let user select lab submission part

Author: Cody Cutler

GNUmakefile

@@ -222,7 +222,9 @@ git-handin: handin-check
 WEBSUB = https://ccutler.scripts.mit.edu/6.828/handin.py
 
 handin: tarball-pref myapi.key
-	@curl -f -F file=@lab$(LAB)-handin.tar.gz -F key=\<myapi.key $(WEBSUB)/upload \
+	@SUF=$(LAB); \
+	test -f .suf && SUF=`cat .suf`; \
+	curl -f -F file=@lab$$SUF-handin.tar.gz -F key=\<myapi.key $(WEBSUB)/upload \
 	    > /dev/null || { \
 		echo ; \
 		echo Submit seems to have failed.; \
@@ -254,7 +256,21 @@ tarball: handin-check
 	git archive --format=tar HEAD | gzip > lab$(LAB)-handin.tar.gz
 
 tarball-pref: handin-check
-	git archive --prefix=lab$(LAB)/ --format=tar HEAD | gzip > lab$(LAB)-handin.tar.gz
+	@SUF=$(LAB); \
+	if test $(LAB) -eq 3 -o $(LAB) -eq 4; then \
+		read -p "Which part would you like to submit? [a, b, c (lab 4 only)]" p; \
+		if test "$$p" != a -a "$$p" != b; then \
+			if test ! $(LAB) -eq 4 -o ! "$$p" = c; then \
+				echo "Bad part \"$$p\""; \
+				exit 1; \
+			fi; \
+		fi; \
+		SUF="$(LAB)$$p"; \
+		echo $$SUF > .suf; \
+	else \
+		rm -f .suf; \
+	fi; \
+	git archive --prefix=lab$(LAB)/ --format=tar HEAD | gzip > lab$$SUF-handin.tar.gz
 
 myapi.key:
 	@echo Get an API key for yourself by visiting $(WEBSUB)