C#•4mo ago

How to Read byte by byte until EOF?

Hello! I couldn't find an answer on the internet on this question so I guess I will have to ask it. I am trying to make my own version of WinRar and to avoid using too much RAM I want to read and write the file byte by byte. How do I do it? Here's the code:

using System;
using System.IO;

namespace Paxer;

class Core
{
    public static void writeFile(FileStream _target, string root, string sub_path)
    {
        // What is origin?
        string full_path = Path.Combine(root, sub_path);

        FileInfo file_info = new FileInfo(full_path);
        FileStream _from = new FileStream(full_path, FileMode.Open);

        // Lenghts
        long path_len = sub_path.Length;
        byte[] path_blen = BitConverter.GetBytes(path_len);

        long len = file_info.Length;
        byte[] blen = BitConverter.GetBytes(len);

        // Write
        byte b;
        
        // What to do here ???
    }
}

using System;
using System.IO;

namespace Paxer;

class Core
{
    public static void writeFile(FileStream _target, string root, string sub_path)
    {
        // What is origin?
        string full_path = Path.Combine(root, sub_path);

        FileInfo file_info = new FileInfo(full_path);
        FileStream _from = new FileStream(full_path, FileMode.Open);

        // Lenghts
        long path_len = sub_path.Length;
        byte[] path_blen = BitConverter.GetBytes(path_len);

        long len = file_info.Length;
        byte[] blen = BitConverter.GetBytes(len);

        // Write
        byte b;
        
        // What to do here ???
    }
}

11 Replies

Haxo•4mo ago

I want to point out I don't seek functions like "ReadAllBytes" or "WriteAllBytes"

Lisa•4mo ago

https://learn.microsoft.com/en-us/dotnet/api/system.io.filestream.read?view=net-8.0 ?

FileStream.Read Method (System.IO)

Reads a block of bytes from the stream and writes the data in a given buffer.

Haxo•4mo ago

ok thanks I will read it nvm ignore the ping im stupid

Lisa•4mo ago

FileMode is about how the operating system should open the file. Open it, create a new one and open it, add to an existing file. FileAccess is about the operations you want to do on that file

Haxo•4mo ago

I just haven't noticed FileMode Enum does not contain "Write" item or something like that so I understood how it works thanks anyway I used too much python....

Lisa•4mo ago

:nodd:

Haxo•4mo ago

If I want to write to file it will clear its contents and move pointer to the beggining right? When I decide to write something the pointer will be always at the end? or it depends

Lisa•4mo ago

It depends on the filemode

Haxo•4mo ago

understood

leowest•4mo ago

binary reader/writer exists https://learn.microsoft.com/en-us/dotnet/api/system.io.binarywriter?view=net-8.0 https://learn.microsoft.com/en-us/dotnet/api/system.io.binaryreader?view=net-8.0

Jimmacle•4mo ago

also, reading single bytes at a time isn't very efficient you want a reasonably sized buffer

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How to Read byte by byte until EOF?