CODEWITHSUNDEEP
.netregex
camios
camios

Reputation: 342

Less greedy .NET regex

I'm trying to match strings similar to Lookup("lookup name", "lookup key") so I can replace the "lookup key".

I've got a pattern where the lookup key is "3" or 3:

[lL][oO][oO][kK][uU][pP]\(.*?,[ ]*("3"|3)\)

But when I use it on the following input string (which has nested calls) it matches the entire string except for the last parenthesis.

LOOKUP("lookup name1",LOOKUP("lookup name2",3))

How do I get it to just match the last part LOOKUP("lookup name2",3) ?

Upvotes: 1

Views: 59

Answers (1)

zx81
zx81

Reputation: 41838

Directly Matching and Replacing the Key

This matches your lookup key directly!

(?i)(?<=lookup\([^(),]*,)[^()]*?(?=\))

See demo.

You can then replace it with whatever you like:

resultString = Regex.Replace(yourString, @"(?i)(?<=lookup\([^(),]*,)[^()]*?(?=\))", "whatever");

This works because the .NET regex engine supports infinite lookbehinds.

Explanation

  • (?i) puts us in case-insensitive mode
  • (?<=lookup\([^(),]*,) is a lookbehind that asserts that what precedes us is the literal lookup(, then any characters that are not parentheses or commas, then a comma
  • The character class [^()]*? lazily matches any characters that are not parentheses (this is our match!)
  • The lookahead (?=\) asserts that what follows is a closing parenthesis

Reference

Upvotes: 4

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