lkmpg/examples/hello-5.c
Jim Huang 50b8dfe6c2 Enforce the customized style for example code
Instead of using tab for indention, the style defaults to 4 spaces for
the sake of compact layout.
2021-07-22 06:58:13 +08:00

71 lines
2.2 KiB
C

/*
* hello-5.c - Demonstrates command line argument passing to a module.
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/stat.h>
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Peter Jay Salzman");
static short int myshort = 1;
static int myint = 420;
static long int mylong = 9999;
static char *mystring = "blah";
static int myintArray[2] = {-1, -1};
static int arr_argc = 0;
/*
* module_param(foo, int, 0000)
* The first param is the parameters name
* The second param is it's data type
* The final argument is the permissions bits,
* for exposing parameters in sysfs (if non-zero) at a later stage.
*/
module_param(myshort, short, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
MODULE_PARM_DESC(myshort, "A short integer");
module_param(myint, int, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
MODULE_PARM_DESC(myint, "An integer");
module_param(mylong, long, S_IRUSR);
MODULE_PARM_DESC(mylong, "A long integer");
module_param(mystring, charp, 0000);
MODULE_PARM_DESC(mystring, "A character string");
/*
* module_param_array(name, type, num, perm);
* The first param is the parameter's (in this case the array's) name
* The second param is the data type of the elements of the array
* The third argument is a pointer to the variable that will store the number
* of elements of the array initialized by the user at module loading time
* The fourth argument is the permission bits
*/
module_param_array(myintArray, int, &arr_argc, 0000);
MODULE_PARM_DESC(myintArray, "An array of integers");
static int __init hello_5_init(void)
{
int i;
pr_info("Hello, world 5\n=============\n");
pr_info("myshort is a short integer: %hd\n", myshort);
pr_info("myint is an integer: %d\n", myint);
pr_info("mylong is a long integer: %ld\n", mylong);
pr_info("mystring is a string: %s\n", mystring);
for (i = 0; i < (sizeof myintArray / sizeof(int)); i++)
pr_info("myintArray[%d] = %d\n", i, myintArray[i]);
pr_info("got %d arguments for myintArray.\n", arr_argc);
return 0;
}
static void __exit hello_5_exit(void)
{
pr_info("Goodbye, world 5\n");
}
module_init(hello_5_init);
module_exit(hello_5_exit);