umask
User's file creation mask. Set the shell process's 
  file creation mask to mode.
SYNTAX
      umask [mode]
OPTIONS
      mode      The file creation mask, in octal.
The current value of the mask will be printed if mode is omitted,
 Examples
  Example values for the mask:
  002, gives all access to the group and read and execute access to others, 
  022, gives read and execute access to the group and others.
  
  The return status is zero if the mode is successfully changed or if no mode 
  argument is supplied, and non-zero otherwise. 
  
  Note that when the mode is interpreted as an octal number, each number of the 
  umask is subtracted from 7. Thus, a umask of 022 results 
  in permissions of 755. 
This is a tcsh shell command.
  
  "Woe to him who doesn't know how to wear his mask, be he king or Pope!" 
  - Luigi Pirandello
Related commands:
  
  chmod - Change access permissions
  chown - Change file owner and group
  
  Equivalent BASH command:
  
  umask - file creation mask