Question

How to insert text in a text file in C#

Answer 1

using System;
using System.IO;

namespace insert_text_in_textfile
{
    class Program
    {
        static void Main(string[] args)
        {
            FileStream fs = new FileStream("d:\\test.txt", FileMode.Open, FileAccess.ReadWrite);
        
            StreamReader sr = new StreamReader(fs);
            StreamWriter sw = new StreamWriter(fs);

            string s, find = "Programming";

            s = sr.ReadToEnd();
            int i = s.IndexOf(find);
            s = s.Insert(i + find.Length, " PHP,");
            fs.Position = 0;
            fs.SetLength(s.Length);
            sw.Write(s);

            sw.Close();
            sr.Close();
            fs.Close();
        }
    }
}
/*
Before:
 
First Line
Programming C#, C
Next line
*/

/*
After:
 
First Line
Programming PHP, C#, C
Next line
*/

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