io_waitread(3) [debian man page]

io_waitread(3)						     Library Functions Manual						    io_waitread(3)

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  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.

       o  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.

       o  io_waitread returns -3, setting errno to something other than EAGAIN: No bytes were read, because the read attempt encountered a persis-
	  tent 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)

io_pipe(3)						     Library Functions Manual							io_pipe(3)

NAME

       io_pipe - create a Unix pipe

SYNTAX

       #include <io.h>

       int io_pipe(int64 pfd[2]);

DESCRIPTION

       io_pipe	creates  a  new UNIX ``pipe.'' The pipe can receive data and provide data; any bytes written to the pipe can then be read from the
       pipe in the same order.

       A pipe is typically stored in an 8192-byte memory buffer; the exact number depends on the UNIX kernel. Bytes are written to the end of  the
       buffer  and  read  from	the beginning of the buffer. Once a byte has been read, it is eliminated from the buffer, making space for another
       byte to be written; readers cannot ``rewind'' a pipe to read old data. Once 8192 bytes have been written to the buffer, the pipe  will  not
       be  ready for further writing until some of the bytes have been read. Once all the bytes written have been read, the pipe will not be ready
       for further reading until more bytes are written.

       io_pipe sets d[0] to the number of a new descriptor reading from the pipe, and sets d[1] to the number of a new descriptor writing  to  the
       pipe.  It then returns 1 to indicate success. If something goes wrong, io_pipe returns 0, setting errno to indicate the error; in this case
       it frees any memory that it allocated for the new pipe, and it leaves d alone.

SEE ALSO

       io_readfile(3), io_createfile(3), io_socketpair(3)

																	io_pipe(3)