Note: xterm color palette

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diff --git a/content/notes/show-xterm-colors.md b/content/notes/show-xterm-colors.md
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+---
+title: Display xterm color palette
+url: write-iso-usb.html
+date: 2023-05-25
+type: notes
+draft: false
+tags: [linux, xterm, palette]
+---
+
+- `bash xterm-palette.sh` - will show you number of max colors available
+- `bash xterm-palette.sh -v` - will create a list of all colors with codes
+
+![xterm color palette](/notes/xterm-palette.png)
+
+```sh
+#!/usr/bin/env bash
+# xterm-palette.sh
+
+trap 'tput sgr0' exit           # Clean up even if user hits ^C
+
+function setfg () {
+    printf '\e[38;5;%dm' $1
+}
+
+function setbg () {
+    printf '\e[48;5;%dm' $1
+}
+
+function showcolors() {
+    # Given an integer, display that many colors 
+    for ((i=0; i<$1; i++))
+    do
+        printf '%4d ' $i
+        setbg $i
+        tput el
+        tput sgr0
+        echo
+    done
+    tput sgr0 el
+}
+
+# First, test if terminal supports OSC 4 at all.
+printf '\e]4;%d;?\a' 0
+read -d $'\a' -s -t 0.1 </dev/tty
+if [ -z "$REPLY" ]
+then
+    # OSC 4 not supported, so we'll fall back to terminfo 
+    max=$(tput colors)
+else
+    # OSC 4 is supported, so use it for a binary search 
+    min=0
+    max=256
+    while [[ $((min+1)) -lt $max ]]
+    do
+        i=$(( (min+max)/2 ))
+        printf '\e]4;%d;?\a' $i
+        read -d $'\a' -s -t 0.1 </dev/tty
+        if [ -z "$REPLY" ]
+        then
+            max=$i
+        else
+            min=$i
+        fi
+    done
+fi
+
+
+# If -v is given, show all the colors
+case ${1-none} in
+    none)
+        echo $max
+        ;;
+    -v)
+        showcolors $max
+        ;;
+    *)
+        if [[ "$1" -gt 0 ]]; then
+            showcolors $1
+        else
+            echo $max
+        fi
+        ;;
+esac | less --raw-control-chars --QUIT-AT-EOF --no-init
+```
diff --git a/static/notes/xterm-palette.png b/static/notes/xterm-palette.png
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--- /dev/null
+++ b/static/notes/xterm-palette.png