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I'm running ubuntu 11.10. I want to be able to call a shell script from php and run that script as root. When my php attempts to call the shell script as root --like this:

$output = shell_exec('sudo /var/www/')

I get this error in the apache log:

sudo: no tty present and no askpass program specified

I've changed the owner of the php script to root:root. I've added this line to sudoers:

www-data ALL = NOPASSWD:/var/www/my_script.php

I realize that I'm supposed to comment out this line in sudoers:

Defaults    requiretty

However, there's no such line in my sudoers file. What do I need to do to get past this error?

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You cannot use SUDO or SU in PHP. – Johnson Nov 7 '11 at 22:15
Why can't you ? – João Pinto Nov 8 '11 at 0:09
You can:… – user8290 Jan 4 '12 at 1:51

Your sudoers line is granting access to execute "my_script.php" while your shell_exec is invoking "". When a password is not required, the requiretty option should be irrelevant.

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Use "suexec"... in Ubuntu 10.04 server:

sudo apt-get install apache2-suexec-common

Enable suexec:

sudo a2enmod suexec

Edit the config file to match your site:

sudo -e /etc/apache2/suexec/www-data

Then see Using suEXEC on to configure the Apache config file(s).

Another approach...

Allow the www-data user to run to run program1 and program2 with no password:

sudo visudo

Add to the contents of the sudoers file:

User_Alias WWW_USER = www-data
Cmnd_Alias WWW_COMMANDS = /sbin/program1, /sbin/program2


Yet another is with suPHP

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I recently published a project that allows PHP to obtain and interact with a real Bash shell (as user: apache/www-data or root if needed). Get it here:

After downloading you would simply use the following code:

//Setting the second argument in getShell():
//true will return a shell with root
//false will return a shell with the php execution user
$shell    = \MTS\Factories::getDevices()->getLocalHost()->getShell('bash', true);
$return1  = $shell->exeCmd('/var/www/');
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