In conjunction to what Dave posted, which is 100% correct, the 'File.ReadAllBytes' method does not directly support reading files from a URL. It's designed for reading files from local paths on your filesystem.
You need to use a different approach, involving a web request to download the file contents first. You can use the 'HttpClient' class to achieve this, the example below in C# as you did not specify what language you are using -
using System;
using System.Net.Http;
using System.Threading.Tasks;
class Program
{
static async Task Main(string[] args)
{
string fileUrl = "http://localhost/test.exe";
try
{
using (HttpClient client = new HttpClient())
{
HttpResponseMessage response = await client.GetAsync(fileUrl);
response.EnsureSuccessStatusCode();
byte[] bytes = await response.Content.ReadAsByteArrayAsync();
File.WriteAllBytes("local_test.exe", bytes);
Console.WriteLine("File downloaded and saved successfully.");
}
}
catch (HttpRequestException ex)
{
Console.WriteLine($"An error occurred: {ex.Message}");
}
}
}
[EDIT]
If you want to minimize disk activity and keep the file download in memory without leaving a file trace on the disk, you can use the 'HttpClient' to download the file as a byte array -
using System;
using System.Net.Http;
using System.Threading.Tasks;
class Program
{
static async Task Main(string[] args)
{
string fileUrl = "http://localhost/test.exe";
try
{
using (HttpClient client = new HttpClient())
{
HttpResponseMessage response = await client.GetAsync(fileUrl);
response.EnsureSuccessStatusCode();
byte[] bytes = await response.Content.ReadAsByteArrayAsync();
Console.WriteLine("File downloaded and processed in memory.");
}
}
catch (HttpRequestException ex)
{
Console.WriteLine($"An error occurred: {ex.Message}");
}
}
}