Open Vim and split files

When Vim is open already, you can open another file in a split with :split file/path.rb or :vsplit file/path.js. But you can also open Vim from the command line with files already split:

• vim -o file1.txt file2.txt – Open both files in Vim, split horizontally
• vim -O file1.txt file2.text – Open both files in Vim, split vertically

Since the command line takes any number of arguments, you can also open multiple files with a * glob or even {} braces from your shell:

• vim -o file/path/*.rb – Open all the .rb files at the path in horizontal splits
• vim -O file/path/{one,two}.txt – Open one.txt and two.text in vertical splits

Why would you want to do this? A big reason to open specific files from the command line is to have them in your shell history. Since you can reverse autocomplete from your history with ctrl-r, having specific file names in your history allows you to quickly get back to editing the same files in a snap. (See also: Open to a pattern.)

In the video demo below, I open both the README files in the project in vertical splits with vim -O README*. Then I open all the markdown files in horizontal splits with vim -o *.md. You can see that if you use a glob that selects too many files, it can get unwieldy quickly.