File status flags are used to specify attributes of the opening of a
file. Unlike the file descriptor flags discussed in File Descriptor Flags, the file status flags are shared by duplicated file descriptors
resulting from a single opening of the file. The file status flags are
specified with the flags argument to open
;
see Opening and Closing Files.
File status flags fall into three categories, which are described in the following sections.
open
and are
returned by fcntl
, but cannot be changed.
open
will do.
These flags are not preserved after the open
call.
read
and
write
are done. They are set by open
, and can be fetched or
changed with fcntl
.
The symbols in this section are defined in the header file fcntl.h.