Add Undo Some Command Line Editing as a unix til

README.md

@@ -10,7 +10,7 @@ smart people at [Hashrocket](http://hashrocket.com/).
 For a steady stream of TILs from a variety of rocketeers, checkout
 [til.hashrocket.com](https://til.hashrocket.com/).
 
-_525 TILs and counting..._
+_526 TILs and counting..._
 
 ---
 
@@ -497,6 +497,7 @@ _525 TILs and counting..._
 - [SSH With Port Forwarding](unix/ssh-with-port-forwarding.md)
 - [Sort In Numerical Order](unix/sort-in-numerical-order.md)
 - [Switch Versions of a Brew Formula](unix/switch-versions-of-a-brew-formula.md)
+- [Undo Some Command Line Editing](unix/undo-some-command-line-editing.md)
 - [View A Web Page In The Terminal](unix/view-a-web-page-in-the-terminal.md)
 - [Watch The Difference](unix/watch-the-difference.md)
 - [Watch This Run Repeatedly](unix/watch-this-run-repeatedly.md)

unix/undo-some-command-line-editing.md

@@ -0,0 +1,12 @@
+# Undo Some Command Line Editing
+
+When using some of the fancy command line editing shortcuts, such as
+`ctrl-u`, you may end up erroneously changing or deleting part of the
+current command. Retyping it may be a pain or impossible if you've forget
+exactly what was changed. Fortunately, bash's command line editing has undo
+built in. Just hit `ctrl-_` a couple times to get back to where you want to
+be.
+
+h/t Chris Erin
+
+[source](https://www.gnu.org/software/bash/manual/bashref.html#Command-Line-Editing)