Git is so Cool Part-2
technical, git ·If you have not already, check out the first part of this series, where I talk about adding files to the staging area.
In this post, I will talk about diff, the command that literally tells us the difference between two sets of files.
Good ol’ diff
In the context of git, the --diff option diffs the staged file (in the index) with the current file on the filesystem (clean or dirty). The point of this post isn’t to harp over how to diff between index, file system, commits or branches or what not, but to use it more effectively when a diff is not straightforward.
Very often we come across sentences with such minute difference between them, it’s hard to see what’s changed. Take for example,
A quick brown fox jupms over the lazy dog.
A quick brown fox jumps over the lazy dog.
Observe that the difference between the two lines is just the spelling of jumps. This can be tricky to find especially when you are running a line-based diff command like git diff.
Here’s what git-diff returns:
git --diff ex.txt
Hardly useful given the text. It would take a trained eye to figure out the difference between the lines. There has to be a better way.
Finer diff
The problem here is that diff is taking a line as a unit to run diff. What if we could instruct diff to take a finer unit. A word seems a good option. After all it is easier to sift through a few letters of a given word compared to a few words of a potentially large line. This is where --word-diff option comes into the scene. Passed alongside the --diff option to git, it runs diff with a word as it’s unit.
Here’s what it looks like:
git --diff --word-diff ex.txt
Much Finer diff
This is already much better, but what if we want to provide our own definition of a word, the unit of diff. In Computer Science, very few techniques let us succinctly express pattern like regex. It’s only natural that our target unit of diff be passed along as a regex. Indeed, git has a --word-diff-regex=<regex> option that can be passed along side --diff.
Lets look at the finest grain of seperation, a character. In regex lingo, this is simply the regex ..
Putting it all together:
git --diff --word-diff-regex='.' ex.txt
Hope this post eases your workflow. I will be sharing more interesting (hopefully) stories and posts here on Coding Memoirs. Keep an eye out!
Au Revoir