Shell Data Processing - Command

About

command in a shell may have one of the following functions in a pipeline.

• a start command to create a input stream
  • from a file
  • from an terminal input or text
• a filter command to process a input stream and create an output stream
• a terminal command - to end the pipeline by:
  • saving the stream on disk (ie in a file)
  • or printing it on the terminal

Management

• Redirection of stream