functions

#!/bin/bash
# modified from archlinux/mkinitcpio/functions

parseopts() {
    local opt= optarg= i= shortopts=$1
    local -a longopts=() unused_argv=()

    shift
    while [[ $1 && $1 != '--' ]]; do
        longopts+=("$1")
        shift
    done
    shift

    longoptmatch() {
        local o longmatch=()
        for o in "${longopts[@]}"; do
            if [[ ${o%:} = "$1" ]]; then
                longmatch=("$o")
                break
            fi
            [[ ${o%:} = "$1"* ]] && longmatch+=("$o")
        done

        case ${#longmatch[*]} in
            1)
                # success, override with opt and return arg req (0 == none, 1 == required)
                opt=${longmatch%:}
                if [[ $longmatch = *: ]]; then
                    return 1
                else
                    return 0
                fi ;;
            0)
                # fail, no match found
                return 255 ;;
            *)
                # fail, ambiguous match
                printf "%s: option '%s' is ambiguous; possibilities:%s\n" "${0##*/}" \
                    "--$1" "$(printf " '%s'" "${longmatch[@]%:}")"
                return 254 ;;
        esac
    }

    while (( $# )); do
        case $1 in
            --) # explicit end of options
                shift
                break
                ;;
            -[!-]*) # short option
                for (( i = 1; i < ${#1}; i++ )); do
                    opt=${1:i:1}

                    # option doesn't exist
                    if [[ $shortopts != *$opt* ]]; then
                        printf "%s: invalid option -- '%s'\n" "${0##*/}" "$opt"
                        OPTRET=(--)
                        return 1
                    fi

                    OPTRET+=("-$opt")
                    # option requires optarg
                    if [[ $shortopts = *$opt:* ]]; then
                        # if we're not at the end of the option chunk, the rest is the optarg
                        if (( i < ${#1} - 1 )); then
                            OPTRET+=("${1:i+1}")
                            break
                        # if we're at the end, grab the the next positional, if it exists
                        elif (( i == ${#1} - 1 )) && [[ $2 ]]; then
                            OPTRET+=("$2")
                            shift
                            break
                        # parse failure
                        else
                            printf "%s: option '%s' requires an argument\n" "${0##*/}" "-$opt"
                            OPTRET=(--)
                            return 1
                        fi
                    fi
                done
                ;;
            --?*=*|--?*) # long option
                IFS='=' read -r opt optarg <<< "${1#--}"
                longoptmatch "$opt"
                case $? in
                    0)
                        if [[ $optarg ]]; then
                            printf "%s: option '--%s' doesn't allow an argument\n" "${0##*/}" "$opt"
                            OPTRET=(--)
                            return 1
                        else
                            OPTRET+=("--$opt")
                        fi
                        ;;
                    1)
                        # --longopt=optarg
                        if [[ $optarg ]]; then
                            OPTRET+=("--$opt" "$optarg")
                        # --longopt optarg
                        elif [[ $2 ]]; then
                            OPTRET+=("--$opt" "$2" )
                            shift
                        else
                            printf "%s: option '--%s' requires an argument\n" "${0##*/}" "$opt"
                            OPTRET=(--)
                            return 1
                        fi
                        ;;
                    254)
                        # ambiguous option -- error was reported for us by longoptmatch()
                        OPTRET=(--)
                        return 1
                        ;;
                    255)
                        # parse failure
                        printf "%s: unrecognized option '%s'\n" "${0##*/}" "--$opt"
                        OPTRET=(--)
                        return 1
                        ;;
                esac
                ;;
            *) # non-option arg encountered, add it as a parameter
                unused_argv+=("$1")
                ;;
        esac
        shift
    done

    # add end-of-opt terminator and any leftover positional parameters
    OPTRET+=('--' "${unused_argv[@]}" "$@")
    unset longoptmatch

    return 0
}

msg() {
    local mesg=$1; shift
    printf "$_color_green==>$_color_none $_color_bold$mesg$_color_none\n" "$@" >&1
}

msg2() {
    local mesg=$1; shift
    printf "  $_color_blue->$_color_none $_color_bold$mesg$_color_none\n" "$@" >&1
}

warning() {
    local mesg=$1; shift
    printf "$_color_yellow==> WARNING:$_color_none $_color_bold$mesg$_color_none\n" "$@" >&2
}

error() {
    local mesg=$1; shift
    printf "$_color_red==> ERROR:$_color_none $_color_bold$mesg$_color_none\n" "$@" >&2
    return 1
}

die() {
    error "$@"
    exit 1
}

map() {
    local r=0
    for _ in "${@:2}"; do
        "$1" "$_" || (( $# > 255 ? r=1 : ++r ))
    done
    return $r
}

try_enable_color() {
    local colors

    if ! colors=$(tput colors 2>/dev/null); then
        warning "Failed to enable color. Check your TERM environment variable"
        return
    fi

    if (( colors > 0 )) && tput setaf 0 &>/dev/null; then
        _color_none=$(tput sgr0)
        _color_bold=$(tput bold)
        _color_blue=$_color_bold$(tput setaf 4)
        _color_green=$_color_bold$(tput setaf 2)
        _color_red=$_color_bold$(tput setaf 1)
        _color_yellow=$_color_bold$(tput setaf 3)
    fi
}

# vim: set ft=sh ts=4 sw=4 et: