How to use RegEx to find a set of file name paths in a string

Question

Good morning, guys

Is there a good way to use regex in C # to find all file names and their paths within a variable string?

For example, if you have this line:

string s = @"Hello John

these are the files you have to send us today: <file>C:\Development\Projects 2010\Accounting\file20101130.csv</file>, <file>C:\Development\Projects 2010\Accounting\orders20101130.docx</file>

also we would like you to send <file>C:\Development\Projects 2010\Accounting\customersupdated.xls</file>

thank you";

Result:

C:\Development\Projects 2010\Accounting\file20101130.csv
C:\Development\Projects 2010\Accounting\orders20101130.docx
C:\Development\Projects 2010\Accounting\customersupdated.xls

Editorial: Given what @Jim said, I edited the line adding tags to make it easier to extract the necessary file names from the line!

Answer 1

Here I came up with something:

using System;
using System.Text.RegularExpressions;

public class Test
{

    public static void Main()
    {
        string s = @"Hello John these are the files you have to send us today: 
            C:\projects\orders20101130.docx also we would like you to send 
            C:\some\file.txt, C:\someother.file and d:\some file\with spaces.ext  

            Thank you";

        Extract(s);

    }

    private static readonly Regex rx = new Regex
        (@"[a-z]:\\(?:[^\\:]+\\)*((?:[^:\\]+)\.\w+)", RegexOptions.IgnoreCase);

    static void Extract(string text)
    {
        MatchCollection matches = rx.Matches(text);

        foreach (Match match in matches)
        {
            Console.WriteLine("'{0}'", match.Value);
        }
    }

}

Produces: (see ideone )

'C:\projects\orders20101130.docx', file: 'orders20101130.docx'
'C:\some\file.txt', file: 'file.txt'
'C:\someother.file', file: 'someother.file'
'd:\some file\with spaces.ext', file: 'with spaces.ext'

( ), .

---

, <file>. Extract :

private static readonly Regex rx = new Regex
    (@"<file>(.+?)</file>", RegexOptions.IgnoreCase);

static void Extract(string text)
{
    MatchCollection matches = rx.Matches(text);

    foreach (Match match in matches)
    {
        Console.WriteLine("'{0}'", match.Groups[1]);
    }
}

ideone.

Answer 2

, , :

string s = @"Hello John

these are the files you have to send us today: C:\Development\Projects 2010\Accounting\file20101130.csv, C:\Development\Projects 2010\Accounting\orders20101130.docx

also we would like you to send C:\Development\Projects 2010\Accounting\customersupdated.xls

thank you";

Regex regexObj = new Regex(@"\b[a-z]:\\(?:[^<>:""/\\|?*\n\r\0-\37]+\\)*[^<>:""/\\|?*\n\r\0-\37]+\.[a-z0-9\.]{1,5}", RegexOptions.IgnorePatternWhitespace|RegexOptions.IgnoreCase);
MatchCollection fileNameMatchCollection = regexObj.Matches(s);
foreach (Match fileNameMatch in fileNameMatchCollection)
{
    MessageBox.Show(fileNameMatch.Value);
}

1-5 . , , . MSDN , .

Answer 3

If you use a tag <file>, and the final text can also be represented by a formatted XML document (as far as internal xml, that is, text without root tags), you can probably do:

var doc = new XmlDocument();
doc.LoadXml(String.Concat("<root>", input, "</root>"));

var files = doc.SelectNodes("//file"):

or

var doc = new XmlDocument();

doc.AppendChild(doc.CreateElement("root"));
doc.DocumentElement.InnerXml = input;

var nodes = doc.SelectNodes("//file");

Both methods really work and are very object oriented, especially the second.

And will bring better performance.

See also - Don't parse (X) HTML with RegEx