check if a text exists in various txt files

The code you have provided seems to be searching for files with the ".htm" extension and checking if they contain the search term "people." However, your original requirement was to search for files containing the name "TOM" in txt files. Let's modify the code to search for "TOM" in txt files instead.

To search for "TOM" in txt files, you need to change the file extension filter from ".htm" to ".txt"

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;

class Program
{
    static void Main(string[] args)
    {
        string startFolder = @"C:\Textfiles\";
        DirectoryInfo dir = new DirectoryInfo(startFolder);
        IEnumerable fileList = dir.GetFiles("*.txt", SearchOption.AllDirectories);
        string searchTerm = "TOM";

        var queryMatchingFiles =
            from file in fileList
            let fileText = GetFileText(file.FullName)
            where fileText.Contains(searchTerm)
            select file.FullName;

        Console.WriteLine($"The term \"{searchTerm}\" was found in:");

        foreach (string filename in queryMatchingFiles)
        {
            Console.WriteLine(filename);
        }

        // Keep the console window open in debug mode.  
        Console.WriteLine("Press any key to exit");
        Console.ReadKey();
    }

    static string GetFileText(string name)
    {
        string fileContents = string.Empty;

        // If the file exists, read its contents.  
        if (File.Exists(name))
        {
            fileContents = File.ReadAllText(name);
        }
        return fileContents;
    }
}