How to split a string on the 3rd occurence of a char C#

Question

I was wondering is there a way to split a string on the 3rd occurence of a char? When splitting previously i was using:

line.Substring(line.LastIndexOf(']') +1);

I hadn't realised some of my strings had extra square brackets than others so ideally i need to split on the 3rd occurence of ']' as this is the same position on every string.

Input: [Wed Dec 17 14:40:28 2014] [error] [client 143.117.101.166] File does not exist:

Output:

[Wed Dec 17 14:40:28 2014] [error] [client 143.117.101.166]

File does not exist:

Answer 1

you need to split the string first then take the index of the 3rd ]

line.Substring(line.IndexOf(line.Split(']')[3]));

or more easy as you said the 3rd index of ] is the same, put it fixed

line.Substring(59);

Answer 2

This input can be matched with a regular expression:

\[[^\]]*\]\s*\[[^\]]*\]\s*\[[^\]]*\]

This looks scary because of escape sequences, but the structure is very straightforward: it matches three occurrences of [ + zero or more non-] + ], separated by zero or more spaces.

var s = "[Wed Dec 17 14:40:28 2014] [error] [client 143.117.101.166] File does not exist:";
var r = new Regex(@"(\[[^\]]*\]\s*\[[^\]]*\]\s*\[[^\]]*\])(.*)$");
var m = r.Match(s);
if (m.Success) {
    Console.WriteLine("Prefix: {0}", m.Groups[1]);
    Console.WriteLine("Error: {0}", m.Groups[2]);
}

Demo.

Answer 3

Use Regex to solve the problem,this will capture content with []

string input = " [Wed Dec 17 14:40:28 2014] [error] [client 143.117.101.166] File does not exist";
var regex = new Regex("\\[(.*?)\\]");
var matches = regex.Matches(input);
foreach (var match in matches) // e.g. you can loop through your matches like this
{
   //yourmatch
}