#define SUBJECT "world"
#endif
+static char *subject = SUBJECT;
+
+/* Define subject as a char pointer parameter. */
+module_param(subject, charp, 0664);
+/* Parameter description. */
+MODULE_PARM_DESC(subject, "Subject to say hello to.");
+
/* Our init function: returns 0 if successfull, an error code, otherwise. */
static int __init hello_init(void)
{
/* printk is just like printf, but without floating point support. */
- printk(KERN_ALERT "Hello, " SUBJECT "!\n");
+ printk(KERN_ALERT "Hello, %s!\n", subject);
return 0;
}
static void __exit hello_exit(void)
{
/* KERN_ALERT is a string macro prepended to our message. */
- printk(KERN_ALERT "Goodbye, cruel " SUBJECT "!\n");
+ printk(KERN_ALERT "Goodbye, cruel %s!\n", subject);
}
/* Here, we declare our module init and exit functions. */