umask 1 user commands nosh umaskchange permissions mask then chain umask mask next-prog Most shells have a built-in umask command that does not chain and has additional interactive functionality. See the manual for each individual shell for its built-in command. This command is more commonly used with exec1 and nosh1. umask is a chain-loading utility that changes its permissions mask to mask and then chain loads to next-prog with the execvp3 function. next-prog may contain its own command line options, which umask will ignore. The mask is a number, and follows the C language conventions. Conventionally masks are specified in octal, which in the C language is specified by a leading 0. Jonathan de Boyne Pollard