Search in git history

Often, I need to retrieve a deleted code snippet from Git’s history. The usual flow is to remember the commit message and fuzzy search it in the git log. Then I look at the diffs in the commit to get the snippet.

I decided to make the process easier and write a bash script. But, while looking for the right Git commands and flags, I found the solution already implemented in Git. There are two general strategies to approach the problem: search by location and search by name. Which approach we use depends on what we remember about the code snippet.

Let’s take a scenario where we remember vaguely the location of the code snippet. Something like ‘on the bottom of the file utils.py’. If the file is 60 lines long and the snippet is about ten lines of code, we can find it with the following command.

git log -L 50,60:utils.py

We’ll get a list of all commits with diffs in the given location. Then we can find the snippet in the list.

The second strategy requires information about a unique string, such as the name of a function or variable, to filter out the results better. Let’s say we’re looking for a function get_valid_ports.

git log --patch -S "get_valid_ports"

Now, we’ll get all commits containing get_valid_ports.

I know we won’t need this daily, but it’s nice to know this kind of search is possible and easy. Git is far more powerful than just clone, commit and push. Solid knowledge of it will save us priceless time.