Asking a Yes/No Question from a Bash Script

“The function is pretty simple it accepts a couple of options
and the remainder of the arguments are presumed to be the question
text. It prompts the user for an answer and validates that the
answer is one of “yes”, “y”, “no”, or “n”. The answer is converted
to lower case so any combination of case is accepted.

“The available options are –timeout N which causes the prompt
to timeout after N seconds, and –default ANS which provides a
default answer for prompts that timeout. It also allows the user to
hit ENTER and accept the default answer. The function code
follows:”

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