# start fbterm automatically in /dev/tty*

if (( ${+commands[fbterm]} )); then
	if [[ "$TTY" = /dev/tty* ]] ; then
		fbterm
		exit
	fi
fi

# start fbterm automatically in /dev/tty*

if [[ $(tty|grep -o '/dev/tty') = /dev/tty ]] ; then
	fbterm
	exit
fi

--- 
+++ 
@@ -1,6 +1,8 @@
 # start fbterm automatically in /dev/tty*
 
-if [[ $(tty|grep -o '/dev/tty') = /dev/tty ]] ; then
-	fbterm
-	exit
+if (( ${+commands[fbterm]} )); then
+	if [[ "$TTY" = /dev/tty* ]] ; then
+		fbterm
+		exit
+	fi
 fi
Check if fbterm is installed and use $TTY variable
