Git tricks

I normally collaborate with multiple people using git and their forks within the same repository.

I recently started using a nice feature from Git that allows to fetch several remotes of a give team, allowing me to fetch the remotes that I care about, checkout their branch, collaborate and move on.

# sets the default remotes that I want to fetch when working on my branches
git config remotes.default 'origin upstream'
# sets the group of remotes that I want to fetch as a team
git config remotes.team1 'user1 user2 user3 user4'
git config remotes.team2 'user5 user6 user7 user8'

You can also add the same user that might be in 2 different teams in case you want their fork to be updated when fetching the forks of that team.

There are other nice features in git that I use as a daily basis like git grep.
But one that I use more often that I would think I'd need, is searching the entire history for code:

git rev-list --all | xargs git grep <expression>

This is specially useful to look for previous code that was removed by a commit.

You can even use it in an easier way by doing:

git grep <regexp> $(git rev-list --all)

I find this more useful, because I normally reuse the previous git grep <expression> command (since I was searching for something already) and just append the extra part to search for it in the entire history.

If your code base is really big (like most of the repositories I work with), it will be useful to limit the search to some folder (that you know it didn't change to another folder, or that was in that folder when it was added, changed or deleted).

git grep <regexp> $(git rev-list --all -- some/folder) -- some/folder

The reason for passing the path in both commands is because rev-list will return the revisions list where all the changes to lib/util happened, thus you'll also want to pass to the same folder to grep so that it will only search inside some/folder.

Here are some other useful ways of searching your source:

Search working tree for text matching regular expression regexp:

git grep <regexp>

Search working tree for lines of text matching regular expression regexp1 and/or regexp2:

# notice that `--or` is optional (since it is the default)
git grep -e <regexp1> [--or] -e <regexp2>
git grep -e <regexp1> --and -e <regexp2>

Search working tree for files that have lines of text matching regular expression regexp1 and lines of text matching regular expression regexp2:

git grep -l --all-match -e <regexp1> -e <regexp2>

Search for changed lines of text matching pattern:

git diff --unified=0 | grep <pattern>

Search all revisions between rev1 and rev2 for text matching regular expression regexp. Useful to search for a change between 2 versions:

git grep <regexp> $(git rev-list <rev1>..<rev2>)

Search for removed code or text:

git log -S'removed text'

If you need something like above, but based on a regular expression you can use -G but it will match differences with added/removed lines that match:

git log -G<regex>

You can find other helpful alias in my dotfiles.

I hope you find these feature as neat as I do! 🎉