usage: ./ask -q QUESTION -a ANSWER_CHARS [-n]

Options:
  -q QUESTION, --question=QUESTION
       Ask user QUESTION
  -a ANSWER_CHARS, --answer-chars=ANSWER_CHARS
       Use each character of ANSWER_CHARS as a valid answer to QUESTION
  -n, --newline
       Print a newline immediately after QUESTION and ANSWER_CHARS
  -h, --help
       Display this message and exit
  -v, --version
       Display version information and exit

To obtain the answer given by the user, use the program's
return code. For each given character of ANSWER_CHARS corresponds
an integer value of 0-n.

For example, if ANSWER_CHARS is the string "ynrq", valid return
values would come to be y=0, n=1, r=2, and q=3.

A negative return value indicates an error occurred.

Example on the command line:
   user@host$ ask -q "Would you like to continue" -a ynq
   Would you like to continue? [y/n/q] q
   user@host$ echo $?
   2
   user@host$