Redirect output AND errors to one file
Cheat sheet · 11 commands
Pipes & redirection
Every command has one input and two outputs: stdin, stdout and stderr. Redirection points them at files; pipes connect one command's output to the next one's input. This page is that whole model on one sheet.
The 3 you will use every day
Pipe: output of cmd1 becomes input of cmd2
Run cmd2 only if cmd1 succeeded
The full sheet
- Write output to a file (replaces contents)
- Append output to a file
- Redirect only errors
- Redirect output AND errors to one file
- Discard error messages
- Pipe: output of cmd1 becomes input of cmd2
- See it live and save a copyguide ›
- The correct way to append to a root-owned fileguide ›
- Run cmd2 only if cmd1 succeeded
- Run cmd2 only if cmd1 failed
- Compare the output of two commandsguide ›
Practise these for real in the interactive course,
or keep every sheet, chapter and fix in one book: The Linux Command Line Handbook.