1 files changed, 54 insertions, 0 deletions
diff --git a/stdio/ftell.c b/stdio/ftell.c
new file mode 100644
index 0000000000..d27eaf7598
--- /dev/null
+++ b/stdio/ftell.c
@@ -0,0 +1,54 @@
+/* Copyright (C) 1991, 1992, 1994 Free Software Foundation, Inc.
+This file is part of the GNU C Library.
+
+The GNU C Library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Library General Public License as
+published by the Free Software Foundation; either version 2 of the
+License, or (at your option) any later version.
+
+The GNU C Library 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
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB.  If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA.  */
+
+#include <ansidecl.h>
+#include <errno.h>
+#include <stdio.h>
+
+/* Return the offset in bytes from the beginning
+   of the file of the file position of STREAM.  */
+long int
+DEFUN(ftell, (stream), FILE *stream)
+{
+  long int pos;
+
+  if (!__validfp (stream))
+    {
+      errno = EINVAL;
+      return -1L;
+    }
+
+  if (__stdio_check_offset (stream) == EOF)
+    return -1L;
+
+  /* Start with the file position associated with the beginning
+     of our buffer.  */
+  pos = stream->__target;
+
+  if (stream->__pushed_back)
+    /* ungetc was just called, so our real buffer pointer is squirreled
+       away in STREAM->__pushback_bufp, not in STREAM->__bufp as normal.
+       Calling ungetc is supposed to decrement the file position.  ANSI
+       says the file position is unspecified if you ungetc when the
+       position is zero; -1 seems as good as anything to me.  */
+    pos += stream->__pushback_bufp - stream->__buffer - 1;
+  else
+    pos += stream->__bufp - stream->__buffer;
+
+  return pos;
+}