Xterm color chart generator

color.lua

local  reset  =  '\027(B\027[m'


function  cellx  ( prefix_core, text )    -----------------------------  cellx
  io .write ( reset )
  io .write ( ('\27[%sm') : format ( prefix_core ) )
  io .write ( text )
  io .write ( reset )  end


function  color_chart_16  ()  --------------------------------  color_chart_16

  local function  color  ( n )
    if  n == 30  then   return  ('100;%s') : format ( n )  end
    if  n == 40  then   return  ('90;%s') : format ( n )  end
    if  n == 44  then   return  ('94;%s') : format ( n )  end
   return  ('30;%s') : format ( n )  end

  local function  row  ( a, b )
    io .write '    '
    for  n=b,b+7  do  cellx ( color(n), (' %03d ') : format ( n ) )  end
    io .write ( ('    %s  \n') : format ( a ) )  end

  print  ''
  print  '  \\e[Nm    N=30-37,40-47,90-97,100-107'
  row ( 'tput setaf 00-07',  30 )
  row ( 'tput setaf 08-15',  90 )
  row ( 'tput setab 00-07',  40 )
  row ( 'tput setab 08-15', 100 )  end


function  color_chart_256  ()    ----------------------------  color_chart_256

  local function  color  ( n )
    local  s  =  '38;5;%d;48;5;%d'
    if  n <=   0  then  return  s:format(238,n)  end
    if  n ==   4  then  return  s:format(12,n)  end
    if  n <=  15  then  return  s:format(0,n)  end
    if  n <=  21  then  return  s:format(238,n)  end
    if  n <= 231  then  return  s:format(0,n)  end
    if  n <= 244  then  return  s:format(n+8,n)  end
    if  n <= 255  then  return  s:format(n-8,n)  end  end

  local function  row  ( a, b, c, d, e, f, g, h, i )
    local function  row  ( j, a, b, c )
      io .write ( (' '):rep(j) )
      for  n = a, a+(b*((c or 1)))-1, (c or 1)  do
	cellx ( color(n), (' %03d ') : format ( n ) )
        end  end
    row ( a, b, c, d )
    if  e  then  row ( e, f, g, h )  end
    io .write ( i or '\n' )  end

  print ''
  print '  \\e[38;5;Nm    N=0-255    tput setaf N    ( set foreground )'
  print '  \\e[48;5;Nm    N=0-255    tput setab N    ( set background )'
  row ( 4,   0,  8 )
  row ( 4,   8,  8 )
  row ( 4, 232, 13 )
  row ( 4, 15, 1, 1, 0, 7, 1, 1, '' )
  row ( 0, 255, 9, -1 )
  for  n=16,33  do  row ( 4, n, 6, 36, 5, n+18, 6, 36 )  end  end


function  ps1  ()    ----------------------------------------------------  ps1
  print  ''
  print  '  in bash set PS1 as follows:'
  print  '    wrap non-printing characters in \\[ and \\]'
  print  '    set terminal title with \\e]0;your title here\\007'
  print  '      see  https://gist.github.com/lenormf/5c638b8c58b7460140cfa281d452f17e'
  print  '      see  https://serverfault.com/q/23978'
  print  '      see  https://en.wikipedia.org/wiki/ANSI_escape_code#SGR_parameters'
  end


function  style_chart  ()    ------------------------------------  style_chart

  local  names, seqs  =  {},  {}
  local  proc         =  io .popen 'infocmp -1'

  for  s  in  proc : lines()  do
    local  name, seq  =  s : match '^\t*(.-)=(.-),'
    if  name  then
      --  print ( name, seq )
      names [ name ]  =  seq
      seqs  [ seq  ]  =  name  end  end
  assert ( proc : close() )


  --  print ()
  for  n=0,74  do
    local  seq   =  ('\\E[%dm') : format ( n )
    local  name  =  seqs [ seq ]
    --  print ( n, seq, name )
    end


  local  function  stylex  ( seq, name, comment )
    local  s    =  '    %-11s  %-7s  %s%s%s'
    name        =  name     or  seqs [ seq ]  or  '-'
    comment     =  comment  or  name
    local  raw  =  seq : gsub ( '\\E', '\027' )
    print ( s : format ( seq, name, raw, comment, reset ) )
    end


  print ''
  print '  style chart'
  print '    code         tput     comment'


  --  stylex  'sgr0'
  --  stylex  ( nil, '\\E[0m', '"reset / normal"' )

  stylex  '\\E(B\\E[m'
  stylex  ( '\\E(B\\E[0m', 'srg 0' )

  stylex  ( '\\E(0', nil, 'altcharset' )

  stylex  ( '\\E[0m', nil, '"all attributes off"' )
  stylex  '\\E[1m'
  stylex  '\\E[2m'
  stylex  '\\E[3m'
  stylex  ( '\\E[4m', nil, '"underline"' )
  stylex  '\\E[5m'
  stylex  ( '\\E[6m', nil, '"rapid blink"' )
  stylex  ( '\\E[7m', 'rev',  'reverse' )
  stylex  ( '\\E[7m', 'smso', 'standout' )
  stylex  '\\E[8m'
  stylex  '\\E[9m'

--[[
  stylex  '\\E[10m'
  stylex  '\\E[11m'
  stylex  '\\E[12m'
  stylex  '\\E[13m'
  stylex  '\\E[14m'
  stylex  '\\E[15m'
  stylex  '\\E[16m'
  stylex  '\\E[17m'
  stylex  '\\E[18m'
  stylex  '\\E[19m'

  stylex  '\\E[20m'
  stylex  '\\E[21m'
  stylex  '\\E[22m'
  stylex  '\\E[23m'
  stylex  '\\E[24m'
  stylex  '\\E[25m'
  stylex  '\\E[26m'
  stylex  '\\E[27m'
  stylex  '\\E[28m'
  stylex  '\\E[29m'
--]]

  stylex  ( '\\E[39m', nil, '"default foreground color"' )
  stylex  ( '\\E[49m', nil, '"default background color"' )
  end


function  main  ()    --------------------------------------------------  main
  ps1()
  style_chart()
  color_chart_16()
  color_chart_256()
  end


main()

color.png

old-color-xterm.png

old-color-xterm.sh

#! /bin/sh


#  This script prints a chart of 256 xterm colors.
#  The script also prints tips for writing and editing escape sequences.
#  Parts of the script are hardcoded to generate xterm escape sequences.
#  Many common terminals may be compatible with these xterm sequences.
#  It should be straightfoward to adapt the script to work on any terminal.
#  The script runs in dash, bash, and possibly other shells.
#
#  Updated 20170119.


#  hint:  infocmp -1 | less
#  hint:  https://wiki.archlinux.org/index.php/Bash/Prompt_customization#Colors


infocmp_parse ()  {    # ---------------------------------------- infocmp_parse

  #  20170118  infocmp_parse is no longer used.

  for  line  in  $(  infocmp -1  );  do

    capability=${line%%=*}
    code=${line#*=}
    code=${code%,}

    case  "$capability"  in
      ('sgr0' )  sgr0="$code"   ;;
      ('smso' )  smso="$code"   ;;
      ('smul' )  smul="$code"   ;;
      ('rev'  )  rev="$code"    ;;
      ('blink')  blink="$code"  ;;
      ('dim'  )  dim="$code"    ;;
      ('bold' )  bold="$code"   ;;
      ('invis')  invis="$code"  ;;
      ('prot' )  prot="$code"   ;;
      ('smacs')  smacs="$code"  ;;
      esac

    done;  }


style_line ()  {  name="$1";  capability="$2"    # ----------------- style_line
  code=$(  tput  "$capability"  "$3"  )
  code_=$(  echo "$code"  |  sed  "s/$esc/\\\\E/g";  )
  printf  '    %-14s  %-12s  %s\n'  "$name"  "$code_"  "$code$name$sgr0";  }


style_guide ()  (    # -------------------------------------------- style_guide

  esc=$(   printf  '\033'  )
  sgr0=$(  tput    sgr0    )

  printf  '  style codes\n'
  style_line    'none (sgr0)'     sgr0
  style_line    'none (sgr 0)'    sgr 0
  style_line    standout          smso
  style_line    underline         smul
  style_line    reverse           rev
  style_line    blink             blink
  style_line    dim               dim
  style_line    bold              bold
  style_line    invisible         invis
  style_line    protect           prot
  style_line    altcharset        smacs  )


color_guide ()  (  capname="$1";  description="$2";    # ---------- color_guide

  esc=$(   printf  '\033'  )

  f ()  {  tput  "$capname"  "$1"  |  sed  "s/$esc/\\\\E/g";  }

  printf  '  %s\n'  "$description"
  printf  '    0-7        0  %-16s    7  %s\n'  "$( f  0 )"  "$( f   7 )"
  printf  '    8-15       8  %-16s   15  %s\n'  "$( f  8 )"  "$( f  15 )"
  printf  '    16-255    16  %-16s  255  %s\n'  "$( f 16 )"  "$( f 255 )"  )


usage_guide ()  (    # -------------------------------------------- usage_guide

  esc=$(   printf  '\033'  )
  sgr0=$(  tput    sgr0    )

  f ()  {  description="$1"  code="$2"
    code_=$(  echo "$code"  |  sed  "s/$esc/\\\\E/g"  )
    printf '    %-25s  %s\n'  "$code_"  "$code$description$sgr0";  }

  printf  '  example codes created dynamically via the tput command\n'
  f  'foreground color 196'          "$( tput setaf 196 )"
  f  'foreground color 226, bold'    "$( tput setaf 226  &&  tput bold )"
  f  'background color 20'           "$( tput setab 20 )"

  echo
  printf  '  stitac, manually created example codes that work on xterm\n'

  f  'foreground color 226, none'    "$( printf '\33[0;38;5;226m' )"
  f  'foreground color 226, bold'    "$( printf '\33[1;38;5;226m' )"

  f  'foreground and background combined'  \
       "$( printf '\33[0;38;5;226;48;5;20m' )"

  f  'foreground and background combined'  \
       "$( printf '\33[1;38;5;226;48;5;20m' )"

  printf  '    Note:  In xterm, the 16-255 color codes '
  printf  'work for all colors 0-255.\n'  )


range ()  {  a="$1";  b="$2";  step="$3"    # --------------------------- range
  while  [  "$a"  -le  "$b"  ];  do
    echo "$a";  a="$(($a+$step))";  done;  }


color_cell ()  {    # ---------------------------------------------- color_cell
  if  [ "$1" -ge 232 ]  &&  [ "$1" -le 243 ];  then
    printf  "\33[38;5;$(($1+8))m"
  elif  [ "$1" -ge 244 ]  &&  [ "$1" -le 255 ]; then
    printf  "\33[38;5;$(($1-8))m"
  else
    case "$1" in
      (0|4|16|17|18|19|20|21)    printf  "\33[38;5;238m"  ;;
      (*)                        printf  "\33[38;5;0m"    ;;
      esac;  fi
  printf  '\33[48;5;%dm %03d '  "$c"  "$c";  }


color_row ()  {    # ------------------------------------------------ color_row
          #  usage:  color_row  prefix  a  b  step  suffix
  printf "$1"
  for  c  in  $( range "$2" "$3" "$4" );  do  color_cell  "$c";  done
  printf "$sgr0$5";  }


color_chart ()  (    # -------------------------------------------- color_chart

  printf  '  color chart\n'

  sgr0=$(  tput  sgr0        )

  color_row  '    '    0    7  1  '\n'
  color_row  '    '    8   15  1  '\n'
  color_row  '    '  232  243  1  '\n'
  color_row  '    '  244  255  1  '\n'

  for n in $( range 0 17 1 );  do
    color_row  '    '   $((16+n))  $((196+n))  36
    color_row  '     '  $((34+n))  $((214+n))  36  '\n';  done  )


main ()  (    # ---------------------------------------------------------- main
  echo;  style_guide
  echo;  color_guide  setaf  'foreground color codes'
  echo;  color_guide  setab  'background color codes'
  echo;  usage_guide
  echo;  color_chart
  )


main