feature: Add helloName function to greet with a name

src/main.rs

@@ -1,11 +1,13 @@
 extern crate libc;
 
 use libc::{ c_char, c_int, c_void, size_t };
-use std::ffi::CStr;
+use std::ffi::{ CStr, CString };
 use std::ptr;
 
-extern {
+#[link(name = "p4pillondebuglib")]
+extern "C" {
     fn hello() -> *const c_char;
+    fn helloName(name: *const c_char) -> *const c_char;
     fn helloPtr(result: *mut c_char);
     fn helloPtrPtr(result: *mut *mut c_char, size: *mut size_t);
     fn helloVoidPtrPtr(result: *mut *mut c_void, size: *mut size_t);
@@ -22,6 +24,15 @@ fn main() {
         println!("{} from C", r_str);
     }
 
+    let name = CString::new("John").expect("CString::new failed");
+    unsafe {
+        let c_str = helloName(name.as_ptr());
+        let r_str = CStr::from_ptr(c_str).to_str().expect("Conversion failed");
+        println!("{} from C with name", r_str);
+
+        libc::free(c_str as *mut c_void);
+    }
+
     let mut buffer: [c_char; 50] = [0; 50];
     unsafe {
         helloPtr(buffer.as_mut_ptr());

src/p4pillondebuglib.c

@@ -7,6 +7,14 @@ char* hello() {
     return "Hello, World!";
 }
 
+char* helloName(const char *name) {
+    char *result = (char *)malloc(strlen(name) + 9);
+    if (result) {
+        sprintf(result, "Hello, %s!", name);
+    }
+    return result;
+}
+
 void helloPtr(char *result) {
     sprintf(result, "Hello, World!");
 }

src/p4pillondebuglib.h

@@ -4,6 +4,7 @@
 #include <stddef.h>
 
 char* hello();
+char* helloName(const char *name);
 void helloPtr(char *result);
 void helloPtrPtr(char **result, size_t *size);
 void helloVoidPtrPtr(void **result, size_t *size);