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)