(fseeko): Define a stub if ! HAVE_FSEEKO.

(skip): Use fseeko if available.  Don't use lseek; it causes
the stdio stream to become out of sync with respect to the
underyling file descriptor.
From Paul Eggert.

diff --git a/src/od.c b/src/od.c
index 9170107..72e33ca 100644 (file)
--- a/src/od.c
+++ b/src/od.c
@@ -109,6 +109,11 @@ typedef double LONG_DOUBLE;
 # define LDBL_DIG DBL_DIG
 #endif
 
+#if !HAVE_FSEEKO
+# undef fseeko
+# define fseeko(Stream, Offset, Whence) (-1)
+#endif
+
 enum size_spec
   {
     NO_SIZE,
@@ -1039,13 +1044,10 @@ skip (off_t n_skip)
            }
          else
            {
-             /* fseek may work on some streams for which lseek doesn't.
-                But fseek's offset argument is restricted to the range
-                of type `long'.  So if N_SKIP is too large or if fseek
-                fails, try lseek.  */
-             if ((n_skip <= LONG_MAX
-                  && fseek (in_stream, (long) n_skip, SEEK_SET) == 0)
-                 || lseek (fileno (in_stream), n_skip, SEEK_SET) >= 0)
+             /* Try fseeko if available, fseek otherwise.  */
+             if (fseeko (in_stream, n_skip, SEEK_SET) == 0
+                 || (n_skip <= LONG_MAX
+                     && fseek (in_stream, (long) n_skip, SEEK_SET) == 0))
                {
                  n_skip = 0;
                  break;