NAME

       io_fd - prepare descriptor for io_wait

SYNTAX

       #include <io.h>

       int io_fd(int64 fd);

DESCRIPTION

       If  you  want  to  use  io_canread()  and  io_canwrite()  on a descriptor, you have to use
       io_wait() on it first, and io_wait() has to know which descriptors you are interested  in.
       Use io_fd() for this.

       io_pipe and io_socketpair already call io_fd for you.

       Waiting  on  descriptors  only  works  for  sockets, fifos and pipes.  It may also work on
       devices and TTYs, but that is platform dependent -- you should not rely on that.  It  does
       not work on files.

RETURN VALUE

       io_fd returns 1 on success, 0 on error.

SEE ALSO

       io_wait(3), io_wantread(3), io_canread(3), io_eagain(3), io_nonblock(3)

                                                                                         io_fd(3)