eos-bash-shared/eos-color

#!/bin/bash

EosColor() {
    local color="$1"    # one of the foreground color strings below, or a reserved word below
    local std="$2"      # optional; stdout (=default) or stderr or 2
    local progname=${0##*/}

    case "$color" in
        -h | --help)   Help 0 ;;
    esac

    source "/etc/$progname.conf"

    case "$color" in
        "" | reset)    color="$RESET" ;;
        error | fail)  color="$RED" ;;
        warning)       color="$YELLOW" ;;
        info)          color="$GREEN" ;;
        tip | ok)      color="$CYAN" ;;
    esac
    case "$std" in
        stderr | 2) echo -n "$color" >&2 ;;
        *)          echo -n "$color" ;;
    esac
}

Help() {
    local -r progname=${0##*/}
    cat <<EOF
Usage:      $progname [Options] Color-def [Target-def]
Options:    -h, --help             This help. Optional.
Color-def:  Color variables defined in /etc/$progname.conf. Required.
            Special values:
                error, fail        For errors messages (red).
                warning            For warning messages (yellow).
                info               For info messages (green).
                tip, ok            For tips and OK messages (cyan).
                "", reset          Back to "normal" colors.
Target-def: Sets the file descriptor (fd) for the output. Optional.
            Values:
                2, stderr          Output to fd 2.
                Any other value    Output to fd 1.
Examples:
    eos-color error stderr         Sets the color of future outputs to "error" (red).
                                   Output goes to fd 2.
    eos-color \$RED 2               Same as above, using a variable from /etc/$progname.conf.
    eos-color tip                  Sets the color for future tips (for fd 1).
    eos-color reset 2              Sets future outputs to "normal" colors (for fd 2).
    eos-color                      Sets future outputs to "normal" colors (for fd 1).
EOF
    [ "$1" ] && exit $1
}

EosColor "$@"