Question

1

How to make php webpage to access the file in /root directory?

rated 0 times [ 1] [ 0] / answers: 1 / hits: 19639 / 1 Year ago, fri, february 3, 2023, 10:42:24

I am using Linux 12.04,apache and php is installed on it.I want to access a text file in /root/ folder.I am really confused with the permissions.The php script i m using

<?php

$file = fopen("/root/cr.txt", "r") or exit("Unable to open file!");

//Output a line of the file until the end is reached



while(!feof($file))

  {

  echo fgets($file). "<br>";

  }



fclose($file);

?>

This script is able to access the file /var/www folder but not able to access /root/ip.txt file. Please help and explain step to step possible.

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antoccasiona

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3 Years ago

answered 1 Year ago berlorful · Accepted Answer

I will forget about the security implications of doing this and will go down to business:

If you have done ls -l /var/www and ls -l /root you would have noticed that both has different permissions:

$ ls -l /root/cr.txt

total 2

-rw-r-----  1 root root    0 Jul  9 01:28 cr.txt

$ ls -l /var/www

total 2

-rw-r--r--  1 www-data www-data    0 Jul  9 01:28 somefile

The /root is only readable for root, while /var/www is readable by www-data user. Now, if you check apache process you will notice that it's running using the www-data user.

$ ps aux | grep apache
www-data 5133 0.0 0.2 6512 1208 ? R+ 10:04 0:00 apache

Now, you are trying to make apache running with the www-data user read the file. You can take three courses of action:

Move the file to /var/www and change it's permissions so www-data users can read it.
```
mv /root/cr.txt /var/www/

chown www-data:www-data /var/www/cr.txt
```
This is the preferable method.

Create a symlink to the file in the /var/www directory:
```
ln -s /root/cr.txt /var/www/
```
This won't ensure that your file is being read, in some cases.

This is dangerous and should not be done! Add the www-data user to the root group, or change the file ownership so it could be read by www-data users:
```
chown :www-data /root/cr.txt

## Or

sudo adduser www-data root
```
This shouldn't be done if you don't understand the risks!