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io_pipe(3)		   Library Functions Manual		    io_pipe(3)

       io_pipe - create	a Unix pipe

       #include	<io.h>

       int io_pipe(int64 pfd[2]);

       io_pipe creates a new UNIX ``pipe.'' The	pipe can receive data and pro-
       vide 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  fur-
       ther 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

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



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