Log text to file

Log.cs

if (!Directory.Exists(Variables.LogDirectory)) Directory.CreateDirectory(Variables.LogDirectory);

var logFile = $"[{DateTime.Now:yyyy-MM-dd}] Log.txt";
if (error) logFile = $"[{DateTime.Now:yyyy-MM-dd}] ErrorLog.txt";

logFile = Path.Combine(Variables.LogDirectory, logFile);

using (var stream = new FileStream(logFile, FileMode.Append, FileAccess.Write))
using (var writer = new StreamWriter(stream))
{
    writer.WriteLine($"[{DateTime.Now:O}] {msg}");
    writer.Close();
    stream.Close();
}