diff --git a/.gitignore b/.gitignore
index 78fd378..34e4a67 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,3 @@
 **/*.sw*
+**/*.gch
+**/a.out
diff --git a/c.d/helloworld.c b/c.d/helloworld.c
new file mode 100644
index 0000000..0a8f557
--- /dev/null
+++ b/c.d/helloworld.c
@@ -0,0 +1,5 @@
+#include "helloworld.h"
+
+void main() {
+   printf("hello world\n");
+}
diff --git a/c.d/helloworld.h b/c.d/helloworld.h
new file mode 100644
index 0000000..53c5fdf
--- /dev/null
+++ b/c.d/helloworld.h
@@ -0,0 +1 @@
+#include <stdio.h>
diff --git a/c.d/run.sh b/c.d/run.sh
new file mode 100644
index 0000000..80e39ba
--- /dev/null
+++ b/c.d/run.sh
@@ -0,0 +1,8 @@
+#! /bin/bash
+
+set -e
+set -o pipefail
+set -u
+
+gcc ./*.{h,c}
+./a.out