Question

I have some MP3 files that are named with a particular syntax, for example:

1 – Sebastian Ingrosso – Calling (Feat. Ryan Tedder)

I have written a small program in C# that reads the Track, Artist and Title from the ID3 tags. What i would like to do is write a regex expression that can validate that the files are in fact named with the syntax listed above.

So i have a class called song:

 //Properties
public string Filename
{
    get { return _filename;  }
    set { _filename = value; }
}

public string Title
{
    get { return _title;  }
    set { _title = value; }
}

public string Artist
{
    get { return _artist;  }
    set { _artist = value; }
}


//Methods

public bool Parse(string strfile)
{
    bool CheckFile;

    Tags.ID3.ID3v1 Song = new Tags.ID3.ID3v1(strfile, true);
    Filename = Song.FileName;
    Title = Song.Title;
    Artist = Song.Artist;


    //Check File Name Formatting
    string RegexBuilder = @"\d\s-\s" + Artist + @"\s-\s" + Title;
    if (Regex.IsMatch(Filename, RegexBuilder))
    {
        CheckFile = true;
    }
    else
    {
        CheckFile = false;
    }
    return CheckFile;
 }

So it works, MOST OF THE TIME. The minute i have a (Feat. ) in the title it fails. The closest i could come up with is:

\d\s-\s\Artist\s-\s.*

That’s obviously not going to work as any text would pass the test, I have tried my very best but I have only been programming for two weeks.

---

tl;dr Would like song to pass a regex test whether it contains a featured artist or not, for example:

1 – Sebastian Ingrosso – Calling (Feat. Ryan Tedder)

and

1 – Flo Rida – Whistle

Should both pass the test.

Answer 1

The problem is that the “(” and “)” in your regex have meaning to the Regex engine. You should use the following code:

string RegexBuilder = @"\d\s-\s" + Regex.Escape(Artist) + @"\s-\s" + Regex.Escape(Title);

The Escape function will change “(Feat. )” to “\(Feat. \)”, which will ensure that you are matching the parentheses and not grouping “Feat. “.

http://msdn.microsoft.com/en-us/library/system.text.regularexpressions.regex.escape.aspx