Git log

It’s important to get information on the state of the repository and the commits that it’s made up from in a simple, clean, and clear way. There are quite a few options that can help with this.

Useful logging

The default log can be had with the most basic invocation of git log:

git log

Personally I find this both too verbose and yet lacking in actionable information. The defaults have a tendency to be somewhat noisy, and if you know what options to add you can get much better, more focused listings from the log. A cleaner log with one entry per line tends to be more interesting for quick inspection, especially on projects with multiple small commits.

git log --oneline

# Alternatively
git log -1

If I want to know the files that have changed in each commit, this is possible too:

# for just the file names that have changed
git log --name-only

# for slightly more detail
git log --name-status

Either of these commands should give you a useful list of changed files.

git rev-list

The git-rev-list lists commits that are reachable from a commit and provides the ability to walk the commit graph. It’s the basis of many other Git commands, such as log, reflog, bisect, and so on.

What does this mean in practical terms? Not much, as in most cases you’ll use the commands that internally use rev-list. It’s good to be aware that it’s possible to access this raw data if needed, and the options that rev-list uses are also applicable to git-log.

git diff

‘git diff’ will show you the changes between the current working copy and the last commit. It can also be used to show you the difference between a whole bunch of other things, most usefully between two specific commits.

By default, it generates output in a patch format just like the ‘diff’ command. Just like the Gnu & BSD diff commands there are a lot of options, even more as it has to deal with Git as well as analysing and reporting changes.

git whatchanged

As tempting as it might be to use this as it gives a good amount of information, it’s really just a shortcut for old hacks who used Git in it’s infancy. Most should use ‘git log’ instead.

That said, I use this occasionally because it gives the names of the changed files in each commit.