Re: regex greediness

The (.*?) in your second attempt is a non-greedy match, which means it will match the smallest possible substring that satisfies the pattern. In this case, it matches an empty string because the optional (?:b=(\w))? can also match the empty string. Use a positive lookahead assertion to ensure that the (.*?) matches up to the optional b=(\w) part, but doesn't include it:

/(a)(?:(.*?)(?:b=(\w)))?/
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Re^2: regex greediness by choroba (Cardinal) on May 29, 2024 at 19:25 UTC
`(?:...)` is a non-capturing group, positive lookahead uses `(?=...)` which I can't find in the regex used. `map{substr$_->[0],$_->[1]\|\|0,1}[\\|\|{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^ARGV,3]`	[reply] [d/l] [select]
Re^3: regex greediness by Anonymous Monk on May 29, 2024 at 20:46 UTC
(?:...) is a non-capturing group, positive lookahead uses (?=...) which I can't find in the regex used. Sorry for the typo, meant to type this, but it's still wrong: `/(a)(?=(.?)(?:b=(\w)))?/` [download] This seems to work: `/(a)(.?)(?=b=(\w)\|\z)/` [download]	[reply] [d/l] [select]