Avoid destroying record of last visual selection
author |
Daniel Robert Allen <allen.daniel.r@gmail.com> |
date |
Sun, 07 Apr 2013 11:33:46 -0700 |
parents |
b0ca11bfb7a8 |
children |
92fa86978feb |
Echoing Messages
================
The first pieces of Vimscript we'll look at are the `echo` and `echom` commands.
You can read their full documentation by running `:help echo` and `:help echom`
in Vim. As you go through this book you should try to read the `:help` for
every new command you encounter to learn more about them.
Try out `echo` by running the following command:
:::vim
:echo "Hello, world!"
You should see `Hello, world!` appear at the bottom of the window.
Persistent Echoing
------------------
Now try out `echom` by running the following command.
:::vim
:echom "Hello again, world!"
You should see `Hello again, world!` appear at the bottom of the window.
To see the difference between these two commands, run the following:
:::vim
:messages
You should see a list of messages. `Hello, world!` will *not* be in this list,
but `Hello again, world!` *will* be in it.
When you're writing more complicated Vimscript later in this book you may find
yourself wanting to "print some output" to help you debug problems. Plain old
`:echo` will print output, but it will often disappear by the time your script
is done. Using `:echom` will save the output and let you run `:messages` to
view it later.
Comments
--------
Before moving on, let's look at how to add comments. When you write Vimscript
code (in your `~/.vimrc` file or any other one) you can add comments with the
`"` character, like this:
:::vim
" Make space more useful
nnoremap <space> za
This doesn't *always* work (that's one of those ugly corners of Vimscript), but
in most cases it does. Later we'll talk about when it won't (and why that
happens).
Exercises
---------
Read `:help echo`.
Read `:help echom`.
Read `:help messages`.
Add a line to your `~/.vimrc` file that displays a friendly ASCII-art cat
(`>^.^<`) whenever you open Vim.