ISO device to connect to DSLR digital camera to print tickets with the file name of each pic taken on all tix?

Makes no sense to me. Ive seen photographers at events in stationary booths and roaming the events. None of those Ive seen have a device like the one you describe. If they dont need something like this why would you? Thats what makes no sense to me. Somehow they manage to keep track without a device like this.