[jraph]

Nice one, I'll try to counter this garbage GPT3 answer:

- I don't think the regex engine in Perl is implemented in Perl. It's probably implemented in C/C++, like grep. libpcre is in C anyway.

- Even if grep is/were more efficient, You might have consumed more time and energy thinking, typing and running "grep --only-matching --perl-regexp 'prefix \K\d+(?= suffix)'" than the suggested perl solution

- I might have consumed even more energy typing this reply. My computer is there, waiting for me typing, doing not much.

[tryauuum]

shorter version of the grep command is

    grep -oP 'prefix \K\d+(?= suffix)'

but yeah, I know it's easier to me because I did read man page at some point (while carefully avoiding perl manuals)

actually even that is not true, perldoc on regular expressions really helps even grep users

[jraph]

In all honesty, I'm more likely to remember this form than the Perl one, and once it's in the shell history, any will do anyway :-)