Update January 20, 2014 - This old post from 2012 has again become popular on Hacker News. Since first publishing this article, I've learned that the way I presented editing hunks in the second video, where I show how to edit the line spans at the top of the diff, is both not very efficient and rarely necessary. Hopefully the rest of that video is still useful.
git and GitHub have revolutionized not only how I do development, but how we developers share code.
I have two tools I need to do software development: an editor and version control.
The Pragmatic Programmer advocates you should know your editor inside and out. So why don't you know your version control system just as well?
If you use git, you've used the command git add. But do you know about git add's "patch mode" using git add -p ?
Patch mode allows you to stage parts of a changed file, instead of the entire file. This allows you to make concise, well-crafted commits that make for an easier to read history.
Since I learned about it a year or so ago, patch mode has taken my git usage to another level. It's one of the most powerful git commands, right up there with rebasing, but much less dangerous!
I have recorded two 10-minute screencasts about how I use git add's patch mode. And I want to share them with you for free.
In the first video I walk you through why patch mode is something you should be using today, then demonstrate its basic features.
In the second video I talk through the dark art of editing hunks. Even some of the most knowledgeable git users I know have struggled with this! To really master patch mode you will want to know how to edit hunks. Never fear "patch does not apply" again!
I hope that after watching you will be armed with a new skill you can start using right away and begin to know git at a deeper level.