mode_t
umask(
mode_t numask
)
)
routine sets the process's file mode creation mask to
numask
and returns the previous value of the mask.
The 9 low-order access permission bits of
numask
are used by system calls, including
open(2),
mkdir(2),
mkfifo(2)
and
mknod(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 owner only). Child processes inherit the mask of the calling process.
)
function is always successful.
)
function conforms to
ISO/IEC 9945-1:1990 (``POSIX.1'') .