Re^6: Regex Optional capture doesn't (updated)

> can find a way to do what I need with a single regex.

"single regex" is relative in Perl since you can include Perl-code investigating a sub-match

Does it must be a single regex, or is it just academic curiosity?

edit

you need a positive condition which allows to stop the non-greedy only if you have a match or you reached the end.

  DB<113> print join "|",'a<b1<b2' =~ /(a).+?(?:(c.)|$)/
a|

  DB<114> print join "|",'a<b1<c2' =~ /(a).+?(?:(c.)|$)/
a|c2

  DB<115> print join "|",'a<c1<c2' =~ /(a).+?(?:(c.)|$)/
a|c1
[download]

Try to apply this technique.

HTH

Cheers Rolf
_{(addicted to the Perl Programming Language and ☆☆☆☆ :)

Je suis Charlie!}

Comment on Re^6: Regex Optional capture doesn't (updated) Download Code

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Re^7: Regex Optional capture doesn't (updated) by NetWallah (Canon) on Oct 05, 2017 at 17:57 UTC
More like a perverse obsession. Thanks for your tip on "use re 'debug'". It shows that the RE gets confounded by the <Unwanted> tag. Removing that tag allows the regex to capture both items I want. However, this is not an option while I'm parsing the log. All power corrupts, but we need electricity.	[reply]
Re^8: Regex Optional capture doesn't (solved !) by LanX (Saint) on Oct 05, 2017 at 18:07 UTC
my proposition from the edit here works for me with your data: `DB<132> p $x <blah1 phase="2" type="MyType" more_keys="Values" <Unwanted/> <SomeTa +gIwant><k1="v1"></SomeTagIwant> DB<133> $re = qr/\btype="([^"]+)".+?<(\w+TagIwant\b\|$)/ DB<134> print join "\|", $x =~ $re MyType\|SomeTagIwant` [download] update `DB<154> p $x <blah1 phase="2" type="MyType" more_keys="Values" <Unwanted/> <SomeTa +gIwant><k1="v1"></SomeTagIwant> DB<155> p $y <blah1 phase="2" type="MyType" more_keys="Values" <Unwanted/> DB<156> $re = qr/ \btype = "([^"]+)" .+? (?: < ( \w+TagIwant)\b \| $ + ) /x DB<157> print join "\|", $x =~ $re MyType\|SomeTagIwant DB<158> print join "\|", $y =~ $re MyType\|` [download] Cheers Rolf _{(addicted to the Perl Programming Language and ☆☆☆☆ :) Je suis Charlie!}	[reply] [d/l] [select]
Re^9: Regex Optional capture doesn't (solved ?) by NetWallah (Canon) on Oct 05, 2017 at 18:33 UTC
Excellent - your "Update" one works ! The pre-update fails when the tag is absent. I saw this the same time as hauxex's working solution, below .. So I declare both winners ! Thanks. All power corrupts, but we need electricity.	[reply]