umask.1 (2010 09)

umask(1) umask(1)

RETURN VALUE

umask exits with one of the following values:

0 The ﬁle mode creation mask was successfully changed or no mask operand was supplied.

>0 An error occurred.

EXAMPLES

In these examples, each line show an alternate way of accomplishing the same task.

Set the umask value to produce read and write permissions for the ﬁle’s owner and read permissions for

all others (ls -l displays -rw-r--r-- on newly created ﬁles):

umask u=rwx,g=rx,o=rx

symbolic mode

umask a=rx,u+w symbolic mode

umask 022 numeric mode

Set the

umask value to produce read, and write permissions for the ﬁle’s owner, read-only for others

users in the same group, and no access to others (

-rw-r-----):

umask a-rwx,u+rw,g+r

symbolic mode

umask u=rw,g=r,o= symbolic mode

umask ,u+rw,g+r symbolic mode

umask 137 numeric mode

Set the

umask value to deny read, write, and execute permissions to everyone (----------

umask a= symbolic mode

umask 777 numeric mode

Add the write permission to the current mask for everyone (there is no equivalent numeric mode):

umask a+w symbolic mode

WARNINGS

If you set a mask that prevents read or write access for the user (owner), many programs, such as editors,

that create temporary ﬁles will fail because they cannot access the ﬁle data.

DEPENDENCIES

The

umask command is implemented both as a separate executable ﬁle (/usr/bin/umask

) and as

built-in shell commands.

POSIX Shell and Separate File

All features are supported (see sh-posix (1)). The numeric mask display uses a minimum of two digits.

Korn Shell

The

-S option is not supported in the Korn shell built-in command (see ksh (1)). The numeric mask

display uses a minimum of two digits.

C Shell

The

-S option and symbolic mask values are not supported in the C shell built-in command (see csh(1)).

The numeric mask display uses a minimum of one digit.