diff --git a/ch2-cgo/ch2-01-hello-cgo.md b/ch2-cgo/ch2-01-hello-cgo.md
index 6ef6597..0da467a 100644
--- a/ch2-cgo/ch2-01-hello-cgo.md
+++ b/ch2-cgo/ch2-01-hello-cgo.md
@@ -86,7 +86,7 @@ package main
 void cgoPuts(char* s);
 
 static void SayHello(const char* s) {
-	cgoPuts(s);
+	cgoPuts((char*)(s));
 }
 */
 import "C"
diff --git a/examples/ch2-01/hello-01/main.go b/examples/ch2-01/hello-01/main.go
new file mode 100644
index 0000000..fbfdecd
--- /dev/null
+++ b/examples/ch2-01/hello-01/main.go
@@ -0,0 +1,8 @@
+package main
+
+//#include <stdio.h>
+import "C"
+
+func main() {
+	C.puts(C.CString("Hello, World\n"))
+}
diff --git a/examples/ch2-01/hello-02/main.go b/examples/ch2-01/hello-02/main.go
new file mode 100644
index 0000000..3c2cd40
--- /dev/null
+++ b/examples/ch2-01/hello-02/main.go
@@ -0,0 +1,14 @@
+package main
+
+/*
+#include <stdio.h>
+
+static void SayHello(const char* s) {
+	puts(s);
+}
+*/
+import "C"
+
+func main() {
+	C.SayHello(C.CString("Hello, World\n"))
+}
diff --git a/examples/ch2-01/hello-03/hello.c b/examples/ch2-01/hello-03/hello.c
new file mode 100644
index 0000000..095f0ba
--- /dev/null
+++ b/examples/ch2-01/hello-03/hello.c
@@ -0,0 +1,5 @@
+#include <stdio.h>
+
+void SayHello(const char* s) {
+	puts(s);
+}
diff --git a/examples/ch2-01/hello-03/main.go b/examples/ch2-01/hello-03/main.go
new file mode 100644
index 0000000..876e944
--- /dev/null
+++ b/examples/ch2-01/hello-03/main.go
@@ -0,0 +1,8 @@
+package main
+
+//void SayHello(const char* s);
+import "C"
+
+func main() {
+	C.SayHello(C.CString("Hello, World\n"))
+}
diff --git a/examples/ch2-01/hello-04/main.go b/examples/ch2-01/hello-04/main.go
new file mode 100644
index 0000000..b59fcc0
--- /dev/null
+++ b/examples/ch2-01/hello-04/main.go
@@ -0,0 +1,22 @@
+package main
+
+/*
+#include <stdio.h>
+
+void cgoPuts(char* s);
+
+static void SayHello(const char* s) {
+	cgoPuts((char*)(s));
+}
+*/
+import "C"
+import "fmt"
+
+func main() {
+	C.SayHello(C.CString("Hello, World\n"))
+}
+
+//export cgoPuts
+func cgoPuts(s *C.char) {
+	fmt.Print(C.GoString(s))
+}
diff --git a/examples/ch2-01/hello-05/main.go b/examples/ch2-01/hello-05/main.go
new file mode 100644
index 0000000..95ff047
--- /dev/null
+++ b/examples/ch2-01/hello-05/main.go
@@ -0,0 +1,17 @@
+package main
+
+//void SayHello(char* s);
+import "C"
+
+import (
+	"fmt"
+)
+
+func main() {
+	C.SayHello(C.CString("Hello, World\n"))
+}
+
+//export SayHello
+func SayHello(s *C.char) {
+	fmt.Print(C.GoString(s))
+}