Added check for username

Added iteration over WMs for single username call

root-notify-user

@@ -1,12 +1,33 @@
-#!/bin/sh
-# This script allows calling notify-send as root for it to appear on vt's desktop
-
-USERNAME="$1"
-shift
-
-UID=$(id -u "${USERNAME}")
-WM_PID=$(pgrep --exact --uid "${UID}" "i3")
-ENV_FILE="/proc/${WM_PID}/environ"
-DBUS_SESSION_BUS_ADDRESS=$(grep -z DBUS_SESSION_BUS_ADDRESS "${ENV_FILE}"|cut -d= -f2- | tr -d '\0')
-DISPLAY=$(grep -z DISPLAY "${ENV_FILE}"|cut -d= -f2- | tr -d '\0')
-sudo -u "${USERNAME}" DISPLAY="${DISPLAY}" DBUS_SESSION_BUS_ADDRESS="${DBUS_SESSION_BUS_ADDRESS}" notify-send "$@"
+#!/bin/bash
+# This script allows calling notify-send as root for it to appear on specific user's desktop
+# Kept separate from the other script because it has explicit first parameter handling.
+
+set -euo pipefail
+
+USERNAME=${1:-}
+
+if [ -z "${USERNAME}" ]; then
+    >&2 echo "No username passed. Exiting."
+    exit 1
+else
+    shift
+fi
+
+MY_UID=$(id -u "${USERNAME}") || exit 1
+
+readarray -t KNOWN_WMS < <(grep "^Exec" /usr/share/xsessions/* | sed 's/^.*Exec=//' | grep -v Xsession)
+
+if [ ${#KNOWN_WMS[@]} -eq 0 ]; then
+    >&2 echo "Could not locate any window managers in /usr/share/xsessions/. Exiting."
+    exit 1
+fi
+
+
+for WM in "${KNOWN_WMS[@]}"; do
+    WM_PID=$(pgrep --exact "${WM}" --uid "${MY_UID}") || continue
+    ENV_FILE="/proc/${WM_PID}/environ"
+    DBUS_SESSION_BUS_ADDRESS=$(grep -z DBUS_SESSION_BUS_ADDRESS "${ENV_FILE}"|cut -d= -f2- | tr -d '\0')
+    DISPLAY=$(grep -z DISPLAY "${ENV_FILE}"|cut -d= -f2- | tr -d '\0')
+    USERNAME=$(stat -c '%U' "${ENV_FILE}")
+    sudo -u "${USERNAME}" DISPLAY="${DISPLAY}" DBUS_SESSION_BUS_ADDRESS="${DBUS_SESSION_BUS_ADDRESS}" notify-send "$@"
+done