Easy - How to change user permissions

Posted on 2004-10-30
Last Modified: 2013-12-16
Vanilla Debian Install:
Should be very simple. How do I change user permissions?
I know chmod and chown.
You can give user,rights, and other permissions.
How do I specify the actual user that is getting the rights, or the actual group?
In windows you say you want a specific user to have specific rights.

I can type chmod u+w file.txt and that will give write access to the user....which user? The user thats logged in? That's root then.

My problem is I have a webserver, apache. I need to secure all web files but make it so only the root and the user 'ftp' can have full and total access to them.

I did some playing around and probably screwed up the files, so to redo it would be the best.

chmod ugo-rwx /var/backhand/htdocs would take away all access right?
Then I should build up from there to do it correctly. The webuser (www) should have read access, right?, and the root/ftp user should have god rights. I have searched and searched, i think its the concept I don't have.

No one logs into this box besides me with root, i know its bad, and ftp with a client, and www from the internet.
Question by:undy30
    LVL 40

    Accepted Solution

    'chmod u+w file.txt' gives the current owner (user) of the file write permissions. To set the owner you can (as root) use 'chown some-user file.txt'.

    What you probably want to do for the web site content is to execute:

    chown ftp file.html
    chmod 644 file.html

    That will make the site files owned by ftp and readable by group and other. Being readable by other will be necessary for the web server to work.

    Author Comment

    Ok. So that works. But what if I add another use who wants to do updates later?
    Would I make them the owner and then change the rights? Or would I be forced to make a group  and assign them the group rights?

    Also I have many folders, how can I chown them all at once.
    I do chown ftp /var/backhand/* and it works, but it doesn't flow down through each folder.
    LVL 40

    Expert Comment

    There can only be one owner of a file system object. To have multiple users be able to write/delete files you'd want both users to be in the same group and give group write perms (chmod g+w).

    chmod, chown, and chgrp can do recursive options, like 'chgrp -R ...'

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