NAME
     umask - set file creation mode mask

SYNOPSIS
     #include <sys/types.h>
     #include <sys/stat.h>

     mode_t
     umask(mode_t numask);

DESCRIPTION
     The umask() routine sets the process's file mode creation mask to numask
     and returns the previous value of the mask.  The 9 low-order access per-
     mission bits of numask are used by system calls, including open(2),
     mkdir(2),  and mkfifo(2),  to turn off corresponding bits requested in
     file mode.  (See chmod(2)).  This clearing allows each user to restrict
     the default access to his files.

     The default mask value is S_IWGRP|S_IWOTH (022, write access for the own-
     er only).  Child processes inherit the mask of the calling process.

RETURN VALUES
     The previous value of the file mode mask is returned by the call.

ERRORS
     The umask() function is always successful.

SEE ALSO
     chmod(2),  mknod(2),  open(2)

STANDARDS
     The umask() function call is expected to conform to IEEE Std 1003.1-1988
     (``POSIX'').