.TH io_wantread 3
.SH NAME
io_wantread \- signal that you want to read from a descriptor
.SH SYNTAX
.B #include <io.h>

void \fBio_wantread\fP(int64 fd);
.SH DESCRIPTION
io_wantread tells the next io_wait() that you want to read from this
descriptor.  Call io_dontwantread() again if you change your mind.

The next time you call io_wait(), it will look whether this descriptor
becomes readable, too.  You can then use io_canread() to check whether
the descriptor has become readable.

You have to have called io_fd on the descriptor first (io_pipe and
io_socketpair do this 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.
.SH "SEE ALSO"
io_wait(3), io_canread(3), io_wantread(3), io_fd(3)