add new function io.ReadAll

R=gri
DELTA=14  (6 added, 4 deleted, 4 changed)
OCL=30072
CL=30074

src/lib/io/utils.go

@@ -11,17 +11,19 @@ import (
 	"os";
 )
 
+// ReadAll reads from r until an error or EOF and returns the data it read.
+func ReadAll(r Reader) ([]byte, os.Error) {
+	var buf ByteBuffer;
+	n, err := io.Copy(r, &buf);
+	return buf.Data(), err;
+}
 
-// ReadFile reads the file named by filename and returns
-// its contents if successful.
-//
+// ReadFile reads the file named by filename and returns the contents.
 func ReadFile(filename string) ([]byte, os.Error) {
 	f, err := os.Open(filename, os.O_RDONLY, 0);
 	if err != nil {
 		return nil, err;
 	}
-	var b io.ByteBuffer;
-	_, err := io.Copy(f, &b);
-	f.Close();
-	return b.Data(), err;
+	defer f.Close();
+	return ReadAll(f);
 }