What CLI APIs are there?

[CanadaHonk]

• argv (process.argv, ~Deno.args, etc)
  • See also #3 for specifying
• stdout (process.stdout.write, etc)
  • console.log does partially cover this; however some applications may need/want a method to write to stdout without additional processing or newlines.
• stdin
• environment variables (too general/out of scope?)
• exit/quit function (too general/out of scope?)
  • Possible signature: exit(code?: number)

[lucacasonato]

• (exit) signal hooks (Deno.addSignalListener for an example)

[Ethan-Arrowood]

• interactive/non-interactive
• color support (NO_COLOR https://no-color.org/)