Provided by: libowfat-dev_0.30-2ubuntu1_amd64 
NAME
io_waitread - read from a descriptor
SYNTAX
#include <io.h>
int io_waitread(int64 fd,char* buf,int64 len);
DESCRIPTION
io_waitread tries to read len bytes of data from descriptor fd into buf[0], buf[1], ..., buf[len-1]. (The
effects are undefined if len is 0 or smaller.) There are several possible results:
• o_waitread returns an integer between 1 and len: This number of bytes was available for immediate
reading; the bytes were read into the beginning of buf. Note that this number can be, and often is,
smaller than len; you must not assume that io_waitread always succeeds in reading exactly len bytes.
• io_waitread returns 0: No bytes were read, because the descriptor is at end of file. For example, this
descriptor has reached the end of a disk file, or is reading an empty pipe that has been closed by all
writers.
• io_waitread returns -3, setting errno to something other than EAGAIN: No bytes were read, because the
read attempt encountered a persistent error, such as a serious disk failure (EIO), an unreachable
network (ENETUNREACH), or an invalid descriptor number (EBADF).
SEE ALSO
io_nonblock(3), io_waitread(3), io_waitreadtimeout(3) io_waitread(3)