--- a/src/luan/lib/Utils.java	Mon May 26 05:39:54 2014 +0000
+++ b/src/luan/lib/Utils.java	Thu May 29 09:26:44 2014 +0000
@@ -2,9 +2,17 @@
 
 import java.io.File;
 import java.io.FileReader;
+import java.io.FileWriter;
 import java.io.InputStreamReader;
 import java.io.Reader;
+import java.io.Writer;
 import java.io.IOException;
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.InputStream;
+import java.io.OutputStream;
 import java.net.URL;
 import luan.LuanState;
 import luan.LuanException;
@@ -14,6 +22,8 @@
 public final class Utils {
 	private Utils() {}  // never
 
+	private static final int bufSize = 8192;
+
 	public static void checkNotNull(LuanState luan,Object v,String expected) throws LuanException {
 		if( v == null )
 			throw luan.JAVA.exception("bad argument #1 ("+expected+" expected, got nil)");
@@ -22,7 +32,7 @@
 	public static String readAll(Reader in)
 		throws IOException
 	{
-		char[] a = new char[8192];
+		char[] a = new char[bufSize];
 		StringBuilder buf = new StringBuilder();
 		int n;
 		while( (n=in.read(a)) != -1 ) {
@@ -49,4 +59,59 @@
 		return s;
 	}
 
+	public static void copyAll(InputStream in,OutputStream out)
+		throws IOException
+	{
+		byte[] a = new byte[bufSize];
+		int n;
+		while( (n=in.read(a)) != -1 ) {
+			out.write(a,0,n);
+		}
+	}
+
+	public static byte[] readAll(File file)
+		throws IOException
+	{
+		int len = (int)file.length();
+		ByteArrayOutputStream out = new ByteArrayOutputStream(len) {
+			public byte[] toByteArray() {
+				return buf;
+			}
+		};
+		FileInputStream in = new FileInputStream(file);
+		copyAll(in,out);
+		in.close();
+		return out.toByteArray();
+	}
+
+	public static void write(File file,String s)
+		throws IOException
+	{
+		Writer out = new FileWriter(file);
+		out.write(s);
+		out.close();
+	}
+
+	public static void writeAll(byte[] a,OutputStream out)
+		throws IOException
+	{
+		copyAll(new ByteArrayInputStream(a),out);
+	}
+
+	public static void writeAll(File file,byte[] a)
+		throws IOException
+	{
+		FileOutputStream fos = new FileOutputStream(file);
+		writeAll(a,fos);
+		fos.close();
+	}
+
+	public static byte[] readAll(InputStream in)
+		throws IOException
+	{
+		ByteArrayOutputStream out = new ByteArrayOutputStream();
+		copyAll(in,out);
+		return out.toByteArray();
+	}
+
 }