Search Git commit history for a string and see the diffs

search-git-history.md

Searching Git commit history

Original Gist

This should be one of the core features of Git, but for some reason it's impossible to figure out how to search for a string in your commit history and see the diffs that that string is in. Here's the best I've come up with:

To find which commits and which files a string was added or removed in:

git log -S'search string' --oneline --name-status

To see the diff of that

git log -S'search string' -p | grep 'search string' -C5

You can also do a regex search by using -G instead of -S.

Additional much more detailed comment from the original

On that same StackOverflow issue that @raedbenz linked, there is a better answer that basically suggests the same -S 'pickaxe' method described here + goes into some more details about it's usage:

* https://stackoverflow.com/questions/2928584/how-to-grep-search-committed-code-in-the-git-history/2928721#2928721

Since I always find myself ending up back on this gist, here are the methods described in that StackOverflow:

You should use the pickaxe (-S) option of git log. To search for Foo:

git log -SFoo -- path_containing_change
git log -SFoo --since=2009.1.1 --until=2010.1.1 -- path_containing_change

See Git history - find lost line by keyword for more. As Jakub Narębski commented:

• this looks for differences that introduce or remove an instance of <string>. It usually means "revisions where you added or removed line with 'Foo'".
• the --pickaxe-regex option allows you to use extended POSIX regex instead of searching for a string. Example (from git log): git log -S"frotz\(nitfol" --pickaxe-regex

As Rob commented, this search is case-sensitive - he opened a follow-up question on how to search case-insensitive.

Looking at the StackOverflow for case-insensitive pickaxes search:

• https://stackoverflow.com/questions/25384842/case-insensitive-git-pickaxe-search/25385294#25385294

The way the -i is used with pickaxe (see commit accccde, git 1.7.10, April 2012) is:

git log -S foobar -i --oneline
# or
git log --regexp-ignore-case -Sfoobar
# or
git log -i -Sfoobar

Note that with 1.x git versions this option will not work with a regexps, only with a fixed string. It works with regexps only since git 2.0 and commit 218c45a, git 2.0, May 2014.

From:

• https://stackoverflow.com/questions/2928584/how-to-grep-search-committed-code-in-the-git-history/12430097#12430097

My favorite way to do it is with git log's -G option (added in version 1.7.4).

-G<regex>
       Look for differences whose added or removed line matches the given <regex>.

There is a subtle difference between the way the -G and -S options determine if a commit matches:

• The -S option essentially counts the number of times your search matches in a file before and after a commit. The commit is shown in the log if the before and after counts are different. This will not, for example, show commits where a line matching your search was moved.
• With the -G option, the commit is shown in the log if your search matches any line that was added, removed, or changed.

You can combine -p / --patch with any of these methods to get a diff patch of the found commits.

Hopefully saves someone else (or future me) some time! 🖤