[PATCH] add clear screen command

[Carlos Roberto do Nascimento Costa]

Hello,

This simple patch will add a new command to clear the terminal screen. Very
useful on the command-line.

Best Regards,

-- 
Carlos Roberto do Nascimento Costa
e-mail: address@hidden
IBM - Linux Technology Center Brasil

Index: conf/common.rmk
===================================================================
--- conf/common.rmk     (revision 2070)
+++ conf/common.rmk     (working copy)
@@ -332,7 +332,7 @@
 
 # Commands.
 pkglib_MODULES += minicmd.mod extcmd.mod hello.mod handler.mod \
-        ls.mod cmp.mod cat.mod help.mod search.mod             \
+        ls.mod cmp.mod cat.mod help.mod search.mod clear.mod  \
        loopback.mod fs_uuid.mod configfile.mod echo.mod        \
        terminfo.mod test.mod blocklist.mod hexdump.mod         \
        read.mod sleep.mod loadenv.mod crc.mod parttool.mod pcpart.mod
@@ -382,6 +382,11 @@
 cat_mod_CFLAGS = $(COMMON_CFLAGS)
 cat_mod_LDFLAGS = $(COMMON_LDFLAGS)
 
+# For clear.mod
+clear_mod_SOURCES = commands/clear.c
+clear_mod_CFLAGS = $(COMMON_CFLAGS)
+clear_mod_LDFLAGS = $(COMMON_LDFLAGS)
+
 # For echo.mod
 echo_mod_SOURCES = commands/echo.c
 echo_mod_CFLAGS = $(COMMON_CFLAGS)
Index: commands/clear.c
===================================================================
--- commands/clear.c    (revision 0)
+++ commands/clear.c    (revision 0)
@@ -0,0 +1,50 @@
+/* clear.c - command to clear the terminal screen. */
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2003,2007  Free Software Foundation, Inc.
+ *  Copyright (C) 2003  NIIBE Yutaka <address@hidden>
+ *
+ *  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/types.h>
+#include <grub/misc.h>
+#include <grub/err.h>
+#include <grub/dl.h>
+#include <grub/term.h>
+#include <grub/command.h>
+
+
+static grub_err_t
+grub_cmd_clear (struct grub_extcmd *cmd __attribute__ ((unused)),
+               int argc __attribute__ ((unused)),
+               char **args __attribute__ ((unused)))
+{
+  grub_cls ();
+  return 0;
+}
+
+static grub_command_t cmd;
+
+GRUB_MOD_INIT(clear)
+{
+  (void)mod;                   /* To stop warning. */
+  cmd = grub_register_command ("clear", grub_cmd_clear,
+               0, "Clear the terminal screen.");
+}
+
+GRUB_MOD_FINI(clear)
+{
+  grub_unregister_extcmd (cmd);
+}