hi all,
i'am new to module programming and was reading lkmpg .I
read some stuff
relating to the /proc filesystem.i have some doubts here.
1) struct proc_dir_entry {
....
....
struct file_operations * proc_fops;
....
void *data;
read_proc_t *read_proc;
write_proc_t *write_proc;
.....
.....
};
1) Now why do we need read_proc and write_proc here ? proc_fops can be
initialise to read,write ...etc function to read and write from the
proc file right ? then why read_proc and write_proc ? I'am sure ive
missed something here ..
2) I initialise read_proc as below .
struct proc_dir_entry *temp_proc_file;
temp_proc_file->read_proc = procfile_read;
int procfile_read(char *buffer,
char **buffer_location,
off_t offset,
int buffer_length,
int zero) {
what does char **buffer_location and char *buffer mean here ?
i tried :
*buffer_location = my_buffer; /* as given in the example */
it works fine when i do a cat /proc/myfile - it displays
whatever is
there in my_buffer (i.e set by me ).
But where is **buffer_location actually ? and please let me
know what char *buffer means up there .
Hope i was clear. Thanks for u r time.
cheers,
Amith
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