rewrite in rust

build.rs

@@ -0,0 +1,20 @@
+use std::env;
+use std::path::PathBuf;
+
+fn main()
+{
+    let builder = bindgen::builder();
+
+    let bindings = builder.header("/usr/include/expat.h")
+                          .generate()
+                          .expect("The libexpat headers must be installed");
+
+    let out_dir: PathBuf = env::var("OUT_DIR")
+                               .expect("Environment variable $OUT_DIR must be defined")
+                               .into();
+    let out_file = out_dir.join("expat.rs");
+
+    println!("cargo::rustc-link-lib=expat");
+
+    bindings.write_to_file(out_file).expect("Writing failure");
+}