Click this button to go to the index for this section.

umask(2)
NAME
  umask - Sets and gets the value of the file creation mask

SYNOPSIS
  #include <sys/types.h>

  #include <sys/stat.h>

  mode_t umask (
	  mode_t cmask );

STANDARDS
  Interfaces documented on this reference page conform to industry standards
  as follows:

  umask():  POSIX.1, XPG4, XPG4-UNIX

  Refer to the standards(5) reference page for more information about
  industry standards and associated tags.

PARAMETERS
  cmask	    Specifies the value of the file mode creation mask.

DESCRIPTION
  The umask() function sets the file mode creation mask of the process to the
  value of the cmask parameter and returns the previous value of the mask.
  The cmask parameter is constructed by logically ORing file permission bits
  defined in the sys/mode.h header file.

  Whenever a file is created (by the open(), mkdir(), or mknod() function),
  all file permission bits set in the file mode creation mask are cleared in
  the mode of the created file. This clearing lets users restrict the default
  access to their files.

  The mask is inherited by child processes.

RETURN VALUES
  Upon successful completion, the previous value of the file mode creation
  mask is returned.

RELATED INFORMATION
  Commands:  chmod(1), mkdir(1), Bourne shell sh(1b), POSIX shell sh(1p),
  umask(1)

  Functions:  chmod(2), mkdir(2), mknod(2), open(2), stat(2)


  Standards:  standards(5)