File Permissions

UNIX File Permissions

UNIX files all belong to a specific user and group, and each file can be read, written (edited) or executed

Using the

ls -l

command will produce an output that looks like this

-rw-------  1 jsmith      81405 Nov  3  1995 aporepressor.pdb
drwxr-xr-x  2 wang          512 Feb 13  1996 bio227
-rw-r--r--  1 james        3168 Jun 25 23:14 blast.matrix
-rw-r--r--  1 ldw          4336 Jun 24 14:11 ceu44902.seq
-rw-rw-r--  1 test        19379 Jul 31 11:16

The first group of characters indicate the type of file and the permissions associated with it.

The first character indicates whether the item is a file or a directory.

The next three characters are the permissions for the owner of the file, after that come the permissions for everyone in the Owner's group, and then finally, the last 3 characters indicate the permissions for everybody else who has an account on the computer system.

The chmod command allows you to change the file permissions to allow only specific people to view your files and directories.

For more help with UNIX file permissions, check out the ls or the chmod commands.