moved file resolution code to a shared library

Makefile

@@ -7,10 +7,10 @@
 
 .POSIX:
 
-PREFIX=/usr/local/bin
-CFLAGS=-O3 -s -Wl,-z,noseparate-code,-z,nosectionheader -flto
+PREFIX=/usr/local
+CFLAGS=-O3 -s -Wl,-z,noseparate-code,-z,nosectionheader -flto -Lbuild -lyac
 
-build: build_dir cat false true
+build: build_dir lib cat false tail true
 
 clean: build_dir
 	rm -rf build/
@@ -21,12 +21,20 @@ cat: build_dir
 false: build_dir
 	cc $(CFLAGS) -o build/false src/false.c
 
+tail: build_dir
+	cc $(CFLAGS) -o build/tail src/tail.c
+
 true: build_dir
 	cc $(CFLAGS) -o build/true src/true.c
 
+lib:
+	cc -c -fPIC $(CFLAGS) -o build/yac.o src/yac.c
+	cc $(CFLAGS) -shared -o build/libyac.so build/yac.o
+
 build_dir:
 	mkdir -p build
 
 install: build
 	mkdir -p $(PREFIX)
-	cp -f build/* $(PREFIX)/
+	cp -f build/*.so $(PREFIX)/lib/
+	cp -f build/* $(PREFIX)/bin/