umask - Sets and gets the value of the file creation mask
mode_t umask (
mode_t cmask );
Interfaces documented on this reference page conform to industry standards
umask(): POSIX.1, XPG4, XPG4-UNIX
Refer to the standards(5) reference page for more information about indus-
try standards and associated tags.
cmask Specifies the value of the file mode creation mask.
The umask() function sets the file mode creation mask of the process to the
value of the cmask parameter and returns the previous value of the mask.
The cmask parameter is constructed by logically ORing file permission bits
defined in the sys/mode.h header file.
Whenever a file is created (by the open(), mkdir(), or mknod() function),
all file permission bits set in the file mode creation mask are cleared in
the mode of the created file. This clearing lets users restrict the default
access to their files.
The mask is inherited by child processes.
Upon successful completion, the previous value of the file mode creation
mask is returned.
Commands: chmod(1), mkdir(1), Bourne shell sh(1b), POSIX shell sh(1p),
Functions: chmod(2), mkdir(2), mknod(2), open(2), stat(2)