What does the caret (^) character mean in Git?

Git

Git Problem Overview

I saw an answer to a question here that helps restore a deleted file in git.

The solution was

git checkout <deleting_commit>^ -- <deleted_file_path>

What does the caret character (^) do? I’ve seen it elsewhere doing very useful things in git. It’s magical. Someone please spoil it for me and tell me what it does?

Git Solutions

Solution 1 - Git

HEAD^ means the first parent of the tip of the current branch.

Remember that git commits can have more than one parent. HEAD^ is short for HEAD^1, and you can also address HEAD^2 and so on as appropriate.

You can get to parents of any commit, not just HEAD. You can also move back through generations: for example, master~2 means the grandparent of the tip of the master branch, favoring the first parent in cases of ambiguity. These specifiers can be chained arbitrarily , e.g., topic~3^2. See related answer to What’s the difference between HEAD^ and HEAD~ in Git?

For the full details, see the “Specifying Revisions” section of git rev-parse --help.

Solution 2 - Git

It means "parent of". So HEAD^ means "the parent of the current HEAD". You can even chain them together: HEAD^^ means "the parent of the parent of the current HEAD" (i.e., the grandparent of the current HEAD), HEAD^^^ means "the parent of the parent of the parent of the current HEAD", and so forth.

Solution 3 - Git

The ^ (caret) can also be used when specifying ranges.

> To exclude commits reachable from a commit, a prefix ^ notation is > used. E.g. ^r1 r2 means commits reachable from r2 but exclude the ones > reachable from r1. > > <rev> > > Include commits that are reachable from (i.e. ancestors of) . > > ^<rev> > > Exclude commits that are reachable from (i.e. ancestors of) .

Solution 4 - Git

Here's a visual explanation. Suppose you have a history like so:

                      master  
  ... <- B <- C <- D
             /
... <- E <- F
              feature

When feature was merged into master, C was created with two ancestors. Git assigns these ancestors numbers. The mainline ancestor B is assigned 1 and the feature ancestor F is assigned 2.

Thus C^1 refers to B and C^2 refers to F. C^ is an alias for C^1.

You would only ever use <rev>^3. if you had performed a merge of three branches.

Solution 5 - Git

The caret refers to the parent of a particular commit. E.g. HEAD^ refers to the parent of the current HEAD commmit. (also, HEAD^^ refers to the grandparent).

Solution 6 - Git

The carat represents a commit offset (parent). So for instance, HEAD^ means "one commit from HEAD" and HEAD^^^ means "three commits from HEAD".

Solution 7 - Git

The (^) gets the parent source of the command i.e. HEAD^ will get the parent of HEAD.

Solution 8 - Git

Greg Bacon gave a great link, but it's pretty dense. The Git introductory docs online also introduce revision and range specifiers:

https://git-scm.com/book/en/v2/Git-Tools-Revision-Selection

Categories
Recommended Git Solutions

Previous Solution:

Parsing a comma-delimited std::string

C++StringParsingStlCsv

Next Solution:

Django - filtering on foreign key properties

DjangoDjango ModelsDjango Queryset

Attributions

All content for this solution is sourced from the original question on Stackoverflow.

The content on this page is licensed under the Attribution-ShareAlike 4.0 International (CC BY-SA 4.0) license.

Content TypeOriginal AuthorOriginal Content on Stackoverflow
QuestionCharles MaView Question on Stackoverflow
Solution 1 - GitGreg BaconView Answer on Stackoverflow
Solution 2 - GitmipadiView Answer on Stackoverflow
Solution 3 - GitcmcgintyView Answer on Stackoverflow
Solution 4 - GitcdosbornView Answer on Stackoverflow
Solution 5 - GitmopokeView Answer on Stackoverflow
Solution 6 - GitAmberView Answer on Stackoverflow
Solution 7 - GitTALLBOYView Answer on Stackoverflow
Solution 8 - GitNcatView Answer on Stackoverflow