They are truly a dark & secret art imo.
If I have: %cats% are nice but %strings% are stringy, how do I match 'cats' and 'strings' but not the bit in the middle?
― Gravel Puzzleworth, Sunday, 9 January 2011 22:02 (thirteen years ago) link
I don't know what language/engine you're using, but you may be able to switch it between "greedy" (use the biggest possible matching chunk of the input) vs "non-greedy" (match as little as possible) - if you're in perl, swapping * or + for *? or +? is one way to force a non-greedy match
or you could just tell it to match anything which isn't a % symbol by matching a character class of not %, i.e. ^% in square brackets
Default greedy match:
perl -e "$s = '%cats% are nice but %strings% are stringy'; @matches = ($s =~ m/%(.*)%/g); print @matches"
cats% are nice but %strings
Forcing non-greedy with *?:
perl -e "$s = '%cats% are nice but %strings% are stringy'; @matches = ($s =~ m/%(.*?)%/g); print @matches"
cats
strings
Using the character class to exclude %s -- ^% in square brackets means any character except %:
perl -e "$s = '%cats% are nice but %strings% are stringy'; @matches = ($s =~ m/%(<^%>*)%/g); print @matches"
cats
strings
(replace <> in bold with square brackets, forgotten how to get round ILXBBcode)
― agrarian gamekeeper (a passing spacecadet), Sunday, 9 January 2011 22:23 (thirteen years ago) link
ILX-code woes made me remove the bit where I set $, to \n for human-readable output; posted it and then realised I could just have used any character except curly braces after my qq
― agrarian gamekeeper (a passing spacecadet), Sunday, 9 January 2011 22:26 (thirteen years ago) link
the bit in the middle u mean? because that % symbol ("% are ...") has already been matched in its "%cats%" incarnation.
iow "%(.*?)%" will match "%cats%", the processor will then go to work on the remaining part, "are nice but %strings% are stringy", and match "%strings%".
― nanoflymo (ledge), Monday, 10 January 2011 09:47 (thirteen years ago) link