Regular Expressions

part of string before a match

PozzaVecia29-Oct-12 10:21

PozzaVecia

29-Oct-12 10:21

I have a path and I want to get the part of a path before my match:

string s1= @"c:\temp\lev1\lev2\lev3\MYWORD\lev5\lev6";
string mtch ="MYWORD"

knowing

s1

and

mtch

I want to get the part of path before mtch, so @"c:\temp\lev1\lev2\lev3\".

I tried with RegEx but I don't know how to be elegant.. I'm only able to find MYWORD position and then use the substring.
Is there a smarter solution?

Re: part of string before a match

Richard Deeming29-Oct-12 10:37

Richard Deeming

29-Oct-12 10:37

Regex seems overkill for this, but you can do it with a zero-width positive lookahead assertion[^]:

string s1 = @"c:\temp\lev1\lev2\lev3\MYWORD\lev5\lev6";
string mtch = "MYWORD";

string pattern = "^.*(?=" + Regex.Escape(mtch) + ")";
// == "^.*(?=MYWORD)"

Console.WriteLine(Regex.Match(s1, pattern).Value);