Add Sum A Bunch Of Numbers In The Current File as a Vim TIL

Author: jbranchaud

README.md

@@ -10,7 +10,7 @@ pairing with smart people at Hashrocket.
 
 For a steady stream of TILs, [sign up for my newsletter](https://crafty-builder-6996.ck.page/e169c61186).
 
-_1356 TILs and counting..._
+_1357 TILs and counting..._
 
 ---
 
@@ -1529,6 +1529,7 @@ _1356 TILs and counting..._
 - [Split The Current Window](vim/split-the-current-window.md)
 - [Splitting For New Files](vim/splitting-for-new-files.md)
 - [Source Original vimrc When Using Neovim](vim/source-original-vimrc-when-using-neovim.md)
+- [Sum A Bunch Of Numbers In The Current File](vim/sum-a-bunch-of-numbers-in-the-current-file.md)
 - [Swap Occurrences Of Two Words](vim/swap-occurrences-of-two-words.md)
 - [Swapping Split Windows](vim/swapping-split-windows.md)
 - [Swap The Position Of Two Split Windows](vim/swap-the-position-of-two-split-windows.md)

vim/sum-a-bunch-of-numbers-in-the-current-file.md

@@ -0,0 +1,35 @@
+# Sum A Bunch Of Numbers In The Current File
+
+Let's say I have a bunch of big numbers on consecutive lines in the file I
+currently have open in Vim. Like this:
+
+```
+   418564
+   921550
+  1180181
+  1234458
+  2706100
+ 15954945
+ 16254608
+```
+
+If I make a visual selection of those numbers and then hit `:`, it will open a
+command prompt for the beginning (`'<`) to the end (`'>`) of the visual
+selection. I can then shell out those lines to an external command by starting
+the command with `!`. The command to shell out to for this scenario is `awk`
+which can sum up values from a "file" in a single line.
+
+The whole thing will look like this:
+
+```
+:'<,'>!awk '{s+=$1} END {print s}'
+```
+
+Hit enter. Then `awk` will produce the sum and replace the highlighted lines
+with that value.
+
+```
+38670406
+```
+
+[source](https://stackoverflow.com/a/450821)