First things first: Standard files

• Standard Output

  • Output of a shell command, e.g. default location of echo or print statements. Can be redirected to a file with > operator, which overwrites its destination
  • echo “Hello, World!” echo “Hello, World!” > file.txt cat file.txt > file2.txt >> operator appends instead of overwrites

• Standard Input

  • Where many commands get their data from.
    • If not provided, bash reads stdin from the terminal
      • One line processed at a time
      • use ^D on a line by itself to indicate end of file.
    • cat > file3.txt
    • Redirect with < operator, e.g. cat < file2.txt

• What does the “cat” command when run alone? Why?

Notes: