umask
NAME
umask - The user file-creation mask is set to modeSYNOPSIS
umask [-p] [-S] [mode]
DESCRIPTION
The user file-creation mask is set to mode. If mode begins with a digit, it is interpreted as an octal number; otherwise it is interpreted as a symbolic mode mask similar to that accepted by chmod(1). If mode is omitted, the current value of the mask is printed. The -S option causes the mask to be printed in symbolic form; the default output is an octal number. If the -p option is supplied, and mode is omitted, the output is in a form that may be reused as input. The return status is 0 if the mode was successfully changed or if no mode argument was supplied, and false otherwise.
SEE ALSO
This is extracted from the main bash man page, see there for more details.