Improve UI detection (fixes #16)

ufetch-linux

@@ -10,10 +10,21 @@ os='Linux'	# I'd just like to interject for a moment...
 kernel="$(uname -sr)"
 uptime="$(uptime | awk -F, '{sub(".*up ",x,$1);print $1}' | sed -e 's/^[ \t]*//')"
 packages='unknown'
-shell="$(basename "$SHELL")"
+shell="$(basename "${SHELL}")"
 
 ## UI DETECTION
 
+parse_rcs() {
+	for f in "${@}"; do
+		wm="$(tail -n 1 "${f}" 2> /dev/null | cut -d ' ' -f 2)"
+		[ -n "${wm}" ] && echo "${wm}" && return
+	done
+}
+
+rcwm="$(parse_rcs "${HOME}/.xinitrc" "${HOME}/.xsession")"
+
+ui='unknown'
+uitype='UI'
 if [ -n "${DE}" ]; then
 	ui="${DE}"
 	uitype='DE'
@@ -26,17 +37,14 @@ elif [ -n "${XDG_CURRENT_DESKTOP}" ]; then
 elif [ -n "${DESKTOP_SESSION}" ]; then
 	ui="${DESKTOP_SESSION}"
 	uitype='DE'
-elif [ -f "${HOME}/.xinitrc" ]; then
-	ui="$(tail -n 1 "${HOME}/.xinitrc" | cut -d ' ' -f 2)"
+elif [ -n "${rcwm}" ]; then
+	ui="${rcwm}"
 	uitype='WM'
-elif [ -f "${HOME}/.xsession" ]; then
-	ui="$(tail -n 1 "${HOME}/.xsession" | cut -d ' ' -f 2)"
-	uitype='WM'
-else
-	ui='unknown'
-	uitype='UI'
+elif [ -n "${XDG_SESSION_TYPE}" ]; then
+	ui="${XDG_SESSION_TYPE}"
 fi
-ui="$(basename ${ui})"
+
+ui="$(basename "${ui}")"
 
 ## DEFINE COLORS