Add Setting Filetype With Modelines as a vim til

Author: jbranchaud

README.md

@@ -7,7 +7,7 @@ variety of languages and technologies. These are things that don't really
 warrant a full blog post. These are mostly things I learn by pairing with
 smart people at [Hashrocket](http://hashrocket.com/).
 
-_433 TILs and counting..._
+_434 TILs and counting..._
 
 ---
 
@@ -496,6 +496,7 @@ _433 TILs and counting..._
 - [Searching For Hex Digits](vim/searching-for-hex-digits.md)
 - [Set End Of Line Markers](vim/set-end-of-line-markers.md)
 - [Set Your Color Scheme](vim/set-your-color-scheme.md)
+- [Setting Filetype With Modelines](vim/setting-filetype-with-modelines.md)
 - [Show All Syntax Highlighting Rules](vim/show-all-syntax-highlighting-rules.md)
 - [Split Different](vim/split-different.md)
 - [Splitting For New Files](vim/splitting-for-new-files.md)

vim/setting-filetype-with-modelines.md

@@ -0,0 +1,25 @@
+# Setting Filetype With Modelines
+
+Vim and various plugins generally use known file extensions to determine the
+filetype of a file. This is important because it is how Vim decides which
+filetype-specific settings to enable, such as syntax highlighting.
+
+If I am editing a file such as `build.boot`, Vim is not going to know that
+its filetype should be set to `clojure`. The `build.boot` file is full of
+clojure code though, so I'm losing out on syntax highlighting and so forth.
+I can settle for manually setting the filetype to clojure (e.g. `:set
+ft=clojure`) each time I open up the file.
+
+Or I can use a modeline setting. By including a comment at the top or
+bottom of the file specifying the filetype setting, I can ensure that each
+time I go to edit the file, the appropriate filetype will be set.
+
+That modeline comment will look something like:
+
+```clojure
+; vim: set ft=clojure:
+```
+
+See `:h modeline` for more details.
+
+h/t Brian Dunn