Words like permissions or access are too vague for a Unix system. In order to solve your problem, you would need to learn how permissions are managed, and then define more precisely what you mean by "not able to access it".
Short overview of the permission system on Unix
There are 3 kinds of permissions:
Note that the permission have special meaning for directories:
r: list the files in the directory, for instance with
w: add new elements to the directory.
x: access files in the directory.
There are 3 levels of permission you can set:
- user (the owner of the file/directory)
Note that when you create new users on the system, you're asked to assign them a group. The reason is simply for a better management of permissions.
How to know the permissions of a file
There are various ways. I think the most straightforward would be using
ls -l. Example:
$ ls -l file
-rw-r----- 1 rahmu users 406 Jun 18 13:28 file
The first column indicates the permissions.
-rw-r-----, the first bit (
-) indicates whether the file is a directory, a link or a regular file. Ignore it for now. Then the next 3 bits (
rw-) indicate the user-level permissions. That means user
rahmu has the right to
write this file. The next three bits (
r--) are the group-level permissions, this means that all the users who are in the group
users will have
read access. All the other users will have no permission at all (
--). That means they cannot read the file, write it, nor execute it.
How to modify permissions.
It is usually done with the
chmod utility. It supports many syntax, which one is best is debatable, but the following will make most sense after the above explanation:
$ chmod [who]operator[permissions] file
others. (there's also
all, for modifying all three levels at once).
chmod u-w file: remove
write permission for user.
chmod a+x file: add
execute permission for all.
How to prevent access to your /home?
As I mentioned, you need to define what you mean by access. If what you mean is
read access, as in you don't want them to even list what's inside your directory, then the easiest would be to take the appropriate permissions off the
/home directory. (Assuming they're connecting with a separate user).
$ chmod o-rwx ~