Tmux: indicator for prefix in statusbar

tmux/prefix_highlight.tmux

@@ -0,0 +1,49 @@
+#!/usr/bin/env bash
+
+set -e
+
+# Place holder for status left/right
+place_holder="\#{prefix_highlight}"
+
+# Possible configurations
+fg_color_config='@prefix_highlight_fg'
+bg_color_config='@prefix_highlight_bg'
+
+# Defaults
+default_fg='black'
+default_bg='yellow'
+
+tmux_option() {
+    local -r value=$(tmux show-option -gqv "$1")
+    local -r default="$2"
+
+    if [ ! -z "$value" ]; then
+        echo "$value"
+    else
+        echo "$default"
+    fi
+}
+
+highlight() {
+    local -r status="$1" prefix="$2" fg_color="$3" bg_color="$4"
+    local -r status_value=$(tmux_option "$status")
+    local -r highlight_on_prefix="#[fg=$fg_color,bg=$bg_color]#{?client_prefix, $prefix ,}#[fg=default,bg=default]"
+
+    tmux set-option -gq "$status" "${status_value/$place_holder/$highlight_on_prefix}"
+}
+
+main() {
+    local -r \
+        prefix=$(tmux_option prefix) \
+        fg_color=$(tmux_option "$fg_color_config" "$default_fg") \
+        bg_color=$(tmux_option "$bg_color_config" "$default_bg")
+
+    local -r short_prefix=$(
+        echo "$prefix" | tr "[:lower:]" "[:upper:]" | sed 's/C-/\^/'
+    )
+
+    highlight "status-right" "$short_prefix" "$fg_color" "$bg_color"
+    highlight "status-left" "$short_prefix" "$fg_color" "$bg_color"
+}
+
+main