Added Make install and fix to main

src/Makefile

@@ -29,6 +29,10 @@ cleantest:
 test: testfuncs
 	./testfuncs
 
+.PHONY: install
+install: cacmb
+	cp ./cacmb /usr/local/bin
+
 $(OBJECTS) : parameters.o
 atoms.o subroutines.o testfuncs.o box.o : functions.o
 main.o io.o $(MODES) $(OPTIONS) : elements.o 

src/main.f90

@@ -23,6 +23,7 @@ program main
     !Call initialization functions
     call lattice_init
     call box_init
+    end_mode_arg = 0
     
     ! Command line parsing
     arg_num = command_argument_count()
@@ -36,6 +37,10 @@ program main
         call call_mode(end_mode_arg, argument)
     end if
 
+    !Check to make sure a mode was called
+    if (end_mode_arg=0) then 
+        stop "Please run cacmb using an available mode"
+    end if
     !Now we loop through all of the arguments and check for passed options or for a filename to be written out
     arg_pos = end_mode_arg
     do while(.true.)