Problem with HTML and PHP

[cherault]

Hi all,

Working with:

• Linux Debian
• Lighttpd Server
• PHP7.0

I want to launch some shell scripts pressing HTML buttons. All the files are placed in /var/www/html The rights are done by:

sudo chown www-data:www-data /var/www/

So, I wrote a very simple code:

HTML test code (index.html):

<form action="openApp.php">
    <input type="submit" value="Open Script">
</form>

PHP test code (openApp.php):

<?php
    exec('test.sh');
    header('Location: http://localhost/index.html?success=true');
?>

But no luck, nothing is working.

Note that the shell script just create an empty file like that:

touch /home/$USER/testFile

Also, my Lighttpd configuration file is like that:

server.modules = ( "mod_access", "mod_alias", "mod_compress", "mod_fastcgi", "mod_redirect", )

May be I am wrong with that piece of code. Do I need some Javascript to do the job ? May be the rights are wrong ?

Could you help me please ? I am stuck with that.

Thank you for your help and support

[luisrosety]

Have you checked permissions for Apache user? (Usually www-data user)
What happens if you try creating the file with PHP file command?
 

<?php
$handle = fopen("yourPathToTheFile", "w");
?>

Also check if you are running PHP in safe mode.
 

[cherault]

Thanks for your reply and proposition.

Unfortunately, it doesn't work.
I am not using Apache but Lighttpd, I think it is similar.
Do you know how to check the safe mode in PHP ?
Is it in php.ini ?

I will check that point and get back to you.

One more time thanks.

[cherault]

I tried your solution, but I am stuck with that.
Nothing works !
 

If my HTML page is like that with the post method:

<form action="openApp.php" method="post">
    <input type="submit" value="Open Script">
</form>

Is that correct to call the PHP script ?
Or maybe using type=button is better than submit ?

All the files (HTML, SHELL and PHP) are managed by the www-data user.
Is that correct too ?

Another point:

When I go to /var/www/html, and launching just my PHP script:

cd /var/www/html
php openApp.php

the script works fine, and write something in a file text like this:

<?php
	$myfile = fopen("/home/$USER/file.txt", "w") or die("Unable to open file!");
    $txt = "writing test\n";
    fwrite($myfile, $txt);
	fclose($myfile);
?>

But when I use the HTML page, nothing works.
So I deduce that is a permission access problem right ?
Because the PHP script works, and the HTML works too.
So, where I am wrong ?

Edited December 6, 2019 by cherault

[luisrosety]

Have you enabled lighttpd log?
It can provide very useful information.

[cherault]

Not yet, but I will do it asap.

Thanks for the info

[dsonesuk]

Try step by step

1. give submit a name attribute with value, and check if openApp.php can read value, using $_GET or $_POST which ever you use at the time.

Edited December 6, 2019 by dsonesuk

[cherault]

This is the logs...I have some problems with the rights access:

COMMAND  PID     USER   FD      TYPE DEVICE SIZE/OFF NODE NAME
lighttpd 716 www-data  cwd   unknown                      /proc/716/cwd (readlink: Permission denied)
lighttpd 716 www-data  rtd   unknown                      /proc/716/root (readlink: Permission denied)
lighttpd 716 www-data  txt   unknown                      /proc/716/exe (readlink: Permission denied)
lighttpd 716 www-data NOFD                                /proc/716/fd (opendir: Permission denied)

 

[cherault]

Thanks dsonesuk, I will get a try to see what is going on

[cherault]

Ok, doesn't work...I don't what to do.
I though it xas simple to build an HTML interface to write some data within a text file, but it isn't !!!!
This is why I love C++ 😉

More seriously, is there is a way to understand what's going on with HTMl and PHP.
I admit i'm really stuck with that !!!

Thanks for your help and support

[dsonesuk]

try adding full path to php file in action, just in case its relative path issue. 

[cherault]

Ok, I tried your solution like this:

<?php
	$myfile = fopen("/var/www/html/newfile.txt", "w") or die("Unable to open file!");
    $txt = "testwriting\n";
    fwrite($myfile, $txt);
	fclose($myfile);
?>

The HTML file is like that:

<!DOCTYPE html>
<html>
<head>
<style>
</style>
</head>
<body>
<form action="openApp.php">
    <input type="submit" name ="value" value="Open Script">
</form
</body>
</html>

But it still doesn't work.

The access are the next:

-rw-r--r-- 1 www-data www-data  173 déc.   6 12:53 index.html
-rw-r--r-- 1 www-data www-data    0 déc.   6 12:34 newfile.txt
-rwxrwxr-x 1 www-data www-data  174 déc.   6 13:06 openApp.php

What do you think about this ?

[luisrosety]

Try adding these lines at the beginning of your PHP script:

ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);

 

[cherault]

Thanks Luisrosety,

I did it but nothing appears...

The php script is :

<?php
	ini_set('display_errors', 1);
	ini_set('display_startup_errors', 1);
	error_reporting(E_ALL);

    exec("/home/$USER/script");
?>

Is it possible that the web browser (Firefox) block some informations ?

Edited December 6, 2019 by cherault

[Ingolme]

You should use single-quotes in the exec() command, otherwise it thinks that $USER is a PHP variable. I would expect the above code to throw an error similar to "Undefined variable $USER".

[cherault]

Thanks Ingolme for the info. But it doesn't solve my problem.

I am sure the HTML and PHP code are correct.
When I launch the PHP in console mode, everything works fine.

But when I launch it through HTML...nothing happen.
So, I suppose there is some problems with the permissions, of Firefox is blocking something....I really don't know.
I just want to activate a shell script from an html button...I must be easy no ?
 

[luisrosety]

I have tried the following:
1.The php that directly writes the file on the same directory (/home/pi/www/test).

2.  Navigate with the browser to the directory http://myserver/test and the file is not created and php gives the error: 

Warning: fopen(file.txt): failed to open stream: Permission denied in /home/pi/www/html/test/index.php on line 6
Unable to open file!

 

3. Then I give "rwx" permission to others:

chmod o+wx /home/pi/www/test

4. Then going to the same directory http://myserver/test the file gets created

The php file (index.php)

<?php 
    ini_set('display_errors', 1);
    ini_set('display_startup_errors', 1);
    error_reporting(E_ALL);

    $myfile = fopen("file.txt", "w") or die("Unable to open file!");
    $txt = "writing test\n";
    fwrite($myfile, $txt);
    fclose($myfile);
?>

I have done the tests with lighttpd.
Launching the creation of the file directly with the script gives more information.
You must have permission issues.

[cherault]

Hi Luisrosety,

Thank you for the help.

I did all the steps you gave me, but no luck.
Who is the user in /home/pi/www/test ?
Is it root or www-data ?

Actually, I delete and reinstall lighttpd and php7.0.
The actual permissions and owner are root.
Do I need to move to www-data like that :

sudo chown -R www-data:www-data /var/www/html

or

sudo chown -R <user>:www-data /var/www/html

 

Edited December 7, 2019 by cherault

[cherault]

Ok, some news from my tests:

I did that:

sudo usermod -a -G www-data <user>
sudo chgrp -R www-data /var/www/html/
sudo chmod -R g+w /var/www/html/

After these modifications, when I launch the php script, I saw :

Notice: Use of undefined constant  - assumed '' in /var/www/html/test.php on line 9

But the file was written in /var/www/html
So I can say this solve the problem partially.

Whatever, Thank you to all of you for your time, help and support

Regards,

 

[cherault]

At least, one question:

Using the base of the php script for writing a file, and using the same HTML page:

PHP (test.php):

<?php 
    ini_set('display_errors', 1);
    ini_set('display_startup_errors', 1);
    error_reporting(E_ALL);

    $myfile = fopen("file.txt", "w") or die("Unable to open file!");
    $txt = "writing test\n";
    fwrite($myfile, $txt);
    fclose($myfile);
?>

HTML (index.html):

<!DOCTYPE html>
<html>
<head>
<style>
</style>
</head>
<body>
<form action="test.php" method="POST">
    <input type="submit" name="Envoyer" value="Open Script">
</form
</body>
</html>

I tried to modify the PHP file to launch a shell script :

SHELL (test.sh)

#!/bin/bash

cd /home/$USER/Prog/C++/Debug/
./test

exit 0

So my PHP file look like this:

PHP (test.php)

<?php 
    ini_set('display_errors', 1);
    ini_set('display_startup_errors', 1);
    error_reporting(E_ALL);

	exec("test.sh");
	header('Location: http://localhost/index.html?success=true');
?>

But it doesn't work !
I have the same permissions as before, so the rights access are corrects.
So I think it comes from the PHP script, but I don't know why it doesn't work.

Do you have an idea ?

Thanks for all

[luisrosety]

What happens when to access directly the php document with your browser?
Let's say your path to the php document is 
 

http://localhost/test.php

What happens if you access this document like this instead of launching it with the form?

Edited December 8, 2019 by luisrosety

[cherault]

Unfortunately it doesn't work !
Even if I put the files inside /var/www/html...no luck.

What kind of permissions do I need to set to be able to activate a shell script which will launch a program outside /var/www/html ?

[luisrosety]

Quote

 

Have a look at this discussion

[cherault]

Thank you for the informations.