colors.shell

#!/bin/env bash
#
# Copyright (c) Roberto A. Foglietta, 2023
#
# Authors:
#  Roberto A. Foglietta <roberto.foglietta@gmail.com>
#
# SPDX-License-Identifier: MIT
#
#set -x && resetx="set +x" # RAF: source, paired with set +x at the end of file
#set -Eeuo pipefail  # RAF: this is only for test with every restriction possible
                     #      bash -c "source colors.shell && source colors.shell"
set -u               # RAF: only for devel, comment in main

###############################################################################
#
# Composition rule for printing colored text on the console
#
# echo -e "${mode}${textcolor}${text}${reset}" 
#
# to add a background color this is the rule with basic codes
#
# echo -e "${mode}${background}${textcolor}${text}${reset}" 
#
# or using the auto-generated codes like in these example
#
# echo -e "${BLRED} Hello world in light red! ${CRST}"
#
# auto-generated codes are also available in lower-case format
#
# echo -ne "${dgrnowht} Ciao in dark green over white. ${crst}\n"
#
###############################################################################

if [ ${GFRELOAD:-0} -eq 0 ]; then
    echo "${BASH_SOURCE[0]##*/} not reloaded, try again with 'GFRELOAD=1 source'"
    return 1
fi
type colors_codes_generation 2>&1 | grep -q "is a function" && return 0

trap 'echo -e "\n${ERROR:-ERROR}: in '${BASH_SOURCE[0]##*/}\
' at line ${LINENO} occured, try again with set -x\n" >&2' ERR

###############################################################################

# RAF: restricted shell cannot redirect to file but it is fine
#      to redirect to a open file descriptor towards /dev/null
#      So, also exec could fail but in gitshell &3 is just open
if [ ${GITSHLVL:-0} -lt 1 ]; then
    exec 3>/dev/null || return $?
fi

echo "Loading ${BASH_SOURCE[0]##*/} into current bash enviroment"

###############################################################################

# The echo needs -e to print colored output
function echo() {
    command echo -e "$@"
}
export -f echo

# The export of the basic variables statically defined

optx="x" # uncomment to export color codes

# To bound variable because set -u requires it

optx=${optx:-}
test "${optx}" != "x" && optx=""

###############################################################################

if true; then

# Displaying Modes

declare -r${optx} NRM="\033[0"     || :   # normal
declare -r${optx} BLD="\033[1"     || :   # bold
declare -r${optx} DRK="\033[2"     || :   # dark
declare -r${optx} ITL="\033[3"     || :   # italic
declare -r${optx} UDL="\033[4"     || :   # underline
declare -r${optx} FLS="\033[5"     || :   # blinking -> flashing
declare -r${optx} RVS="\033[7"     || :   # reverse
declare -r${optx} HDN="\033[8"     || :   # hidden
declare -r${optx} SRK="\033[9"     || :   # strikethrough

# Regular Colors

declare -r${optx} BLK=";30m"       || :   # black
declare -r${optx} RED=";31m"       || :   # red
declare -r${optx} GRN=";32m"       || :   # green
declare -r${optx} YLW=";33m"       || :   # yellow
declare -r${optx} BLU=";34m"       || :   # blue
declare -r${optx} PRL=";35m"       || :   # purple
declare -r${optx} CYN=";36m"       || :   # cyan
declare -r${optx} WHT=";37m"       || :   # white

# Backgound Colors

declare -r${optx} OBLK=";40"       || :   # black
declare -r${optx} ORED=";41"       || :   # red
declare -r${optx} OGRN=";42"       || :   # green
declare -r${optx} OYLW=";43"       || :   # yellow
declare -r${optx} OBLU=";44"       || :   # blue
declare -r${optx} OPRL=";45"       || :   # purple
declare -r${optx} OCYN=";46"       || :   # cyan
declare -r${optx} OWHT=";47"       || :   # white

# High Intensity Colors

declare -r${optx} LBLK=";90m"      || :   # light_black
declare -r${optx} LRED=";91m"      || :   # light_red
declare -r${optx} LGRN=";92m"      || :   # light_green
declare -r${optx} LYLW=";93m"      || :   # light_yellow
declare -r${optx} LBLU=";94m"      || :   # light_blue
declare -r${optx} LPRL=";95m"      || :   # light_purple
declare -r${optx} LCYN=";96m"      || :   # light_cyan
declare -r${optx} LWHT=";97m"      || :   # ligth_white

# Color Reset

declare -r${optx} CRST="\033[0;0m" || :   # reset

fi 2>&3

###############################################################################

# List of Colors and Displaying Modes

COLORS="BLK RED GRN YLW BLU PRL CYN WHT"
DMODES="NRM BLD DRK ITL UDL FLS RVS SRK"

# This declares the basic variables in lower case and exports them optx=x

if true; then
    for i in $COLORS $DMODES CRST; do
        eval declare -r${optx} '${i,,}'=\"\$$i\" || :
    done
    for i in L O; do
        for j in $COLORS; do
            eval declare -r${optx} '${i,,}${j,,}'=\"\${$i$j}\" ||:
        done
    done
fi 2>&3

# This declares the basic variables as read-onnly and exports them if optx=x

if false; then
    declare -r${optx} ${COLORS} ${DMODES} CRST crst || :
    for j in ${COLORS}; do
        declare -r${optx} O$j L$j || :
    done
    unset j
fi 2>&3

# Auto-generating function for colors codes

function colors_codes_generation() {
    local i j l p s b g k
    for i in ${DMODES}; do
        for j in ${COLORS}; do
            for b in '' ${COLORS}; do
                for l in '' L; do
                    p="${i:0:1}$l"
                    k="O$b"
                    k=${k%O}
                    echo -n "declare -r${optx} $p$j$k='"
                    g=${k:-''}
                    g=${g/O/\$O}
                    eval "printf '%s%s%s' \$$i $g \$$l$j"
                    g="$k + "
                    s=${b:-\\t}
                    s=${s//[A-Z]/}
                    echo "' || :  $s\t# $i + ${g# + }$l$j"
                 done
             done
        done
    done
}

# Auto-generation of colors codes

if true; then
    eval "$(colors_codes_generation)"
    eval "$(colors_codes_generation | tr '[A-Z]' '[a-z]')"
else
    tmp=$(mktemp -p "${TMPDIR:-}")
    colors_codes_generation >$tmp
    colors_codes_generation | tr '[A-Z]' '[a-z]' >>$tmp
    source $tmp 2>&3
    rm -f $tmp
fi 2>&3

###############################################################################

# Relevant keyword coloured

if true; then

declare -r${optx} WARNING="${BLYLW}WARNING${CRST}"  || :
declare -r${optx} ERROR="${BLRED}ERROR${CRST}"      || :
declare -r${optx} DONE="${BLGRN}DONE${CRST}"        || :
declare -r${optx} OK="${BLGRN}OK${CRST}"            || :
declare -r${optx} KO="${BLRED}KO${CRST}"            || :
declare -r${optx} ON="${BLGRN}ON${CRST}"            || :
declare -r${optx} OFF="${BLRED}OFF${CRST}"          || :
declare -r${optx} ENTER="${BLWHT}ENTER${CRST}"      || :
declare -r${optx} USAGE="${BLPRL}USAGE${CRST}"      || :
declare -r${optx} NOTICE="${BLCYN}NOTICE${CRST}"    || :
declare -r${optx} PLAY="${BLGRN}PLAY${CRST}"        || :
declare -r${optx} PAUSE="${BLYLW}PAUSE${CRST}"      || :
declare -r${optx} STOP="${BLRED}STOP${CRST}"        || :

fi 2>&3

###############################################################################
${resetx:-}
trap -- ERR
true