Update fp.sh

* error handling extended
* awk matches $0 now instead of $NF
- Attempting to match apps that do not put name in last field.
* $app moved into script due to incorrect error handling 
* grammer corrections

fp.sh

@@ -1,16 +1,20 @@
 #!/bin/sh -e
-#AUTHOR: David Lopez Jr. /* git(hub|lab).com/dlopezjr */
-#PURPOSE: Frontend wrapper for $(flatpak run)
+#PURPOSE: Wrapper for $(flatpak run)
 
-#VARIABLE(S)
-app=$(flatpak list --app | cut -f2 | awk -F. -v app="$1" '(tolower($NF) ~ tolower(app))')
-
-#FUNCTION(S)
 ##check if flatpak is installed and accesible to $PATH
-command -v flatpak >/dev/null 2>&1 || printf "Flatpak package was not found.\n";
+command -v flatpak >/dev/null 2>&1 || { printf "Flatpak package was not found.\n" && exit 1; };
+
+##check if any flatpak packages are installed
+test "$(flatpak list --all | head -c1 | wc -c)" -eq "0" && printf "No Flatpak packages are installed.\n" && exit 1;
+
+##check if an app name was entered
+test "$#" -eq "0" && printf "Enter an app to fp.\n\$ fp <app>\n\nINSTALLED APPS:\n$(flatpak list --all)\n" && exit 1; 
+
+##store reverse dns name for package
+app=$(flatpak list --app | cut -f2 | awk -F. -v app="$1" '(tolower($0) ~ tolower(app))')
 
-##check if no arguements were enetered by user 
-test "$#" -eq "0" && printf "Enter an app to fp.\n\$ fp <app>\n\nINSTALLED APPS\n$app\n" && exit 1; 
+##check if entered app name is valid
+test -z "$app" && printf "Entered app name is invalid.\n" && exit 1;
 
 ##remove app name from "$@" array
 shift 1;