Using StreamReader to check if a file contains a string

by

Are you expecting the file to be particularly big? If not, the simplest way of doing it would be to just read the whole thing:

using (StreamReader sr = new StreamReader("C:\\Work\\list.txt"))
{
    string contents = sr.ReadToEnd();
    if (contents.Contains(args[0]))
    {
        // ...
    }
}

Or:

string contents = File.ReadAllText("C:\\Work\\list.txt");
if (contents.Contains(args[0]))
{
    // ...
}

Alternatively, you could read it line by line:

foreach (string line in File.ReadLines("C:\\Work\\list.txt"))
{
    if (line.Contains(args[0]))
    {
        // ...
        // Break if you don't need to do anything else
    }
}

Or even more LINQ-like:

if (File.ReadLines("C:\\Work\\list.txt").Any(line => line.Contains(args[0])))
{
    ... 
}

Note that ReadLines is only available from .NET 4, but you could reasonably easily call TextReader.ReadLine in a loop yourself instead.

More Related Contents:

  1. Easiest way to read from and write to files
  2. How do I read a specified line in a text file?
  3. How to read an entire file to a string using C#?
  4. Extremely Large Single-Line File Parse
  5. c# search string in txt file
  6. What’s wrong with my function? C# [closed]
  7. Read whole ASCII file into C++ std::string [duplicate]
  8. How do I read an entire file into a std::string in C++?
  9. How would you count occurrences of a string (actually a char) within a string?
  10. How to convert UTF-8 byte[] to string
  11. How can I String.Format a TimeSpan object with a custom format in .NET?
  12. How to access random item in list?
  13. How do I replace multiple spaces with a single space in C#?
  14. Way to have String.Replace only hit “whole words”
  15. Convert string to DateTime in c#
  16. How to parse a string into a nullable int
  17. How to initialize a list of strings (List) with many string values
  18. String interning in .Net Framework – What are the benefits and when to use interning
  19. Alternative to multiple String.Replaces [duplicate]
  20. Split String into smaller Strings by length variable
  21. Removing hidden characters from within strings
  22. can I check if a file exists at a URL?
  23. Convert string to hex-string in C#
  24. Obtain SHA-256 string of a string
  25. Remove file extension from a file name string
  26. Unit Testing File I/O
  27. Does StringBuilder use more memory than String concatenation?
  28. Operator ‘==’ cannot be applied to operands of type ‘char’ and ‘string’
  29. Why is “string” considered a simplified version of “String”?
  30. how to handle spaces in file path if the folder contains the space?

Leave a Comment