See https://hashcat.net/trac/ticket/567 . cpu hashcat currently does not have this feature, but next version 0.50 will allow you to use --show --username (well, indeed it works already with 0.49 when you do not change the --outfile-format but next version of cpu hashcat will support that too).
oclHashcat does support --username together with --show (and --outfile-format) already. If you have a amd or nv gpu, you can just use oclHashcat also only to use --show --username together with your .pot file.
How --show works:
--show is always used after cracking (i.e. when cracking is already finished)
the general idea is like this:
1. oclHashcat -m 0 --username hash.txt dict.txt # cracking
2. oclHashcat -m 0 --username --show --outfile-format 2 hash.txt #show all user:pass combinations
So again, --show is not used in step 1 (when you start cracking), but after that when already all cracked hashes are in your .pot file
oclHashcat does support --username together with --show (and --outfile-format) already. If you have a amd or nv gpu, you can just use oclHashcat also only to use --show --username together with your .pot file.
How --show works:
--show is always used after cracking (i.e. when cracking is already finished)
the general idea is like this:
1. oclHashcat -m 0 --username hash.txt dict.txt # cracking
2. oclHashcat -m 0 --username --show --outfile-format 2 hash.txt #show all user:pass combinations
So again, --show is not used in step 1 (when you start cracking), but after that when already all cracked hashes are in your .pot file