How to find the Git commit that introduced a string in any branch?

I want to be able to find a certain string which was introduced in any commit in any branch, how can I do that? I found something (that I modified for Win32), but git whatchanged doesn't seem to be looking into the different branches (ignore the py3k chunk, it's just a msys/win line feed fix)

git whatchanged -- <file> | \
grep "^commit " | \
python -c "exec(\"import sys,msvcrt,os\nmsvcrt.setmode(sys.stdout.fileno(), os.O_BINARY)\nfor l in sys.stdin: print(l.split()[1])\")" | \
xargs -i% git show origin % -- <file>

It doesn't really matter if your solution is slow.

You can do:

git log -S <whatever> --source --all

To find all commits that added or removed the fixed string whatever. The --all parameter means to start from every branch and --source means to show which of those branches led to finding that commit. It's often useful to add -p to show the patches that each of those commits would introduce as well.

Versions of git since 1.7.4 also have a similar -G option, which takes a regular expression. This actually has different (and rather more obvious) semantics, explained in this blog post from Junio Hamano.

As thameera points out in the comments, you need to put quotes around the search term if it contains spaces or other special characters, for example:

git log -S 'hello world' --source --all
git log -S "dude, where's my car?" --source --all

Here's an example using -G to find occurrences of function foo() {:

git log -G "^(\s)*function foo[(][)](\s)*{$" --source --all

--reverse is also helpful since you want the first commit that made the change:

git log --all -p --reverse --source -S 'needle'

This way older commits will appear first.

Messing around with the same answers:

$ git config --global alias.find '!git log --color -p -S '

• ! is needed because other way, git do not pass argument correctly to -S. See this response
• --color and -p helps to show exactly "whatchanged"

Now you can do

$ git find <whatever>

or

$ git find <whatever> --all
$ git find <whatever> master develop

Mark Longair’s answer is excellent, but I have found this simpler version to work for me.

git log -S whatever

git log -S"string_to_search" # options like --source --reverse --all etc

Pay attention not to use spaces between S and "string_to_search". In some setups (git 1.7.1), you'll get an error like:

fatal: ambiguous argument 'string_to_search': unknown revision or path not in the working tree.
Use '--' to separate paths from revisions

While this doesn't directly answer you question, I think it might be a good solution for you in the future. I saw a part of my code, which was bad. Didn't know who wrote it or when. I could see all changes from the file, but it was clear that the code had been moved from some other file to this one. I wanted to find who actually added it in the first place.

To do this, I used Git bisect, which quickly let me find the sinner.

I ran git bisect start and then git bisect bad, because the revision checked out had the issue. Since I didn't know when the problem occured, I targetted the first commit for the "good", git bisect good <initial sha>.

Then I just kept searching the repo for the bad code. When I found it, I ran git bisect bad, and when it wasn't there: git bisect good.

In ~11 steps, I had covered ~1000 commits and found the exact commit, where the issue was introduced. Pretty great.

Not sure why the accepted answer doesn't work in my environment, finally I run below command to get what I need

git log --pretty=format:"%h - %an, %ar : %s"|grep "STRING"