Add Exclude A File From A Diff Output as a git til

README.md

@@ -9,7 +9,7 @@ and pairing with smart people at Hashrocket.
 
 For a steady stream of TILs, [sign up for my newsletter](https://tinyletter.com/jbranchaud).
 
-_954 TILs and counting..._
+_955 TILs and counting..._
 
 ---
 
@@ -219,6 +219,7 @@ _954 TILs and counting..._
 - [Diffing With Patience](git/diffing-with-patience.md)
 - [Dropping Commits With Git Rebase](git/dropping-commits-with-git-rebase.md)
 - [Dry Runs in Git](git/dry-runs-in-git.md)
+- [Exclude A File From A Diff Output](git/exclude-a-file-from-a-diff-output.md)
 - [Excluding Files Locally](git/excluding-files-locally.md)
 - [Find The Date That A File Was Added To The Repo](git/find-the-date-that-a-file-was-added-to-the-repo.md)
 - [Find The Initial Commit](git/find-the-initial-commit.md)

git/exclude-a-file-from-a-diff-output.md

@@ -0,0 +1,29 @@
+# Exclude A File From A Diff Output
+
+When running `git diff <SHA>`, you'll see output for all files changed at that
+commit. It's the same if you do a range of commits (e.g. `git diff
+<SHA1>...<SHA2>`).
+
+If you are looking for changes in a particular part of the tree, then other
+changes will be a distraction. Some generated files, such as `yarn.lock`, can
+create a lot of noise in the diff output.
+
+You can get a more focused output by excluding certain files and paths. The
+syntax for doing that, however, is a bit wonky.
+
+To exclude a file, you have to add an argument formatted like
+`':(exclude)<filename>`.
+
+For instance, to exclude `yarn.lock`:
+
+```bash
+$ git diff <SHA> -- . ':(exclude)yarn.lock'
+```
+
+or to exclude an entire directory:
+
+```bash
+$ git diff <SHA> -- . ':(exclude)spec/**'
+```
+
+[source](https://stackoverflow.com/questions/39931781/git-diff-stat-exclude-certain-files/39937070#39937070)