builtin help umask

shoebill

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.