io_pipe(3) [debian man page]

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)

PIPE(2) 						      BSD System Calls Manual							   PIPE(2)

NAME

     pipe -- create descriptor pair for interprocess communication

SYNOPSIS

     #include <unistd.h>

     int
     pipe(int fildes[2]);

DESCRIPTION

     The pipe() function creates a pipe (an object that allows unidirectional data flow) and allocates a pair of file descriptors.  The first
     descriptor connects to the read end of the pipe; the second connects to the write end.

     Data written to fildes[1] appears on (i.e., can be read from) fildes[0].  This allows the output of one program to be sent to another pro-
     gram: the source's standard output is set up to be the write end of the pipe; the sink's standard input is set up to be the read end of the
     pipe.  The pipe itself persists until all of its associated descriptors are closed.

     A pipe whose read or write end has been closed is considered widowed.  Writing on such a pipe causes the writing process to receive a SIGPIPE
     signal.  Widowing a pipe is the only way to deliver end-of-file to a reader: after the reader consumes any buffered data, reading a widowed
     pipe returns a zero count.

     The generation of the SIGPIPE signal can be suppressed using the F_SETNOSIGPIPE fcntl command.

RETURN VALUES

     On successful creation of the pipe, zero is returned. Otherwise, a value of -1 is returned and the variable errno set to indicate the error.

ERRORS

     The pipe() call will fail if:

     [EFAULT]		The fildes buffer is in an invalid area of the process's address space.

     [EMFILE]		Too many descriptors are active.

     [ENFILE]		The system file table is full.

SEE ALSO

     sh(1), fork(2), read(2), socketpair(2), fcntl(2), write(2)

HISTORY

     A pipe() function call appeared in Version 6 AT&T UNIX.

4th Berkeley Distribution					 February 17, 2011					 4th Berkeley Distribution