[Gprename-users] Help files (or Wiki) for Regexes

[Aidan K. <aid...@ya...>]

Having crossed swords repeatedly with the various incarnations of "Regex" in various packages, it would be helpful if the help file (or the SF/Wiki) linked to the relevant instructions for the Regex incarnation being used.
I note the warning about backreferences like "$1" being considered as a Perl variable, so the (large) chunk of Regex interpretation which handles backreferences doesn't work. Subtext : someone in the past has tripped over the "which version of Regex works here" problem.
I've also realised that I've installed gprenamer wrongly, so it won't work for my joe-soap user (message : Failed to load module "canberra-gtk-module"), but does work for a sudo user. That's obviously me having done something wrong, but I haven't worked out what and I do have an adequate work around, so I'll worry about it when I next build a machine.
Wishlist : Ability to read a string of numbers like "20210525" and parse it down to a more-human readable "2021-05-25" (which is an ISO8601 date, obviously - you know, "computer-friendly"). That is why I was looking for TFM of the Regex system. I suspected I'd need the backreferences bits of Regex black magic, but ... no TFM.