Git & GitHub Course
Git & GitHub
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Intermediate

Repository History

Definition

The chronological log of all commits made in a repository, representing the entire timeline of changes from the project's inception.

Explain Like I'm New

The ledger. Every time someone makes a 'save' (commit), Git writes down Who did it, When they did it, What message they wrote, and a massive string of random letters and numbers (a Hash) that uniquely identifies that exact moment in time.

Real World Example

Looking through the history of Wikipedia edits to see who added a specific paragraph to an article, and when.

Common Use Cases

  • •Auditing changes
  • •Finding when a bug was introduced
  • •Restoring lost code

Terminal Output

bash / terminal
# View the full history $ git log /* Output Example: commit 8f9b2d3c4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b (HEAD -> main) Author: John Doe <john@example.com> Date: Tue Oct 10 14:32:11 2023 -0400 Fix the login button alignment commit 1a2b3c4d5e6f7a8b9c0d1e2f3a4b5c6d7e8f9a0b Author: Jane Smith <jane@example.com> Date: Mon Oct 9 09:15:00 2023 -0400 Initial commit */

Interview Questions

basic

  • What command lets you view the repository history?

intermediate

  • What is a 'Commit Hash' (or SHA-1)?

Flash Cards

Question

View history?

Click to reveal answer
Answer

`git log`

Question

Commit Hash?

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Answer

It is a 40-character cryptographic string (like `a1b2c3d4...`) that uniquely identifies a specific commit. It is mathematically generated based on the contents of the files, so it is impossible to forge.