exec() function working in cron but not manually - php

I'm controlling my home automation with a Raspberry Pi and webserver. I use this line to turn on my lights (sending an RC signal to wireless power socket).
exec("sudo ./../../../home/pi/wiringPi/examples/lights/action 63 A on");
This is working when the script is ran by a cron job, but when I manually want to execute this command (using a php form and buttons), it does not work. I tried adding $output, $return); and checking $return, and that confirms the exec() function is not executed. However, when I use something like exec("whoami");, the script is executed.
What is it about my command that makes it work only in cron jobs? I had this working once, don't know what happened. Manually sending the command via ssh in the terminal is working normally.

Fix permissions on this command and run it without sudo (for ubuntu default php user is www-data, for suse wwwrun, ...).
Check the path also. I recommend absolute paths.

Related

PHP shell_exec won't call Windows 10 bash script

I'm running a CakePHP project under XAMPP (Apache) on Windows 10 Anniversary Update.
Apache is running under my user account.
The app calls several external processes via shell_exec(): ImageMagick, phantomjs execute as expected.
I also want to call a bash script, that in turn calls ImageMagick under Ubuntu bash (installed separately, via apt-get). I've had to adjust all paths into a form that bash can resolve.
bash /mnt/e/Projects/project-name/website/bin/crop_to_aspect.sh 1 1
/mnt/e/Projects/project-name/website/webroot/images/agent_photo/tmp_ed564289-a6f6-45b7-b9f3-2aec2b8bb3d1.jpg
/mnt/e/Projects/project-name/website/webroot/images/agent_photo/ed564289-a6f6-45b7-b9f3-2aec2b8bb3d1.jpg```
The command fails when called via shell_exec(). The same command, written to CakePHP's log, and then called from a cmd.exe prompt, works perfectly.
Thinking it may have been a path issue, I wrapped the same script in a windows batch file, including the full path to bash. I called the full batch file path, ie:
#echo off
SET aw=%1
SET ah=%2
SET in=%3
SET out=%4
C:\Windows\System32\bash.exe /mnt/e/Projects/project-path/website/bin/crop_to_aspect.sh %aw% %ah% %in% %out%
This script is then called:
E:\Projects\project-path\website\bin\crop_to_aspect.bat 4 3
/mnt/e/Projects/project-path/website/webroot/images/listing_photo/tmp_ed564289-a6f6-45b7-b9f3-2aec2b8bb3d1.jpg
/mnt/e/Projects/project-path/website/webroot/images/listing_photo/ed564289-a6f6-45b7-b9f3-2aec2b8bb3d1.jpg
Once again, the command executes correctly in cmd.exe but does nothing when run via shell_exec() from the PHP script.
Check if a function is not in the list of functions disabled in php.ini (disable_functions) line

Using PHP Exec() command to run WINRS / WINRM cmd

Platform Details: IIS7, PHP5, Windows Server 2008
Server Name: server1
I'm attempting to use php's exec() function to execute a .bat file which has the following command:
winrs -r:server2 "C:\custom_functions.bat"
However, when I execute that command, it does not work. When running the custom_functions.bat file directly on server2, it works fine therefore, the problem is not likely to be my code. I'm guessing its a permissions error.
When I execute exec("whoami"), it returns "nt authority\network service" as the user.
If I execute any basic windows commands through php exec() function such as exec("ipconfig") or exec("dir c:\"), they work fine. The problem comes when I'm trying to use WINRM to execute a command on a remote server. I have used php's system() function as well - with same results.
Please help!?
To run a command on a server, you need authorization on that server. When you run the command manually from the prompt, you have access through your user account.
When IIS runs the command, it runs as a build in user, that has no access to server2.
I do not advise to give the webserver process access to server2.

Executing commands in php as root user in arch linux

i am using arch linux. i want to execute the php file which changes the ip of the system. i did
ifconfig eth0 192.168.163.137
in the terminal and it works fine. the same i tried doing with
shell_exec('ifconfig eth0 192.168.163.137');
in a php file and tried opening the page from a remotely located web browser from another pc connected via router. teh page displays nothing and the code also doesnt execute. i guess its the problem with the user executing it.apache is executing it. so i want it to be run by the root.can anyone please guide me to the execution of my code. i even installed sudo and just put
shell_exec('sudo ifconfig......');
it too doesnt execute...please help...thanku..:)
Sudo normally requires an interactive shell to enter your password. That's obviously not going to happen in a PHP script. If you're sure you know what you're doing and you've got your security issues covered, try allowing the Apache user to run sudo without a password, but only for certain commands.
For example, adding the following line in your sudoers file will allow Apache to run sudo without a password, only for the ifconfig command.
apache ALL=NOPASSWD: /sbin/ifconfig
Adjust the path and add any arguments to suit your needs.
Caution:
There might still be complications due to the way PHP calls shell commands.
Remember that it's very risky to allow the web server to run commands as root!
Probably a better alternative:
Write a shell script with the suid bit to make it run as root no matter who calls it.
shell_exec
This function is disabled when PHP is running in safe mode.
Documentation : http://php.net/manual/en/function.shell-exec.php
So, maybe try tweaking your php.ini file?
Write the commands to a queue and have cron pick them up, validate them (only allow known good requests), and run them, then mark that queue complete with the date and result.
Your end-user can then click/wait for update using ajax.

PHP shell_exec() issue

I am having an issue using the PHP function shell_exec().
I have an application which I can run from the linux command line perfectly fine. The application takes several hours to run, so I am trying to spawn a new instance using shell_exec() to manage better. However, when I run the exact same command (which works on the command line) through shell_exec(), it returns an empty string, and it doesn't look like any new processes were started. Plus it completes almost instantly. shell_exec() is suppose to wait until the command has finished correct?
I have also tried variations of exec() with the same outcome.
Does anyone have any idea what could be going on here?
There are no symbolic links or anything funky in the command: just the path to the application and a few command line parametes.
Some thing with you env
See output of env from cli (command line interface) and php script
Also see what your shell interpreter?
And does script and cli application runs from one user?
If so, se option safe_mode
Make sure the user apache is running on (probably www-data) has access to the files and that they are executable (ls -la). A simple chmod 777 [filename] would fix that.
By default PHP will timeout after 30 sec. You can disable the limit like this:
<?php
set_time_limit(0);
?>
Edit:
Also consider this: http://www.rabbitmq.com/

Trouble running subversion through PHP's exec

I can run an svn command from the command line but not from within a PHP script. Significantly, I can run the PHP script on my Mac and it returns the expected data just fine but when I upload it to my Linux server it won't work (from within PHP... I can run the svn command from the terminal). I'm pretty sure this is a user or permission issue of some sort.
I can run (from command line):
svn log http://whatever.com/svn/foo
but none of the following work (run separately... not all together like this):
exec('svn log http://whatever.com/svn/foo');
exec('svn log http://whatever.com/svn/foo',$out);
exec('/usr/bin/svn log http://whatever.com/svn/foo');
However this works:
exec('ls');
I assume the problem is that when I run from the command line I am running as root whereas when I run from PHP I am running as the apache user (www-data)? Perhaps? Any suggestions on how to be able to run exec('svn log http://whatever.com/svn/foo');?
Changing permissions to 777 (just trying to get it working!) does not help.
Here are a couple of threads that I think might help:
Thread 1 (read as there is more):
$cmd = '/usr/bin/svn list --config-dir /some/place file:///var/subversion/devfoundry/ 2>&1';
exec($cmd, $output);
$output = implode("\n", $output) . "\n";
echo $output;
Thread 2:
The Subversion error "svn: Can't
recode string" can be caused by the
locale being wrong. Try
<?php
putenv('LANG=en_US.UTF-8');
?>
(or whatever your preferred locale is)
before you call shell_exec()
Thread 3: PHP Interactive Shell
May be you can use a svn client for php. Here is a good one
http://code.google.com/p/phpsvnclient/
When you run Subversion from the command line, you are running it as yourself. That is, you are the user logged in and running the command.
If you are running Php from a webpage, it is the user who is running the Apache httpd daemon (which could be "apache", "www", "runwww", etc. depending upon the platform). The user running the PHP script may not have read/write permissions to the Subversion repository.
You have two ways of solving this:
Provide your program with user credentials via the --username and --password command line parameters.
Setup the user running httpd with Subversion credentials. Once it is done, it'll never have to be done again. This way, your PHP code doesn't contain login credentials.

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