Regarding writing to /proc entries

ravi ravi.nanjundappa at ap.sony.com
Thu Aug 5 00:25:50 PDT 2004


Hi,
I've created my own /proc entries using linprocfs.c with read and write
permissions like this
" pfs_create_file(root,"EXAMPLE",&myfunc,NULL,NULL,PFS_RDWR); "

and I've associated my own filler function as follows .

static int myfunc(PFS_FILL_ARGS)
{
	printf(" in myfunc() .....\n");
	if(uio->uio_rw ==UIO_WRITE)
		printf(" write request \n");
	else
		printf(" read request \n");
	sbuf_printf(sb, " myfunc function called\n");
	printf(" exiting from myfunc() .....\n");
	return 0;
}


Please read the above statements .
When I run "cat /proc/EXAMPLE" I'll get the follwing o/p on the screen .

OUTPUT:

in myfunc() .....
read request
exiting from myfunc() .....
myfunc function called
in myfunc() .....
read request
exiting from myfunc() .....


Even though I'm checking the operation that is requested with the
conditional statements if (uio->uiorw==UIO_WRITE) and when I run 
"echo 0 > /proc/EXAMPLE " I'm getting the following error 

ERROR:
	/proc/EXAMPLE : Operation not supported

The same error is coming even for process related " ctl " files as well
when I run 
"echo attach /proc/12/ctl " 


Please tell me the reason and solution for this .


Regards,
N Ravi




More information about the freebsd-fs mailing list