1 files changed, 119 insertions, 0 deletions
diff --git a/grub-core/commands/cmp.c b/grub-core/commands/cmp.c
new file mode 100644
index 0000000..e9c3b25
--- /dev/null
+++ b/grub-core/commands/cmp.c
@@ -0,0 +1,119 @@
+/* cmd.c - command to cmp an operating system */
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2003,2005,2006,2007,2009  Free Software Foundation, Inc.
+ *
+ *  GRUB 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 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB 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 GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <grub/dl.h>
+#include <grub/misc.h>
+#include <grub/file.h>
+#include <grub/mm.h>
+#include <grub/command.h>
+#include <grub/i18n.h>
+
+GRUB_MOD_LICENSE ("GPLv3+");
+
+#define BUFFER_SIZE 512
+
+static grub_err_t
+grub_cmd_cmp (grub_command_t cmd __attribute__ ((unused)),
+	      int argc, char **args)
+{
+  grub_ssize_t rd1, rd2;
+  grub_off_t pos;
+  grub_file_t file1 = 0;
+  grub_file_t file2 = 0;
+  char *buf1 = 0;
+  char *buf2 = 0;
+
+  if (argc != 2)
+    return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("two arguments expected"));
+
+  grub_printf_ (N_("Compare file `%s' with `%s':\n"), args[0],
+		args[1]);
+
+  file1 = grub_file_open (args[0], GRUB_FILE_TYPE_CMP);
+  file2 = grub_file_open (args[1], GRUB_FILE_TYPE_CMP);
+  if (! file1 || ! file2)
+    goto cleanup;
+
+  if (grub_file_size (file1) != grub_file_size (file2))
+    grub_printf_ (N_("Files differ in size: %llu [%s], %llu [%s]\n"),
+		  (unsigned long long) grub_file_size (file1), args[0],
+		  (unsigned long long) grub_file_size (file2), args[1]);
+  else
+    {
+      pos = 0;
+
+      buf1 = grub_malloc (BUFFER_SIZE);
+      buf2 = grub_malloc (BUFFER_SIZE);
+
+      if (! buf1 || ! buf2)
+        goto cleanup;
+
+      do
+	{
+	  int i;
+
+	  rd1 = grub_file_read (file1, buf1, BUFFER_SIZE);
+	  rd2 = grub_file_read (file2, buf2, BUFFER_SIZE);
+
+	  if (rd1 != rd2)
+	    goto cleanup;
+
+	  for (i = 0; i < rd2; i++)
+	    {
+	      if (buf1[i] != buf2[i])
+		{
+		  grub_printf_ (N_("Files differ at the offset %llu: 0x%x [%s], 0x%x [%s]\n"),
+				(unsigned long long) (i + pos), buf1[i],
+				args[0], buf2[i], args[1]);
+		  goto cleanup;
+		}
+	    }
+	  pos += BUFFER_SIZE;
+
+	}
+      while (rd2);
+
+      /* TRANSLATORS: it's always exactly 2 files.  */
+      grub_printf_ (N_("The files are identical.\n"));
+    }
+
+cleanup:
+
+  grub_free (buf1);
+  grub_free (buf2);
+  if (file1)
+    grub_file_close (file1);
+  if (file2)
+    grub_file_close (file2);
+
+  return grub_errno;
+}
+
+static grub_command_t cmd;
+
+GRUB_MOD_INIT(cmp)
+{
+  cmd = grub_register_command ("cmp", grub_cmd_cmp,
+			       N_("FILE1 FILE2"), N_("Compare two files."));
+}
+
+GRUB_MOD_FINI(cmp)
+{
+  grub_unregister_command (cmd);
+}