[PATCH] Skip identical lines in hexdump

[Christian Franke <Christian.Franke@t-online.de>]

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This skips identical lines in hexdump output, like 'od' or 'xxd -a' also do.

Christian

PS: I would suggest to change hexdump 'buf' parameter from 'char *' to 
'const void *' to avoid unnecessary casts.


2009-01-30  Christian Franke  <franke@computer.org>

	* lib/hexdump.c (hexdump): Print at most 3 lines if data is identical.



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diff --git a/lib/hexdump.c b/lib/hexdump.c
index 9b79f45..7689edf 100644
--- a/lib/hexdump.c
+++ b/lib/hexdump.c
@@ -61,6 +61,22 @@ hexdump (unsigned long bse, char *buf, int len)
 
       grub_printf ("%s\n", line);
 
+      /* Print only first and last line of more than 3 lines are identical.  */
+      if (len >= 4 * 16
+	  && ! grub_memcmp (buf, buf + 1 * 16, 16)
+	  && ! grub_memcmp (buf, buf + 2 * 16, 16)
+	  && ! grub_memcmp (buf, buf + 3 * 16, 16))
+	{
+	  grub_printf ("*\n");
+	  do
+	    {
+	      bse += 16;
+	      buf += 16;
+	      len -= 16;
+	    }
+	  while (len >= 3 * 16 && ! grub_memcmp (buf, buf + 2 * 16, 16));
+	}
+
       bse += 16;
       buf += 16;
       len -= cnt;