The umask() function sets the process's file mode creation mask to cmask and returns the previous value of the mask. Only the access permission bits of cmask and the file mode creation mask are used. The mask is inherited by child processes. See intro(2) for more information on masks.

The previous value of the file mode creation mask is returned.

See attributes(5) for descriptions of the following attributes:

mkdir(1), sh(1), intro(2), chmod(2), creat(2), mknod(2), open(2), stat(3HEAD), attributes(5)