The problem here is the communication between completely different processes (combinator.bin and oclHashcat-plus64.bin)... the pipe symbol reflects this very well... ( look at | as a wall between the two processes where only some data can flow through)....
The oclHashcat process does not know how the data is being generated ... and how much remaining data there is... to make it clear, not even combinator.bin exaclty knows a priori how "much" data there is and when exactly it is done... think of it this way "it just finishes when it needs to stop - when everything is done"
(To make it clear, oclHashcat can not influence and query the state from the other process(es) - which make part of the pipe - and won't be able to do that in future versions... this is a standard way to seperate but at the same time interact w/ other processes, only allow the flow of data - but don't be able to control the other processes ( besides querying the data slower or faster) )
That said, ther are some workarounds that you can try....
A nice tool for this is pipe viewer (pv, sudo apt-get install pv):
Code:
pv combinator.bin rockyou.txt huge_wordlist.txt | ./oclHashcat-plus64.bin -m 0 m0000.txt --quiet -r rules/best64.rule
This will (magically) show you the amount of data that flows through the pipe and how much data there still may be (I think pv just magically knows the "positions" in the input file(s) - and it sees how much data passes between the processes)
This may not be perfectly accurate but it seems to give you an idea.
Note: pv somehow controls the combinator.bin process (much more than oclHashcat after the pipe does)... also note there is no pipe between pv and combinator.bin here.
Another way to do the same could be to use "named pipes" <(./combinator.bin rockyou.txt huge_wordlist.txt)... the problem is that oclHashcat does not allow to do so, because it needs to have some information about the start and end of the input - if not in stdin mode - (and this information is not available a priori)....
... back to topic, this is the main reason, why oclHashcat does not (allow to) show the status during an attack in stdin mode.... because it does not have the required info for the status screen (e.g. the total amount of passwords/combinations to try etc etc.....) ...
Ofc you could try to convince the devs (by opening a trac ticket) to show (while in stdin mode) a special version of the status screen, where you only see the speed (of pipe and/or cracking speed, should be kind of the same because pipe in most cases is/can be a bottleneck) and other info available.
I think the 'pv' work-around could help you somehow. Let me know if this is working for you... or if not how you think oclHashcat can do better (besides my proposed feature request - very special/reduced/limited version of status screen)