jrocha-io · May 14, 2023 17:35 · May 26, 2017
diff --git a/16-color-table.sh b/16-color-table.sh
@@ -0,0 +1,18 @@
+#!/bin/bash
+#
+# This file echoes a bunch of color codes to the terminal to demonstrate
+# what's available. Each line is the color code of one forground color,
+# out of 17 (default + 16 escapes), followed by a test use of that color
+# on all nine background colors (default + 8 escapes).
+#
+T='gYw'   # The test text
+echo -e "\n                 40m     41m     42m     43m     44m     45m     46m     47m";
+for FGs in '    m' '   1m' '  30m' '1;30m' '  31m' '1;31m' '  32m' '1;32m' '  33m' '1;33m' '  34m' '1;34m' '  35m' '1;35m' '  36m' '1;36m' '  37m' '1;37m';
+  do FG=${FGs// /}
+  echo -en " $FGs \033[$FG  $T  "
+  for BG in 40m 41m 42m 43m 44m 45m 46m 47m;
+    do echo -en "$EINS \033[$FG\033[$BG  $T \033[0m\033[$BG \033[0m";
+  done
+  echo;
+done
+echo
diff --git a/24-bit-color.sh b/24-bit-color.sh
@@ -0,0 +1,100 @@
+#!/bin/bash
+# This file was originally taken from iterm2 https://github.com/gnachman/iTerm2/blob/master/tests/24-bit-color.sh
+#
+#   This file echoes a bunch of 24-bit color codes
+#   to the terminal to demonstrate its functionality.
+#   The foreground escape sequence is ^[38;2;<r>;<g>;<b>m
+#   The background escape sequence is ^[48;2;<r>;<g>;<b>m
+#   <r> <g> <b> range from 0 to 255 inclusive.
+#   The escape sequence ^[0m returns output to default
+
+setBackgroundColor()
+{
+    #printf '\x1bPtmux;\x1b\x1b[48;2;%s;%s;%sm' $1 $2 $3
+    printf '\x1b[48;2;%s;%s;%sm' $1 $2 $3
+}
+
+resetOutput()
+{
+    echo -en "\x1b[0m\n"
+}
+
+# Gives a color $1/255 % along HSV
+# Who knows what happens when $1 is outside 0-255
+# Echoes "$red $green $blue" where
+# $red $green and $blue are integers
+# ranging between 0 and 255 inclusive
+rainbowColor()
+{ 
+    let h=$1/43
+    let f=$1-43*$h
+    let t=$f*255/43
+    let q=255-t
+
+    if [ $h -eq 0 ]
+    then
+        echo "255 $t 0"
+    elif [ $h -eq 1 ]
+    then
+        echo "$q 255 0"
+    elif [ $h -eq 2 ]
+    then
+        echo "0 255 $t"
+    elif [ $h -eq 3 ]
+    then
+        echo "0 $q 255"
+    elif [ $h -eq 4 ]
+    then
+        echo "$t 0 255"
+    elif [ $h -eq 5 ]
+    then
+        echo "255 0 $q"
+    else
+        # execution should never reach here
+        echo "0 0 0"
+    fi
+}
+
+for i in `seq 0 127`; do
+    setBackgroundColor $i 0 0
+    echo -en " "
+done
+resetOutput
+for i in `seq 255 -1 128`; do
+    setBackgroundColor $i 0 0
+    echo -en " "
+done
+resetOutput
+
+for i in `seq 0 127`; do
+    setBackgroundColor 0 $i 0
+    echo -n " "
+done
+resetOutput
+for i in `seq 255 -1 128`; do
+    setBackgroundColor 0 $i 0
+    echo -n " "
+done
+resetOutput
+
+for i in `seq 0 127`; do
+    setBackgroundColor 0 0 $i
+    echo -n " "
+done
+resetOutput
+for i in `seq 255 -1 128`; do
+    setBackgroundColor 0 0 $i
+    echo -n " "
+done
+resetOutput
+
+for i in `seq 0 127`; do
+    setBackgroundColor `rainbowColor $i`
+    echo -n " "
+done
+resetOutput
+for i in `seq 255 -1 128`; do
+    setBackgroundColor `rainbowColor $i`
+    echo -n " "
+done
+resetOutput
diff --git a/256-color-table.sh b/256-color-table.sh
@@ -0,0 +1,27 @@
+#!/bin/bash
+#
+# generates an 8 bit color table (256 colors) for
+# reference purposes, using the \033[48;5;${val}m
+# ANSI CSI+SGR (see "ANSI Code" on Wikipedia)
+#
+echo -en "\n   +  "
+for i in {0..35}; do
+  printf "%2b " $i
+done
+
+printf "\n\n %3b  " 0
+for i in {0..15}; do
+  echo -en "\033[48;5;${i}m  \033[m "
+done
+
+#for i in 16 52 88 124 160 196 232; do
+for i in {0..6}; do
+  let "i = i*36 +16"
+  printf "\n\n %3b  " $i
+  for j in {0..35}; do
+    let "val = i+j"
+    echo -en "\033[48;5;${val}m  \033[m "
+  done
+done
+
+echo -e "\n"