Edit /etc/resolv.conf using PHP

Question

I want to add new DNS on my server. I'm able to edit the file /etc/resolv.conf using vi editor.

But, when I try using PHP.. the file is not opening.

What could be the issue?

Please suggest / provide me with a solution to fix this.

it might be because of permissions, check permissions of the /etc/resolv.conf, before running your code. — A human being, May 13 '13 at 10:18

score 2 · Accepted Answer · edited May 23 '17 at 12:21

2

Most likely your PHP is running on a different user then when you login to the server yourself. You will have read/write access to the file and PHP doesnt.

Now increasing the rights of the PHP users could cause a security issue, so I would advise against it. But you could grant the user access to that specific file only if realy needed. Check Granting Access Permission to a file to a specific user on how to do it.

edited May 23 '17 at 12:21

Community

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answered May 13 '13 at 10:15

Hugo Delsing

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Thanks.. I used chown to grant the permissions and it worked for me. :) – KiranD May 13 '13 at 10:38

score 0 · Answer 2 · answered May 13 '13 at 10:17

You will probably need root access to modify /etc/hosts .

You can chmod 666 /etc/hosts, but this would be a security issue.
But so is running PHP under root,
and so is chowning the /etc/hosts.

So there you have 3 (insecure) solutions. With the last one being least evil.

You might also be facing a struggle with PHP accessing files if PHP is restricted to files inside a certain directory. ( http://www.php.net/manual/en/ini.core.php#ini.open-basedir )

Edit /etc/resolv.conf using PHP

2 Answers2