How to checkout a commit's child?

Question

How do I reference a commit ahead of HEAD?

For example, a commit that is 1 commit behind HEAD is HEAD~1.

How do I move the opposite direction, with respect to HEAD?

Basically, I did a git checkout HEAD~1 3 times. Now I want to move forward 1 commit, effectively undoing my last git checkout HEAD~1. How can I do this?

I understand that a branch of commits is like a singly linked list, with each commit only pointing to its parent. So if it unreasonable to traverse to a commit's child, I would like to know how to process forward between them.

Answer 1

A commit can have unlimited children. If you want to see all the histories that trace back to a commit you can

git log --all --ancestry-path ^$commit

or just

git branch --contains $commit
git tag --contains $commit

to show their names.

with whatever display options you want. If you want to automate finding commits whose parent is a particular commit you could start with

child-commits() { 
        git rev-list --all --ancestry-path --parents ^$1^{} \
        | awk /$(git rev-parse $1^{})'/ {print $1}'
}

---

But if you just want to see where you've been, use

git reflog

to show what's affected your HEAD, and why.