@@ -252,10 +252,38 @@
 
 	if (fd == -1 || eos || (ret = write(fd, buf, size)) < size)
 		@throw [OFWriteFailedException newWithClass: isa
 						       size: size];
 
+	return ret;
+}
+
+- _seekToOffset: (off_t)offset
+{
+	if (lseek(fd, offset, SEEK_SET) == -1)
+		@throw [OFSeekFailedException newWithClass: isa];
+
+	return self;
+}
+
+- (size_t)_seekForwardWithOffset: (off_t)offset
+{
+	off_t ret;
+
+	if ((ret = lseek(fd, offset, SEEK_CUR)) == -1)
+		@throw [OFSeekFailedException newWithClass: isa];
+
+	return ret;
+}
+
+- (size_t)_seekToOffsetRelativeToEnd: (off_t)offset
+{
+	off_t ret;
+
+	if ((ret = lseek(fd, offset, SEEK_END)) == -1)
+		@throw [OFSeekFailedException newWithClass: isa];
+
 	return ret;
 }
 
 - close
 {