On Thu, 2007-05-31 at 23:06 -0500, Greg Donald wrote: > On 5/31/07, Thomas De Schampheleire <patrickdepinguin@xxxxxxxxx> wrote: > > IIRC (didn't look this up recently and it's been a while), the return > > value should be the number of characters actually written, so the > > caller (the reader of your proc entry) knows whether an error occurs, > > or how long the buffer is. > > > > In order to write 17, you should use something like > > int len; > > int size = 17; > > len = snprintf(buffer, sizeof(int), "%d", size) > > return len; > > > > I think in order to be correct, you should also handle the offset and > > start values correctly. > > Thanks. I see how that works now. > > Now I'm having trouble getting a random number. I found > get_random_int() in linux/random.h but when I call it I get: > > WARNING: "get_random_int" [/usr/src/simple/mymodule.ko] undefined! > > I am including the header like this: > > #include <linux/random.h> > > Do I have to do something special because it's in a module? You can only use "exported" functions from modules. Functions are exported from the kernel using "EXPORT_SYMBOL(function_name);" For random numbers, maybe take a look at srandom32() to set the random seed and random32() to get a random 32-bit number. Avishay -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
