add example

example/bar.c

@@ -0,0 +1,4 @@
+#include "bar.h"
+#include <stdio.h>
+
+void bar() { printf("bai\n"); }

example/bar.h

@@ -0,0 +1,3 @@
+#ifndef B
+#define B
+#endif

example/cubefile

@@ -0,0 +1,24 @@
+rule all test
+
+OBJ = [test.o foo.o bar.o]
+
+rule test $OBJ [
+    echo " LD" $target
+    shell cc -o $target $sources
+]
+
+rule %.o %.c [
+    echo " CC" $target
+    shell cc -c -o $target $source
+]
+
+rule clean [] [
+    echo " CLEAN" $OBJ test
+    shell rm -f $OBJ test
+]
+
+// dependencies
+
+rule foo.o foo.h
+rule bar.o bar.h
+rule test.o [foo.h bar.h]

example/foo.c

@@ -0,0 +1,4 @@
+#include "foo.h"
+#include <stdio.h>
+
+void foo() { printf("hai\n"); }

example/foo.h

@@ -0,0 +1,3 @@
+#ifndef A
+#define A
+#endif

example/test.c

@@ -0,0 +1,13 @@
+#include "foo.h"
+#include "bar.h"
+#include <stdio.h>
+
+void foo();
+void bar();
+
+int main() {
+    foo();
+    bar();
+    printf("hello world\n");
+    return 0;
+}