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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, XSH4.0, XSH4.2, XSH5.0

  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 a logical OR operation on the file
  permission bits defined in the <sys/mode.h> header file.

  Whenever a file is created (by the open(), mkdir(), mkfifo(), 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. The state of any other bits in that value is unspecified,
  except that a subsequent call to umask() with the returned value as cmask
  will leave the mask in the same as its state before the first call,
  including any unspecified use of those bits.

ERRORS
  No errors are defined.

SEE ALSO
  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)

Index for Section 2

Alphabetical listing for U

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