umask: umask [-p] [-S] [mode]

Display or set file mode mask.

Sets the user file-creation mask to MODE. If MODE is omitted, prints the current value of the mask.

If MODE begins with a digit, it is interpreted as an octal number; otherwise it is a symbolic mode string like that accepted by chmod(1).

Options
-p if MODE is omitted, output in a form that may be reused as input -S makes the output symbolic; otherwise an octal number is output

Exit Status:
Returns success unless MODE is invalid or an invalid option is given.