add a simple argv/argc test

Makefile

@@ -11,7 +11,7 @@ TARGETS=approximate-pi linked-list mandelbrot threads circular-buffer structs \
 				uiowa-threads-example uiowa-threads-my-example \
 				mtrace-test av-variance undefined-behaviour \
 				multibrot-openmp hello-openmp mandelbrot-openmp \
-				positional-format-strings unions
+				positional-format-strings unions argv
 EXTRAS=mandelbrot.bmp multibrot.png test-inline-assembly.s \
 				mtrace-test.trace mtrace-test.txt multibrot-openmp.png
 VERYEXTRAS=cppcheck.txt macros.txt tags

argv.c

@@ -0,0 +1,10 @@
+#include <stdio.h>
+
+int main(int argc, char* argv[]) {
+  for (int i = 0; i<argc; i++) {
+    printf("%d: %s\n", i, argv[i]);
+  }
+  if (argv[argc] == 0) {
+    printf("\nargv[argc] is a null pointer, as required by the standard!\n");
+  }
+}