pipe – two–way interprocess communication

bind #| dir


An attach(5) of this device allocates two new cross–connected I/O streams, dir/data and dir/data1.

Data written to one channel becomes available for reading at the other. Write boundaries are preserved: each read terminates when the read buffer is full or after reading the last byte of a write, whichever comes first.

Writes are atomic up to the iounit(2), typically 65536 bytes, that is, each write will be delivered in a single read by the recipient, provided the receiving buffer is large enough.

If there are multiple writers, each write is guaranteed to be available in a contiguous piece at the other end of the pipe. If there are multiple readers, each read will return data from only one write.

The pipe(2) system call performs an attach of this device and returns file descriptors to the new pipe's data and data1 files. The files are open with mode ORDWR.

pipe(2), iounit(2)