Add Reference A Commit Via Commit Message Pattern Matching as a git til.

Author: jbranchaud

README.md

@@ -76,6 +76,7 @@ smart people at [Hashrocket](http://hashrocket.com/).
 - [List Filenames Without The Diffs](git/list-filenames-without-the-diffs.md)
 - [List Untracked Files](git/list-untracked-files.md)
 - [Move The Latest Commit To A New Branch](git/move-the-latest-commit-to-a-new-branch.md)
+- [Reference A Commit Via Commit Message Pattern Matching](git/reference-a-commit-via-commit-message-pattern-matching.md)
 - [Renaming A Branch](git/renaming-a-branch.md)
 - [Resetting A Reset](git/resetting-a-reset.md)
 - [Single Key Presses in Interactive Mode](git/single-key-presses-in-interactive-mode.md)

git/reference-a-commit-via-commit-message-pattern-matching.md

@@ -0,0 +1,32 @@
+# Reference A Commit Via Commit Message Pattern Matching
+
+Generally when referencing a commit, you'll use the SHA or a portion of the
+SHA. For example with `git-show`:
+
+```
+$ git show cd6a63d014
+...
+```
+
+There are many ways to reference commits though. One way is via regex
+pattern matching on the commit message. For instance, if you recently had a
+commit with a typo and you had included *typo* in the commit message, then
+you could reference that commit like so:
+
+```
+$ git show :/typo
+Author: Josh Branchaud
+Date: Mon Dec 21 15:50:20 2015 -0600
+
+    Fix a typo in the documentation
+...
+```
+
+By using `:/` followed by some text, git will attempt to find the most
+recent commit whose commit message matches the text. As I alluded to, regex
+can be used in the text.
+
+See `$ man gitrevisions` for more details and other ways to reference
+commits.
+
+[Source](https://twitter.com/jamesfublo/status/678906346335428608)