my remote Virtual Private Server through the command line. The process I follow is:
Log into the server using PuTTY
On the command line prompt, type> php myScript.php
The script runs just fine. BUT THE PROBLEM is that the script stops running as soon as I close the PuTTY console window.
I need the script to keep on running endlessly. How can I do that? I am running Debian on the server.
Thanks in advance.
I believe that Ben has the correct answer, namely use the nohup command. nohup stands for nohangup and means that your program should ignore a hangup signal, generated when you're putty session is disconnected either by you logging out or because you have been timed out.
You need to be aware that the output of your command will be appended to a file in the current directory named nohup.out (or $HOME/nohup.out if permissions prevent you from creating nohup.out in the current directory). If your program generates a lot of output then this file can get very large, alternatively you can use shell redirection to redirect the output of the script to another file.
nohup php myscript.php >myscript.output 2>&1 &
This command will run your script and send all output (both standard and error) to the file myscript.output which will be created anew each time you run the program.
The final & causes the script to run in the background so you can do other things whilst it is running or logout.
An easy way is to run it though nohup:
nohup php myScript.php &
If you run the php command in a screen, detach the screen, then it won't terminate when you close your console.
Screen is a terminal multiplexer that allows you to manage many processes through one physical terminal. Each process gets its own virtual window, and you can bounce between virtual windows interacting with each process. The processes managed by screen continue to run when their window is not active.