diff --git a/lib/zip_file_get_offset.c b/lib/zip_file_get_offset.c
new file mode 100644
index 0000000..2d25c3d
--- /dev/null
+++ b/lib/zip_file_get_offset.c
@@ -0,0 +1,78 @@
+/*
+  $NiH: zip_file_get_offset.c,v 1.1.2.2 2004/04/06 20:27:22 dillo Exp $
+
+  zip_file_get_offset.c -- get offset of file data in archive.
+  Copyright (C) 1999, 2003, 2004 Dieter Baron and Thomas Klausner
+
+  This file is part of libzip, a library to manipulate ZIP archives.
+  The authors can be contacted at <nih@giga.or.at>
+
+  Redistribution and use in source and binary forms, with or without
+  modification, are permitted provided that the following conditions
+  are met:
+  1. Redistributions of source code must retain the above copyright
+     notice, this list of conditions and the following disclaimer.
+  2. Redistributions in binary form must reproduce the above copyright
+     notice, this list of conditions and the following disclaimer in
+     the documentation and/or other materials provided with the
+     distribution.
+  3. The names of the authors may not be used to endorse or promote
+     products derived from this software without specific prior
+     written permission.
+ 
+  THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS
+  OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+  ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
+  DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
+  GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
+  IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+  OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
+  IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include "zip.h"
+#include "zipint.h"
+
+
+
+/* _zip_file_get_offset(za, ze):
+   Returns the offset of the file data for entry ze.
+
+   On error, fills in za->error and returns 0.
+*/
+
+unsigned int
+_zip_file_get_offset(struct zip *za, int idx)
+{
+    struct zip_dirent de;
+    unsigned int offset;
+
+    offset = za->cdir->entry[idx].offset;
+
+    if (fseek(za->zp, offset, SEEK_SET) != 0) {
+	_zip_error_set(&za->error, ZERR_SEEK, errno);
+	return 0;
+    }
+
+    if (_zip_dirent_read(&de, za->zp, NULL, 0, 1, &za->error) != 0)
+	return 0;
+
+    offset += LENTRYSIZE + de.filename_len + de.extrafield_len;
+
+    _zip_dirent_finalize(&de);
+
+    return offset;
+}