How to get date from this string?

Question

I have this string:

\tid <[email protected]>; <b>Tue, 6 Oct 2009 15:38:16</b> +0100

and I want to extract the date (emboldened) to a more usable format, e.g. 06-10-2009 15:38:16

What would be the best way to go about this?

Solution 1

Regex might be overkill. Just Split on ';', Trim(), and call Date.Parse(...), It will even handle the Timezone offset for you.

using System;

namespace ConsoleImpersonate
{
    class Program
    {
        static void Main(string[] args)
        {

            string str = "\tid [email protected]; Tue, 6 Oct 2009 15:38:16 +0100";
            var trimmed = str.Split(';')[1].Trim();
            var x = DateTime.Parse(trimmed);

        }
    }
}

Solution 2

You can try this code (with possible adjustments)

Regex regex = new Regex(
      ";(?<date>.+?)",
    RegexOptions.IgnoreCase
    | RegexOptions.CultureInvariant
    | RegexOptions.IgnorePatternWhitespace
    | RegexOptions.Compiled
    );

var dt=DateTime.Parse(regex.Match(inputString).Groups["date"].Value)

Solution 3

Here's a regex approach to match the format. The date result is formatted as you specified.

string input = @"\tid [email protected]; Tue, 6 Oct 2009 15:38:16 +0100";
// to capture offset too, add "\s+\+\d+" at the end of the pattern below
string pattern = @"[A-Z]+,\s+\d+\s+[A-Z]+\s+\d{4}\s+(?:\d+:){2}\d{2}";
Match match = Regex.Match(input, pattern, RegexOptions.IgnoreCase);

if (match.Success)
{
    string result = match.Value.Dump();
    DateTime parsedDateTime;
    if (DateTime.TryParse(result, out parsedDateTime))
    {
        // successful parse, date is now in parsedDateTime
        Console.WriteLine(parsedDateTime.ToString("dd-MM-yyyy hh:mm:ss"));
    }
    else
    {
        // parse failed, throw exception
    }
}
else
{
    // match not found, do something, throw exception
}