proc_create() example for kernel module

Question

Can someone give me proc_create() example?

Earlier they used create_proc_entry() in the kernel but now they are using proc_create().

Answer 1

This example will create a proc entry which enables reading access. I think you can enable other kinds of access by changing the mode argument passed to the function. I haven't passed a parent directory because there is no need to. The structure file_operations is where you setup your reading and writing callbacks.

struct proc_dir_entry *proc_file_entry;

static const struct file_operations proc_file_fops = {
 .owner = THIS_MODULE,
 .open  = open_callback,
 .read  = read_callback,
};

int __init init_module(void){
  proc_file_entry = proc_create("proc_file_name", 0, NULL, &proc_file_fops);
  if(proc_file_entry == NULL)
   return -ENOMEM;
  return 0;
}

You can check this example for more details: https://web.archive.org/web/20140912140321/http://www.linux.com/learn/linux-training/37985-the-kernel-newbie-corner-kernel-debugging-using-proc-qsequenceq-files-part-1