Issue while compiling make file for linux kernel?

Question

I have just started with linux kernel development and I am having issue with compiling make file.

It is the tutorial of hello world.

My hello-1.c file

*
* hello−1.c − The simplest kernel module.
*/
#include <linux/module.h>
/* Needed by all modules */
#include <linux/kernel.h>
/* Needed for KERN_INFO */
int init_module(void)
{
printk(KERN_INFO "Hello world 1.\n");
/*
* A non 0 return means init_module failed; module can't be loaded.
*/
return 0;
}
void cleanup_module(void)
{
printk(KERN_INFO "Goodbye world 1.\n");
}

My Makefile

obj−m += hello−1.o

all:
        make −C /lib/modules/$(shell uname −r)/build M=$(PWD) modules

clean:
        make −C /lib/modules/$(shell uname −r)/build M=$(PWD) clean

Both of this file are in folder /home/kkr/Documents/HelloWorld

When i run the make command I am getting below output.

uname: extra operand `−r'
Try `uname --help' for more information.
make −C /lib/modules//build M=/home/kkr/Documents/HelloWorld modules
make[1]: Entering directory `/home/kkr/Documents/HelloWorld'
make[1]: *** No rule to make target `−C'.  Stop.
make[1]: Leaving directory `/home/kkr/Documents/HelloWorld'
make: *** [all] Error 2

Can any body have any idea what is the root cause ? I know it is very simple still I am not able to come out from this ?

Thanks

Answer 1

$(shell uname −r)
              ^
           This is not a - (dash , minus) character.

You want

$(shell uname -r)