shellfu/include/charmenu.sh

ffoo import core


FFOO_CHARMENU_FILE="${FFOO_CHARMENU_FILE:-}"


charmenu() {
    #
    # Present "1-char-menu" (but actually N-char) or its parts
    #
    # Read file in FFOO_CHARMENU_FILE or given as -f parameter,
    # and do what either `full` menu, `prompt`, or just terse
    # list of `items` (like "y,n,q,?").
    #
    # Format of menu file is one item per line, where item is
    # delimited from its description by single colon. Leading
    # and trailing spaces and spaces around the colon are
    # stripped.
    #
    # You can use printf symbols like `%s` in menu and then
    # call `charmenu full arg1 arg2...` to have your arguments
    # expanded in the full menu.
    #
    # Similarly, you can specify single `%s` in the prompt
    # parameter like `charmenu -p "choose from %s" and it will
    # be replaced by list of items read from menu file,
    # delimited either by comma or character provided as `-d`
    # parameter.
    #
    # `has` checks if given string is a valid menu item.
    #
    local mfile="$FFOO_CHARMENU_FILE"
    local prompt="What to do next [%s]? "
    local delim=","
    local cmd cases
    while true; do case $1 in
        -d|--delimiter)         delim="$2"; shift 2     ;;
        -f|--file)              mfile="$2"; shift 2     ;;
        -i|--ignore-case)       cases="-i";  shift      ;;
        -p|--prompt)            prompt="$2"; shift 2    ;;
        full|items|prompt|has)  cmd=$1; shift; break    ;;
        *)  usage_is "full [PRINTF_ARG...]" \
                     "items [DELIM]"        \
                     "prompt [PRINTF_FMT]"  \
                     "has ITEM"                         ;;
    esac done

    local menu="$(cat "$mfile")"
    local alist="$(echo "$menu" | cut -d: -f1 | sed -re 's/^ +//; s/ +$//')"
    debug -v alist

    case $cmd in
        full)   # print the full menu, with any printf notation expanded
            printf "$menu\n" "$@"
            ;;
        items)  # print just the list of actions
            paste -sd"$delim" <<<"$alist"
            ;;
        prompt) # print prompt for user
            printf "$prompt" "$(charmenu items)"
            ;;
        has)    # check if response is valid ("on the menu")
            local res="$1"
            test -n "$res" || return 1      # "" is not valid
            grep $cases -e "^$res$" <<<"$alist"
            return $?
            ;;
    esac
}