select replacement - for fun

#!/bin/bash
#
# A replacement for bash's "select" builtin command
# (exercise only - not meant to be taken too seriously)
#
# Copyright (C) 2011 Rodrigo Silva (MestreLion) <[email protected]>
# License: GPL v3 or later, at your choice. See <http://www.gnu.org/licenses/>
#


PS3="Choose an option (0 to quit): " # custom prompt (or comment for default)


# ----- PARAMETERS ---------------------------------------------------------

# From help select:
# select: select NAME [in WORDS ... ;] do COMMANDS; done
#    Select words from a list and execute commands.

unset WORDS NAME
declare -a WORDS=("AAA" "BBB" "CCC") # place options inside (...), blank for "$@"
declare    NAME="option"             # name your output var


# ----- SELECT/IN/DO STATEMENT - DO NOT EDIT --------------------------------

menu() {
    for i in ${!WORDS[@]}; do
        printf "%*d) %s\n" $(((${#WORDS[@]}/10)+1)) $((i+1)) "${WORDS[i]}"
    done;
}
(( ${#WORDS[@]} )) || WORDS=("$@")
while menu && read -rp "$PS3" REPLY && NUMREPLY=""; do
    [[ "$REPLY" != *[![:digit:]]* ]] && NUMREPLY=$((10#$REPLY)) # avoid 08 error
    (( NUMREPLY )) && declare "$NAME"="${WORDS[NUMREPLY-1]}" || declare "$NAME"=""


# ---- INSIDE THE LOOP - EDITABLE -------------------------------------------

# Run your COMMANDS

# Do whatever you want, but of course, dont mess with WORDS, NAME or NUMREPLY
# (remember those those are "inner" vars). But messing with REPLY
# or with your named variable is allowed

    [[ ! "$REPLY" = "0" ]] || { echo "Goodbye!" ; break; }
    echo "You picked $option which is option $REPLY"


# ---- END OF LOOP - DONE STATEMENT ----------------------------------------

done

# --------------------------------------------------------------------------

exit

# For comparison with original select builtin:
select option in "${WORDS[@]}"; do

    [[ ! "$REPLY" = "0" ]] || { echo "Goodbye!" ; break; }
    echo "You picked $option which is option $REPLY"

done