How to grep Git commit diffs or contents for a certain word

If you want to find all commits where the commit message contains a given word, use

$ git log --grep=word

If you want to find all commits where "word" was added or removed in the file contents (to be more exact: where the number of occurrences of "word" changed), i.e., search the commit contents, use a so-called 'pickaxe' search with

$ git log -Sword

In modern Git there is also

$ git log -Gword

to look for differences whose added or removed line matches "word" (also commit contents).

A few things to note:

-G by default accepts a regex, while -S accepts a string, but it can be modified to accept regexes using the --pickaxe-regex.

-S finds commits where the number of occurrences of "word" changed, while -G finds commits where "word" appears in the diff.

This means that -S --pickaxe-regex and -G do not do exactly the same thing.

The git diff documentation has a nice explanation of the difference:

To illustrate the difference between -S --pickaxe-regex and -G, consider a commit with the following diff in the same file: + return frotz(nitfol, two->ptr, 1, 0); ... - hit = frotz(nitfol, mf2.ptr, 1, 0); While git log -G"frotz\(nitfol" will show this commit, git log -S"frotz\(nitfol" --pickaxe-regex will not (because the number of occurrences of that string did not change).

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git log's pickaxe will find commits with changes including "word" with git log -Sword

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After a lot of experimentation, I can recommend the following, which shows commits that introduce or remove lines containing a given regexp, and displays the text changes in each, with colours showing words added and removed.

git log --pickaxe-regex -p --color-words -S "<regexp to search for>"

Takes a while to run though... ;-)

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One more way/syntax to do it is: git log -S "word"
Like this you can search for example git log -S "with whitespaces and stuff @/#ü !"

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You can try the following command:

git log --patch --color=always | less +/searching_string

or using grep in the following way:

git rev-list --all | GIT_PAGER=cat xargs git grep 'search_string'

Run this command in the parent directory where you would like to search.

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To use a Boolean connector on a regular expression:

git log --grep '[0-9]*\|[a-z]*'

This regular expression searches for the regular expression [0-9]* or [a-z]* in commit messages.

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This is useful in combination with BFG (Git filter branch - not to be confused with git-filter-branch) and git-filter-repo. It just gets the file paths so that you can feed them into one of the two tools I just mentioned.

A. Relative, unique, sorted, paths:

# Get all unique filepaths of files matching 'password'
# Source: https://stackoverflow.com/a/69714869/10830091
git rev-list --all | (
    while read revision; do
        git grep -F --files-with-matches 'password' $revision | cat | sed "s/[^:]*://"
    done
) | sort | uniq

B. Unique, sorted, filenames (not paths):

# Get all unique filenames matching 'password'
# Source: https://stackoverflow.com/a/69714869/10830091
git rev-list --all | (
    while read revision; do
        git grep -F --files-with-matches 'password' $revision | cat | sed "s/[^:]*://"
    done
) | xargs basename | sort | uniq

This second command is useful for BFG, because it only accept file names and not repo-relative/system-absolute paths.

There you go. Enjoy using these Bash snippets for as much agony as they caused to me. I hate Bash, so why do I keep using it?

Dissection

Get file names/paths only

Any of the following options mean the same (git-rep documentation):

-l

--files-with-matches

--name-only

Instead of showing every matched line, show only the names of files that contain Blockquote

Is your pattern: A. Regex v.s. B. Fixed String?

As for -F, well, it just means use a fixed string instead a regex for pattern interpretation. A source.

Another useful note that belongs here: You can throw in -i or --ignore-case to be case insensitive.

Get rid of that stupid leading commit hash

sed "s/[^:]*://"

Source.

Get them unique paths!

| sort | uniq

Who wants duplicate paths? Not you, not me! Oh hey look, they are sorted too! Enjoy.

Source: me. I have used this for as long as I can remember. (man sort and man uniq)

What about file names without paths?

xargs basename

You would think | basename would work, but no. It does not accept input standard input, but as command line arguments. Here's an explanation for that. Go figure! basename basically returns the stem filename without its leading path. man basename.

For method A., I want absolute paths not relative.

Sure, just slap a realpath at the end. Like so:

) | sort | uniq | xargs realpath

Of course you have to use xargs because realpath does not use standard input for input. It uses command-line arguments. Just like dirname.

Inspirations

Check out this awesome alternative answer.

Search all of Git history for a string

File names only using Git grep

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vim-fugitive is versatile for that kind of examining in Vim.

Use :Ggrep to do that. For more information you can install vim-fugitive and look up the turorial by :help Grep. And this episode: exploring-the-history-of-a-git-repository will guide you to do all that.

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If you want search for sensitive data in order to remove it from your Git history (which is the reason why I landed here), there are tools for that. GitHub as a dedicated help page for that issue.

Here is the gist of the article:

The BFG Repo-Cleaner is a faster, simpler alternative to git filter-branch for removing unwanted data. For example, to remove your file with sensitive data and leave your latest commit untouched), run:

bfg --delete-files YOUR-FILE-WITH-SENSITIVE-DATA

To replace all text listed in passwords.txt wherever it can be found in your repository's history, run:

bfg --replace-text passwords.txt

See the BFG Repo-Cleaner's documentation for full usage and download instructions.

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