Executing Linux commands from webpage

I have set up a very basic website on apache2 server (running on Ubuntu 18.04). The website has just one page. I used some JavaScript to add dynamic content to it, and the website contains HTML form, which sends data to MySql server -- I connected to the database with PHP.

Based on user input, I need to execute a certain Linux terminal command (say: ls -l). For example, if user inputs first and last names and clicks on Submit button, the ls -l command will automatically execute without user doing anything in terminal. Is this possible?
This is the HTML form I have:

ls -l

ls -l

<form method="post">
<label>Fisrt Name: <input type="text" name="firstname" required></label>
<label>Last Name: <input type="text" name="lastname" required></label>
<input type="submit" name="submit" value="Submit">
</form>


Edited:
Ok so I have this PHP code right now in addition to code that connects to MySql database:

<?php
$output = shell_exec('sudo addgroup test2');
echo "<pre>$output</pre>;

$result = exec('echo $?');
echo "$result";
?>


However, it does not add this group and echo $? returns 0. However, when I substitute shell_exec('sudo addgroup test2'); with shell_exec('ls -l'); -- it works fine. What am I doing wrong?

echo $?

shell_exec('sudo addgroup test2');

shell_exec('ls -l');

so, ls -l will be run on the server - so you'd need to show how you intend to do that in server side code
– Jaromanda X
Jun 30 at 5:33

ls -l

So I do not really know yet how to do that in server side code. I need some guidance
– tera_789
Jun 30 at 5:35

php.net/manual/en/function.exec.php
– Jaromanda X
Jun 30 at 5:35

Thanks. So this code will be run on the server the website is hosted, correct?
– tera_789
Jun 30 at 5:37

which code? you haven't shown any code
– Jaromanda X
Jun 30 at 5:38

1 Answer
1

This need to be handled by the backend server code running behind Apache. You may pass the commands as a query string or as POST json from UI and write a server-side script (in php) to catch the parameters and execute the function as shell-exec http://php.net/manual/en/function.shell-exec.php .

shell-exec

Please check the Edited part
– tera_789
Jun 30 at 6:07

Try this snippet. <?php $output = shell_exec('touch /tmp/created_from_php'); echo("<pre>$output</pre>"); ?> To verify check /tmp/created_from_php path after executing.
– Prabuddha Chakraborty
Jun 30 at 6:13

<?php $output = shell_exec('touch /tmp/created_from_php'); echo("<pre>$output</pre>"); ?>

/tmp/created_from_php

A reason for sudo addgroup test2 is the user php is running may not have sudo/root priveledge. Like if you are running php with www-data user then it may not have sudo access.
– Prabuddha Chakraborty
Jun 30 at 6:15

sudo addgroup test2

sudo/root

www-data

sudo

Replace above shell_exec function with simple sudo commands like sudo touch /etc/created_from_php and if it does not work then it is the php user privilege issue.
– Prabuddha Chakraborty
Jun 30 at 6:18

sudo touch /etc/created_from_php

I have tried shell_exec('touch /tmp/created_from_php'); but it did not work out for me. And you are right, it looks like I am running php with www-data user. When I do exec('whoami'); -- it returns www-data
– tera_789
Jun 30 at 6:31

shell_exec('touch /tmp/created_from_php');

www-data

exec('whoami');

www-data

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