say

#!/usr/bin/env bash

read -r -d '' VERSION <<'HERE'
say version 1.2
Copyright (c) 2020 Jeff Ober
License MIT: https://mit-license.org/

Written by Jeff Ober
HERE

read -r -d '' USAGE <<'HERE'

    say [options] [tokens+]

Options:

    --help    | -h      display this help text
    --version | -v      display version information
                -n      do not output a newline
                -e      enable string escapes
                -E      disable string escapes (default)

Displays a colorized line of text.

Colors are controlled with the following command tokens:

    Clear
    Reset
    Bold
    Dim
    Italic
    Underline
    Blink
    Invert
    Hidden
    Default

    Black
    Blue
    Cyan
    Green
    Magenta
    Red
    White
    Yellow

    Bold_Black
    Bold_Blue
    Bold_Cyan
    Bold_Green
    Bold_Magenta
    Bold_Red
    Bold_White
    Bold_Yellow

    On_Black
    On_Blue
    On_Cyan
    On_Green
    On_Magenta
    On_Red
    On_White
    On_Yellow

    On_Bold_Black
    On_Bold_Blue
    On_Bold_Cyan
    On_Bold_Green
    On_Bold_Magenta
    On_Bold_Red
    On_Bold_White
    On_Bold_Yellow

    # 256 colors
    Ansi_XXX
    On_Ansi_XXX
HERE


#-------------------------------------------------------------------------------
# Determine if the script is being loaded as a library (via the 'source'
# command) or directly.
#-------------------------------------------------------------------------------
AS_LIB=0

# Try to execute a `return` statement, but do it in a sub-shell and catch the
# results. If this script isn't sourced, that will raise an error.
$(return >/dev/null 2>&1)

# What exit code did that give?
if [ "$?" -eq "0" ]; then
    AS_LIB=1
fi

#-------------------------------------------------------------------------------
# Set defaults for control variables
#-------------------------------------------------------------------------------
: ${SAY_NEWLINE:=1}
: ${SAY_ESCAPES:=0}

ECHO_ARGS='-n'

#-------------------------------------------------------------------------------
# Main loop
#-------------------------------------------------------------------------------
function say:main {
    #---------------------------------------------------------------------------
    # Process each token in the list
    #---------------------------------------------------------------------------
    for tok in "$@"; do
        case $tok in
            Clear)           echo -n -e "\e[0m";;
            Reset)           echo -n -e "\e[0m";;
            Bold)            echo -n -e "\e[1m";;
            Dim)             echo -n -e "\e[2m";;
            Italic)          echo -n -e "\e[3m";;
            Underline)       echo -n -e "\e[4m";;
            Blink)           echo -n -e "\e[5m";;
            Invert)          echo -n -e "\e[7m";;
            Hidden)          echo -n -e "\e[8m";;
            Default)         echo -n -e "\e[39m";;

            Black)           echo -n -e "\e[30m";;
            Blue)            echo -n -e "\e[34m";;
            Cyan)            echo -n -e "\e[36m";;
            Green)           echo -n -e "\e[32m";;
            Magenta)         echo -n -e "\e[35m";;
            Red)             echo -n -e "\e[31m";;
            White)           echo -n -e "\e[37m";;
            Yellow)          echo -n -e "\e[33m";;

            Bold_Black)      echo -n -e "\e[90m";;
            Bold_Blue)       echo -n -e "\e[94m";;
            Bold_Cyan)       echo -n -e "\e[96m";;
            Bold_Green)      echo -n -e "\e[92m";;
            Bold_Magenta)    echo -n -e "\e[95m";;
            Bold_Red)        echo -n -e "\e[91m";;
            Bold_White)      echo -n -e "\e[97m";;
            Bold_Yellow)     echo -n -e "\e[93m";;

            On_Black)        echo -n -e "\e[40m";;
            On_Blue)         echo -n -e "\e[44m";;
            On_Cyan)         echo -n -e "\e[46m";;
            On_Green)        echo -n -e "\e[42m";;
            On_Magenta)      echo -n -e "\e[45m";;
            On_Red)          echo -n -e "\e[41m";;
            On_White)        echo -n -e "\e[47m";;
            On_Yellow)       echo -n -e "\e[43m";;

            On_Bold_Black)   echo -n -e "\e[100m";;
            On_Bold_Blue)    echo -n -e "\e[104m";;
            On_Bold_Cyan)    echo -n -e "\e[106m";;
            On_Bold_Green)   echo -n -e "\e[102m";;
            On_Bold_Magenta) echo -n -e "\e[105m";;
            On_Bold_Red)     echo -n -e "\e[101m";;
            On_Bold_White)   echo -n -e "\e[107m";;
            On_Bold_Yellow)  echo -n -e "\e[103m";;

            Ansi_*)          echo -n -e "\e[38;5;${tok/Ansi_/}m";;
            On_Ansi_*)       echo -n -e "\e[48;5;${tok/On_Ansi_/}m";;

            *)               echo $ECHO_ARGS "$tok";;
        esac
    done

    echo -e -n "\e[0m"

    if [ $SAY_NEWLINE -eq 1 ]; then
        echo
    fi
}

#-------------------------------------------------------------------------------
# If being sourced as a library, then define 'say' as a function. Otherwise,
# run say:main directly.
#-------------------------------------------------------------------------------
if [ $AS_LIB -eq 1 ]; then
    function say {
        say:main "$@"
    }
else
    #---------------------------------------------------------------------------
    # Scan for arguments to say
    #---------------------------------------------------------------------------
    for arg in "$@"; do
        case $arg in
            --help|-h)
                echo "$USAGE"
                echo
                exit 0
                ;;

            --version|-v)
                echo "$VERSION"
                echo
                exit 0
                ;;

            -n)
                SAY_NEWLINE=0
                shift
                ;;

            -e)
                SAY_ESCAPES=1
                shift
                ;;

            -E)
                SAY_ESCAPES=0
                shift
                ;;

            *)
                break;
                ;;
        esac
    done

    if [ $SAY_ESCAPES -eq 1 ];
        then ECHO_ARGS+=" -e";
    fi

    say:main "$@"
fi