llu not working in fscanf ??

given text input from file as:

10000,
020,0xf123456abaff123a, ...

while(!feof(pat)){
fscanf(pat," %llu%*[ ,\n]",&conv); // should convert decimal, octal, or hex notation, but this is not the case...chokes on 'x'

using %llx does convert hex, but converts everything else as hex too (which is not the desired behavior).

(some of the *[ ... notation to discard commas and white space may not be optimized)

is this a bug?