CLI
Warum CLI
- Flexibel
- Transparent
Principles
- Benutzerfreundlichkeit
- Human readable
- Verwendung nicht nur von anderen Programmen
- Einfache Bausteine
- Kombinieren von kleinen, einfachen Programmen zu groesserem System
- Pipes und Filterarchitektur
- Kombinierbar durch stdin/stdout/stderr, signals, exit-codes
- Konsistenz über Programme hinweg
- Bereits bestehenden Mustern folgen
- Intuitiv
- Robustheit
- Falscher input muss korrekt behandelt werden
Guidelines
- Use a command-line argument parsing library where you can
- Return zero exit code on success, non-zero on failure.
- Send output to stdout
- Send messaging to stderr
- Display help text when passed no options, the -h flag, or the --help flag
- Display a concise help text by default
- A description of what your program does
- One or two example invocations.
- Descriptions of flags
- Display help for Subcommands (like
git commit --help) - In help text, link to the web version of the documentation
- Lead with examples
Output
- Human-readable output is paramount
- Have machine-readable output where it does not impact usability
- If human-readable output breaks machine-readable output, use --plain to display output in plain, tabular text format for integration with tools like grep or awk
- If you change state, tell the user.
- Make it easy to see the current state of the system
- Use color with intention
- Disable color if your program is not in a terminal or the user requested it