• Allow data to flow between two Process (进程) or among Thread in a single process in a uni-directional manner. One party writes to the pipe, and the other reads from it
  • Sort of Pseudo-file that can be used to connect 2 Process
  • Direct one’s output to another’s input

3 Default Pipe Channels

Under the POSIX

  1. stdin: File Descriptor is 0
  2. stdout: File Descriptor is 1
  3. stderr: File Descriptor is 2