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?
HEAD^ means the first parent of the tip of the current branch.
Remember that git commits can have more than one immediate parent. HEAD^ is short for HEAD^1, and you can also address HEAD^2 and so on as appropriate. Any commit with multiple parents is the product of a merge or a merge commit.
You can get to parents of any commit, not just HEAD. You can also move back through generations to any reachable ancestor: 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. For example:
HEAD^^^, HEAD~~~, or HEAD~3 all refer to the great-grandparent commit, three generations back. HEAD^3 is different: it means the third immediate parent of a merge commit — and strains the analogy to biology.topic~3^2 starts at the tag or tip of the branch named topic, goes three generations back, and selects that merge commit’s (the great-grandparent’s) second immediate parent — the great-great-grandfather if you think of git history as being primarily matrilineal.See also:
HEAD^ and HEAD~ in Git?git rev-parse --helpThe ^ (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) .
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.
HEAD is following a merge commit, then HEAD^ means the first parent of HEAD, and HEAD^^ (or HEAD^2) means the second parent of HEAD. In a merge commit, the second parent of HEAD is not the same thing as the parent of the parent of HEAD. See Ancestry References in the Git manual.
HEAD^2 does indeed indicate the second parent of HEAD, HEAD^2 and HEAD^^ are not synonymous. Multiple carets do refer to commits in relation to the first parent, so just as HEAD^^ refers in general to the grandparent of HEAD, HEAD^^ the grandparent of parent of the first commit of HEAD when HEAD is a merge commit; likewise, HEAD^2^ is the parent of the second parent.HEAD~~ and HEAD~2 are synonymous, so by analogy, I expected the number operator to work similarly with the caret. From what you are saying, it does not. That is unfortunate.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.
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).
OP: What does the caret (^) character mean in Git?
The difference between HEAD^ (Caret) and HEAD~ (Tilde) is how they traverse history backwards from a specified starting point, in this particular case HEAD.
<rev>~[<n>] = select <n>th generation ancestor, following only first* parents
<rev>^[<n>] = select <n>th parent of first generation ancestors
*First parent is always the left hand side of the merge, e.g. the commit on the branch that got merged into.
As seen in the illustration below the two selectors ~ and ^ can be used in combination. Also note that instead of using HEAD as a starting point, any regular reference can be used such as a branch, tag or even a commit hash.
Further more, depending on what ancestor is intended to be selected ^ and ~ can be used interchangeably as seen below in the table.
Source: A thorough rundown can be found in this blog post on the subject.
The carat represents a commit offset (parent). So for instance, HEAD^ means "one commit from HEAD" and HEAD^^^ means "three commits from HEAD".
The (^) gets the parent source of the command i.e. HEAD^ will get the parent of HEAD.
Greg Bacon gave a great link, but it's pretty dense. The Git introductory docs online also introduce revision and range specifiers:
^) is the escape character in cmd.exe. Every time I've tried to use it to see if it would be helpful I was actually passing nothing, which explains why the results were never different. >_> Stupid cmd.exe. You can escape it by doubling it or quoting it:git log master^^orgit log "master^"