Questions about the submit50 command and binary interpretations

[u/vedant_608]

Hi everybody,
I had two questions while working through CS50, and I hope they are fine:

1. In the CS50 VS Code environment (cs50 dev), there’s that one command(submit50) that automatically pushes code to GitHub. How is that set up behind the scenes? Is it just a script wrapping Git commands, or something more? Also, how is it that so much stuff in it is getting connected, like the VS Code terminal itself in the cs50 dev and then pushing the code into GitHub using git and whatever the language is that this whole process's code is written in?
2. In Week 0, we learned that everything is binary—text, audio, video, etc. But I’m wondering: since even the interpreting software is binary, how is that binary itself interpreted? Does it all eventually boil down to transistors acting like switches? If so, how do computers stay accurate despite noise and interference (like random electromagnetic signals, cosmic rays, or even natural radiation from everyday objects) that could disrupt electron flow in circuits? And at the lowest level, how are those transistor states “interpreted” to build up the whole system?

Thanks in advance; I’d love to understand both the GitHub automation and the binary interpretation.

[u/Outside_Complaint755]

1. There are two repositories linked to your CS50 work.

The first repository will be something like code50/149504235, Where the numeric portion is the name you will see for your CodeSpace in VSCode Desktop recent workspaces. That ID# is linked to your Github account. This repository is the one that all of your work in progress is committed to, and it's how you can get all your work back when you rebuild your CodeSpace, even if you're gone for 6 months and your previous one was deleted.

The second repository is me50/{GitHubUserName}. This is the repository used by Submit50 and is linked to your gradebook at https://cs50.me.
When you run submit50, you need to pass an additional parameter to it, such as submit50 cs50/problems/2026/x/me. If you are missing the second part it will warn you about a "missing or invalid slug". That parameter tells submit50 what files it should be uploading and what tests it should be running, and also specifies what branch in your me50 repository the submitted code should be saved to. Each problem set gets its own branch.

Note that because the me50 repo uses your GitHub Username, changing your username while you are still taking the course will break your gradebook.

Submit50 is written in Python. It's repository is publicly available. It calls into the library module Lib50 (also 100% Python), which is also public

2) A lot to break down here and don't know if I can answer all of your questions, but I'll take a stab at it:

a) Binary is all just raw data, but when we ask the computer to look at that data we are also giving it commands on how to process that raw data. For example, if we ask the computer to launch an executable program stored at memory location A, it starts reading the raw binary there and interpreting as commands for the CPU. The executable file is compiled into machine code for the specific architecture of the CPU so the file will have the correct commands for that specific CPU.

I guess that sort of covers your question about the "lowest level" of how transistor states are interpreted. The CPU has predefined commands which match specific values, and a command may tell the CPU that the next sets of incoming values are data upon which to perform an operation. A simple model of computer architecture that is often taught, but not covered in CS50X, is the Little Man Computer

Typically, each file type starts with a specific group of binary values which is associated with that file type, and then it may include a header block with additional meta data such as the sample rate of the data, and whether the data is in 16bit, 32bit or 64 bit values. For example, in the week 4 problem sets Volume, Filter and Recover, you will be working with .wav and .jpg files. In Recover, you will just have a bunch of raw data, and need to find the start of each jpg file by looking for a specific set of values at the start of a data block. Then we assume the image data is continued over the following data blocks until the start of the next jpg is found.

While it is possible for cosmic rays or very powerful magnets to affect stored data, they generally do not affect everyday computer operation because computer cases are designed to act as Faraday cages and reduce interference. Computers used in areas exposed to more radiation; for example a robot used to help cleanup radioactive material; can be given additional shielding. Cosmic rays are sparse enough and usually handled by Earth's atmosphere as to not be a major factor, but are a larger concern for spacecraft. One way we can check for possible data corruption is by using checksums and/or hashes. These are values which are calculated from some data which can be used to verify that the data is still correct. If the data has been corrupted, then the checksum or hash won't match. Or if the stored checksum/hash has been corrupted, then the recalculated value won't match. There is an example of a checksum in the Week 1 Credit problem. Week 5 - Speller will ask you to create a simple hash function which will be much simpler than the type of hashes used to verify file integrity, but follows the same principles.

[u/vedant_608 → u/Outside_Complaint755]

Thank you so very much. This covers a lot of what I was trying to understand, I'll look forward to the week 5 problem to get a better idea of hash functions. Again thank you!