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#include <linux/module.h>
#include <linux/fs.h>
#include <linux/major.h>
#include <linux/capability.h>
#include <asm/uaccess.h>

static ssize_t sample_char_read(struct file * file, char __user * buf,
                       size_t count, loff_t *ppos)
{
 int err=0;
 char kbuf[32] = "Reading sample char device\n";
 
        printk("sample_char_read size(%ld)\n", count);
 err = copy_to_user((void *) buf, kbuf, strlen(kbuf));
        if (err)
                err = -EFAULT;
  kbuf[32] = '\0';
        return count;
}

static ssize_t sample_char_write(struct file * file, char __user * buf,
                       size_t count, loff_t *ppos)
{
 int err=0;
 char kbuf[100];
        printk("sample_char_write size(%ld)\n", count);
 err = copy_from_user((void *) kbuf, buf, count);
        if (err)
                err = -EFAULT;
        kbuf[count] = '\0';
        printk("The data writen :\n");
        printk("%s\n",kbuf);

        return count;

}

int sample_char_open(struct inode *inode, struct file *filp)
{
       printk("sample_char_open\n");
       return 0;
}

int sample_char_release(struct inode *inode, struct file *filp)
{

       printk("sample_char_release\n");
       return 0;
}

static struct file_operations sample_char_fops = {
       read:          sample_char_read,
       write:         sample_char_write,
       open:          sample_char_open,
       release:        sample_char_release,
};

int major_no;

int init_module(void)
{
       printk("\nLoading the sample char device driver 2\n");

       major_no = register_chrdev(0, "sample_char", &sample_char_fops);
       printk("major no = %d\n",major_no);
       return 0;
}

void cleanup_module(void)
{
       unregister_chrdev(major_no,"sample_char");
       printk("\nUnloading the sample char device driver 2\n");

}