Beej's Guide to Git

I can't help but feel that Git has completely missed the forest through the trees that you can make a 30+ part guide explaining how to use it.

My sense, bluntly, is that if people spent half the effort learning git that they do whining about it, no one would bother making a 30+ part guide just explaining stuff you could find in a man page.

Commits are snapshots of a tree. They have a list of ancestors (usually, but not always, just one). Tags are named pointers to a commit that don't change. Branches are named pointers to a commit that do change. The index is a tiny proto-commit still in progress that you "add" to before committing.

There. That's git. Want to know more? Don't read the guide, just google "how to I switch to a specific git commit without affecting my tree?", or "how do I commit only some of my changed files?", or "how to I copy this commit from another place into my current tree?".

The base abstractions are minimalist and easy. The things you want to do with them are elaborate and complicated. Learn the former, google the latter. Don't read guides.

This doesn’t work. Look:

Commits are sets of files. They form a tree. A branch is a named location in this tree. The index aka staging area is a pre-commit that has no message. Workdir is just workdir, it doesn’t go in the repo unless you stage it. HEAD is whereafter commit will put new changes.

Do I understand git? Seems like yes. Let’s run a quiz then! Q? A.

How to make a branch? Git branch -a? Git checkout -b --new? Idk.

How to switch to a branch? Git switch <name>, but not sure what happens to a non-clean workdir. Better make a copy, probably. Also make sure the branch was fetched, or you may create a local branch with the same name.

How to revert a file in a workdir to HEAD? Oh, I know that, git restore <path>! Earlier it was something git reset -hard, but dangerous wrt workdir if you miss a filename, so you just download it from git{hub,lab} and replace it in a workdir.

How to revert a file to what was staged? No idea.

How to return to a few commits back? Hmmm… git checkout <hash>, but then HEAD gets detached, I guess. So you can’t just commit further, you have to… idfk, honestly. Probably move main branch “pointer” to there, no idea how.

If you have b:main with some file and b:br1 with it, and b:br2 with it, and git doesn’t store patches, only files, then when you change b:main/file, then change and merge+resolve b:br1/file, then merge that into b:br2 to make it up-to-date, will these changes, when merged back to already changed b:main become conflicted? Iow, where does git keep track of 3-way diff base for back-and-forth reactualization merges? How does rebase know that? Does it? I have no idea. Better make a copy and /usr/bin/diff [—ignore-pattern] the trees afterwards to make sure the changes were correct.

As demonstrated, knowing the base abstractions doesn’t make you know how to do things in git.

I don’t even disagree, just wanted to say fuck git, I guess. Read guides or not, google or reason, you’re screwed either way.