src/kernel/linux/v4.19/samples/kdb/kdb_hello.c

/*
 * Created by: Jason Wessel <jason.wessel@windriver.com>
 *
 * Copyright (c) 2010 Wind River Systems, Inc.  All Rights Reserved.
 *
 * This file is licensed under the terms of the GNU General Public
 * License version 2. This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 */

#include <linux/module.h>
#include <linux/kdb.h>

/*
 * All kdb shell command call backs receive argc and argv, where
 * argv[0] is the command the end user typed
 */
static int kdb_hello_cmd(int argc, const char **argv)
{
	if (argc > 1)
		return KDB_ARGCOUNT;

	if (argc)
		kdb_printf("Hello %s.\n", argv[1]);
	else
		kdb_printf("Hello world!\n");

	return 0;
}


static int __init kdb_hello_cmd_init(void)
{
	/*
	 * Registration of a dynamically added kdb command is done with
	 * kdb_register() with the arguments being:
	 *   1: The name of the shell command
	 *   2: The function that processes the command
	 *   3: Description of the usage of any arguments
	 *   4: Descriptive text when you run help
	 *   5: Number of characters to complete the command
	 *      0 == type the whole command
	 *      1 == match both "g" and "go" for example
	 */
	kdb_register("hello", kdb_hello_cmd, "[string]",
		     "Say Hello World or Hello [string]", 0);
	return 0;
}

static void __exit kdb_hello_cmd_exit(void)
{
	kdb_unregister("hello");
}

module_init(kdb_hello_cmd_init);
module_exit(kdb_hello_cmd_exit);

MODULE_AUTHOR("WindRiver");
MODULE_DESCRIPTION("KDB example to add a hello command");
MODULE_LICENSE("GPL");