Unix in a Nutshell, 4th Edition

Name

umask

Synopsis

    umask [value]

Print the current value of the file creation mode mask , or set it to value, a three-digit octal code specifying the read-write-execute permissions to be turned off when new files are created. Normally used in .login or .profile. umask is a built-in command in the Bash, Korn, and C shells (see Chapters 4 and 5).

umask number	File permission	Directory permission
0	rw-	rwx
1	rw-	rw-
2	r--	r-x
3	r--	r--
4	-w-	-wx
5	-w-	-w-
6	---	--x
7	---	---

Examples

Turn off write permission for others:

    umask 002                Produces file permission -rw-rw-r--

Turn off all permissions for group and others:

    umask 077                Produces file permission -rw-------

Note that you can omit leading zeroes.