Question

After referring many blogs and articles, I have reached at the following code for searching for a string in all files inside a folder. It is working fine in my tests.

QUESTIONS

1. Is there a faster approach for this (using C#)?
2. Is there any scenario that will fail with this code?

Note: I tested with very small files. Also very few number of files.

CODE

static void Main()
    {
        string sourceFolder = @"C:\Test";
        string searchWord = ".class1";

        List<string> allFiles = new List<string>();
        AddFileNamesToList(sourceFolder, allFiles);
        foreach (string fileName in allFiles)
        {
            string contents = File.ReadAllText(fileName);
            if (contents.Contains(searchWord))
            {
                Console.WriteLine(fileName);
            }
        }

        Console.WriteLine(" ");
        System.Console.ReadKey();
    }

    public static void AddFileNamesToList(string sourceDir, List<string> allFiles)
    {

            string[] fileEntries = Directory.GetFiles(sourceDir);
            foreach (string fileName in fileEntries)
            {
                allFiles.Add(fileName);
            }

            //Recursion    
            string[] subdirectoryEntries = Directory.GetDirectories(sourceDir);
            foreach (string item in subdirectoryEntries)
            {
                // Avoid "reparse points"
                if ((File.GetAttributes(item) & FileAttributes.ReparsePoint) != FileAttributes.ReparsePoint)
                {
                    AddFileNamesToList(item, allFiles);
                }
            }

    }

REFERENCE

1. Using StreamReader to check if a file contains a string
2. Splitting a String with two criteria
3. C# detect folder junctions in a path
4. Detect Symbolic Links, Junction Points, Mount Points and Hard Links
5. FolderBrowserDialog SelectedPath with reparse points
6. C# – High Quality Byte Array Conversion of Images

Answer 1

Instead of File.ReadAllText() better use

File.ReadLines(@"C:\file.txt");

It returns IEnumerable (yielded) so you will not have to read the whole file if your string is found before the last line of the text file is reached