New module 'ftell'.

[gnulib.git] / lib / ftell.c

diff --git a/lib/ftell.c b/lib/ftell.c
new file mode 100644 (file)
index 0000000..796e687
--- /dev/null
+++ b/lib/ftell.c
@@ -0,0 +1,39 @@
+/* An ftell() function that works around platform bugs.
+   Copyright (C) 2007 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include <stdio.h>
+
+#include <errno.h>
+/* Get off_t.  */
+#include <unistd.h>
+
+long
+ftell (FILE *fp)
+{
+  /* Use the replacement ftello function with all its workarounds.  */
+  off_t offset = ftello (fp);
+  if (offset == (long)offset)
+    return (long)offset;
+  else
+    {
+      errno = EOVERFLOW;
+      return -1;
+    }
+}