This is a great solution. I use it with commands like fd --type f --extension conf 'v\d+' src/main/resources/old --exec echo | read s; _rename_old_conf_file $s

Works great with awk (BSD).

Thanks for the explanation of the errors. I wish could up-vote both this and @ThomasDickey answer. With so many different variants of regex used by different tools (vim, awk, git, grep, ect...) it can be a pain trying to remember their differences. Need a translator of some sort.

awk version 20070501

This is very helpful. I am new to zsh. Where can I find some documentation on this feature of zsh. I've skimmed through the documentation printed from the command run-help aliases.