Linux character driver Template

Linux character driver template-general Linux technology-Linux programming and kernel information. The following is a detailed description. The linux character driver template is applicable to kernels smaller than 2.4.

# Include
# Include
# Include
# Include
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# Include
# Include


# Define MAJOR_NUM 125
# Define DEVICE_NAME "emptychr"

Static ssize_t test_read (struct file * file, char * buf, size_t count, loff_t * f_pos)
{
Return count;
}
Static ssize_t test_write (struct file * file, const char * buf, size_t count, loff_t * f_pos)
{
Return count;
}
Static int test_open (struct inode * inode, struct file * file)
{
MOD_INC_USE_COUNT;
Return 0;
}
Static int test_release (struct inode * inode, struct file * file)
{
MOD_DEC_USE_COUNT;
Return 0;
}
Static int test_ioctl (struct inode * inode, struct file * file, unsigned int cmd, unsigned long arg)
{
Return 0;
}
Struct file_operations test_fops = {
Read: test_read,
Write: test_write,
Open: test_open,
Release: test_release,
Ioctl: test_ioctl
};
Int test_init (void)
{
Int result;
Result = register_chrdev (MAJOR_NUM, DEVICE_NAME, & test_fops );
If (result <0 ){
Printk (KERN_INFO "test: can't get major number \ n ");
Return result;
}

Printk ("init module \ n ");
Return 0;

}
Void test_exit (void)
{
Unregister_chrdev (MAJOR_NUM, DEVICE_NAME );
Printk ("cleanup_module \ n ");
}


Module_init (test_init );
Module_exit (test_exit );

MODULE_LICENSE ("GPL ");
MODULE_AUTHOR ("huangxb ");