At a bare minimum, it should be possible to edit the confirmation prompt and select which of "y" or "n" is the default. Other candidate options include:

• No default: re-prompt on enter without input.
• No "any key": re-prompt for unrecognized input.
• Configurable selections: permit any two characters instead of "y" and "n".
  • Multi-character selections: require the user to type out, e.g., "yes" or "no".
  • Non-binary selections: permit additional options, which return sequential exit codes.

This first implementation should strive to match the behavior of CLI confirmation prompts in utilities such as apt-get. Specificallly, it should print "Confirm? [Y/n]" and accept a line of input:

• Empty input defaults to yes, as indicated by the capital "Y".
• Input starting with upper- or lower-case "y" returns yes.
• All other input returns no.

Return values yes and no are represented by the command's exit code, i.e. 0 for yes and 1 for no (backwards from C because sh), such that the command can be used in tests and conditional expressions:

confirm && echo "Yes" || echo "No"