generate-prompt-colors

#!/usr/bin/env bash
# generate-prompt-colors-file
#
#  generate-prompt-colors-files -hnv [OUTPUTFILE]
#
# run this script to create "prompt-colors.sh", which contains
# standard prompt color definitions, and a "reset_prompt_colors"
# function to unset them all.
#
# Copywrite 2006-2022 Alan K. Stebbens <aks@stebbens.org>

PROG="${0##*/}"
THIS_DIR="${0%/*}"

# this is the filename we create
PROMPT_COLOR_FILENAME='prompt-colors.sh'

export PATH=$PATH:$HOME/lib
source sh-utils.sh
source list-utils.sh
source talk-utils.sh
source run-utils.sh

usage() {
  cat 1>&2 <<EOF
usage: $PROG [options] [OUTDIR]

Create a file that contains a standard set of colornames suitable
for the bash prompt.  along with a function called
'reset_color_names' that unsets all the color names.

The output file, always named '$PROMPT_COLOR_FILNAME', will be
written to $OUTDIR, which defaults to '.'

If the output file already exists, it will be renamed with ".old"
as the suffix.

Use the '-n' option to see how the file would be created, but
not actually created.

Options:
   -h       show this help
   -n       don't make any changes; just show the commands
   -v       be verbose
EOF
  exit
}

# generate_prompt_color_names
#
# Write a set of color name assignments to STDOUT.
#
# Creates two functions: define_color_names, and reset_color_names.

generate_prompt_color_names() {

  ColorNames=( Black Red Green Yellow Blue Magenta Cyan White )
  FgColors=(    30   31   32    33     34   35      36   37  )
  BgColors=(    40   41   42    43     44   45      46   47  )

  local color_name_list=()

  local AttrNorm=0
  local AttrBright=1
  local AttrDim=2
  local AttrUnder=4
  local AttrBlink=5
  local AttrRev=7
  local AttrHide=8

  # define "BoldCOLOR", "BrightCOLOR", and "DimCOLOR" names

  # map_color_names ATTRNAME ATTRVALUE
  #
  # Defines three names for every color, attribute combintaion:
  #    {ATTRNAME}{COLORNAME}
  #    {ATTRNAME}{COLORNAME}Fg
  #    {ATTRNAME}{COLORNAME}Bg
  #
  # Example: BoldRed, BoldRedFg, BoldRedBg

  map_color_names() {
    local x=0
    local attrname="$1"
    local attrcode=$2
    while (( x < 8 )) ; do
      local colorname=${ColorNames[x]}
      local fgcolorcode=${FgColors[x]}
      local bgcolorcode=${BgColors[x]}
      longcolorname="${attrname}${colorname}"
      assign_color_name $longcolorname     $attrcode $fgcolorcode
      assign_color_name ${longcolorname}Fg $attrcode $fgcolorcode
      assign_color_name ${longcolorname}Bg $attrcode $bgcolorcode
      (( x++ ))
    done
  }

  # prompt_color_string [ N | N M ]
  prompt_color_string() {
    local cv
    if (( $# > 1 )); then
      cv="${1};${2}"
    else
      cv="${1}"
    fi
    echo "\$'\033[${cv}m'"
  }

  # def_color NAME ATTRCODE COLORCODE
  assign_color_name() {
    local color_name="$1"
    local code="`prompt_color_string $2 $3`"
    local def="$color_name=$code"
    votalk "+ $def"
    echo "  $def"
    add_list color_name_list $color_name
  }

  echo "#"
  echo "# define_color_names -- invoke to define all of the prompt color names"
  echo "#"
  echo 'define_color_names() {'

  #ResetColor="`prompt_color_string 0`"         # Text reset

  map_color_names Bold   $AttrBright
  map_color_names Bright $AttrBright
  map_color_names Dim    $AttrDim
  map_color_names ''     $AttrNorm

  assign_color_name IntenseBlack 0 90
  assign_color_name ResetColor   0 0

  echo "}"

  # now create the reset function

  echo ""
  echo "# reset_color_names -- invoke to unset all the color names"
  echo ""
  echo "reset_color_names() {"
  map_list color_name_list "echo \"  unset \$item\"" "$CHAR_NL"
  echo "}"
}

# create_prompt_color_file OUTDIR
#
# if OUTDIR is missing, use '.' (current directory) by default
# the output filename is always 'prompt-colors.sh'
#
# The following variables should be defined before invoking this function:
#
# $PROMPT_COLOR_FILENAME, $PROG, $USER, $ARGSTR

create_prompt_color_file() {
  local outdir="${1:-.}"

  if [[ ! -d "$outdir" ]]; then
    error "The directory '$outdir' doesn't exist!"
  fi

  local outfile="$outdir/$PROMPT_COLOR_FILENAME"

  if [[ -f "$outfile" ]]; then
    oldfile="$outfile.old"
    nqtalk "Renaming previous file to $oldfile"
    run "mv \"$outfile\" \"$oldfile\""
  fi

  # redirect STDOUT to the output file
  exec 3>&1       # save a copy of current STDOUT
  if (( ! norun )) ; then
    exec 1>"$outfile"
  else
    exec 1>&2
  fi
  cat <<HEAD
# $PROMPT_COLOR_FILENAME
#
# Please do not modify this file directly.
#
# This file was automatically generated by $USER at `date`
# using $PROG $ARGSTR

HEAD
  generate_prompt_color_names
  cat <<TAIL

if [[ -z "\$IntenseBlack" || -z "\$ResetColor" || -z "\$Blue" ]]; then
  define_color_names
fi

# end of $PROMPT_COLOR_FILENAME
TAIL
  exec 1>&-       # close STDOUT
  exec 1>&3       # recover original STDOUT
  if (( ! norun )) ; then
    lines=`wc -l <"$outfile"`
    talkf "%d lines written to %s\n" $lines "$outfile"
  else
    talk "Nothing written"
  fi
}

# the main app processing

ARGSTR="${ARGV[@]}"

while getopts 'hnv' opt ; do
  case "$opt" in
    h) usage ;;
    n) norun=1 ;;
    v) verbose=1 ;;
  esac
done
shift $(( OPTIND - 1 ))

outdir="$1{:-.}"      # output directory or '.' by default

create_prompt_color_file $1

exit

# end of prompt-colors.sh
# vim: set ai sw=2