Add List Available File Types as an ack til

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/).
 
-_515 TILs and counting..._
+_516 TILs and counting..._
 
 ---
 
@@ -39,6 +39,7 @@ _515 TILs and counting..._
 ### Ack
 
 - [ack --bar](ack/ack-bar.md)
+- [List Available File Types](ack/list-available-file-types.md)
 
 ### Chrome
 

ack/list-available-file-types.md

@@ -0,0 +1,31 @@
+# List Available File Types
+
+The `ack` utility allows you to filter the searched files based on file
+type. If you'd like to know all of the file types available, you can use the
+`--help=types` flag. This will include file types you've specified in your
+`.ackrc` file.
+
+Here is a sample of some of the output.
+
+```
+$ ack --help=types
+    ...
+    --[no]css          .css .less .scss
+    --[no]dart         .dart
+    --[no]delphi       .pas .int .dfm .nfm .dof .dpk .dproj .groupproj .bdsgroup .bdsproj
+    --[no]elisp        .el
+    --[no]elixir       .ex .exs
+    --[no]erlang       .erl .hrl
+    --[no]fortran      .f .f77 .f90 .f95 .f03 .for .ftn .fpp
+    --[no]go           .go
+    --[no]groovy       .groovy .gtmpl .gpp .grunit .gradle
+    --[no]haskell      .hs .lhs
+    --[no]hh           .h
+    --[no]html         .html .mustache .handlebars .tmpl
+    --[no]jade         .jade
+    --[no]java         .java .properties
+    --[no]js           .js
+    ...
+```
+
+See `man ack` for more details.