bin/colortest256

   1 #!/bin/bash
   2 # https://tldp.org/HOWTO/Bash-Prompt-HOWTO/x329.html
   3 # https://gist.github.com/XVilka/8346728#gistcomment-3528771
   4
   5 T='::'   # The test text
   6
   7 function echo_block() {
   8     local fs=$1
   9     local bs=$2
  10     echo "   01234567"
  11     for (( f = 0; f < 8; f++ )); do
  12         echo -en " ${f} "
  13         for (( b = 0; b < 8; b++ )); do
  14             echo -en "\033[38;5;$((fs+f))m\033[48;5;$((bs+b))m$T\033[0m";
  15         done
  16         echo
  17     done
  18 }
  19
  20 function print_colors() {
  21     local c
  22     for (( c = $1; c < $1 + $2; c++)); do
  23         echo -en "\033[48;5;${c}m$T\033[0m"
  24     done
  25     echo
  26 }
  27 function colors() {
  28     print_colors 0 8
  29     print_colors 8 8
  30     for (( c = 16; c < 256 - 24; c += 36 )); do
  31         print_colors $c 36
  32     done
  33     print_colors $((256 - 24)) 24
  34 }
  35
  36 function true_colors() {
  37     awk -v term_cols="${width:-$(tput cols || echo 80)}" 'BEGIN{
  38         s="/\\";
  39         for (colnum = 0; colnum<term_cols; colnum++) {
  40             r = 255-(colnum*255/term_cols);
  41             g = (colnum*510/term_cols);
  42             b = (colnum*255/term_cols);
  43             if (g>255) g = 510-g;
  44             printf "\033[48;2;%d;%d;%dm", r,g,b;
  45             printf "\033[38;2;%d;%d;%dm", 255-r,255-g,255-b;
  46             printf "%s\033[0m", substr(s,colnum%2+1,1);
  47         }
  48         printf "\n";
  49     }'
  50 }
  51
  52 colors
  53 true_colors