opensolaris man page for pipe

pipe(2) 							   System Calls 							   pipe(2)

NAME
       pipe - create an interprocess channel

SYNOPSIS
       #include <unistd.h>

       int pipe(int fildes[2]);

DESCRIPTION
       The  pipe() function creates an I/O mechanism called a pipe and returns two file descriptors, fildes[0] and fildes[1]. The files associated
       with fildes[0] and fildes[1] are streams and are both opened for reading and writing.  The O_NDELAY, O_NONBLOCK, and FD_CLOEXEC	flags  are
       cleared on both file descriptors. The fcntl(2) function can be used to set these flags.

       A  read	from  fildes[0] accesses the data written to fildes[1] on a first-in-first-out (FIFO) basis and a read from fildes[1] accesses the
       data written to fildes[0] also on a FIFO basis.

       Upon successful completion pipe() marks for update the st_atime, st_ctime, and st_mtime fields of the pipe.

RETURN VALUES
       Upon successful completion, 0 is returned. Otherwise, -1 is returned and errno is set to indicate the error.

ERRORS
       The pipe() function will fail if:

       EMFILE	 More than {OPEN_MAX} file descriptors are already in use by this process.

       ENFILE	 The number of simultaneously open files in the system would exceed a system-imposed limit.

ATTRIBUTES
       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |Async-Signal-Safe 	   |
       +-----------------------------+-----------------------------+

SEE ALSO
       sh(1), fcntl(2), fstat(2), getmsg(2), poll(2), putmsg(2), read(2), write(2), attributes(5), standards(5), streamio(7I)

NOTES
       Since a pipe is bi-directional, there are two separate flows of data. Therefore, the size (st_size) returned by a  call	to  fstat(2)  with
       argument   fildes[0]  or  fildes[1]  is the number of bytes available for reading from fildes[0] or fildes[1] respectively. Previously, the
       size (st_size) returned by a call to fstat() with argument fildes[1] (the write-end) was the number of bytes  available	for  reading  from
       fildes[0] (the read-end).

SunOS 5.11							    23 Apr 2002 							   pipe(2)