UNIX Ownerships and Permissions

Setting ownerships and permissions requires root privileges on UNIX systems or administrator privileges on Windows systems. On UNIX, use the commands chown, chgrp, and chmod to set ownerships and permissions.

UNIX permission modes are specified by a series of three octal numbers. These three numbers assign access privileges to user, group, and other, respectively.

In each user, group, and other field, the following values provide the following permissions:

Value    Permissions
7 read, write, and execute
6 read and write
5 read and execute
4 read only

The UNIX command ls -l will return the permissions, ownerships, file size, and modification date of a file or directory. For example:

ls -l  /usr2/bsmith/fio_seq


-rw-r--r--  1 bsmith  general  4870 Jan 18 2005  

For details regarding UNIX file permission masks and the use of chown, chgrp, and chmod, see your UNIX operating system manuals.