Vim
Last updated
Last updated
You can get the slides for this workshop here:
Writing code or editing files on a computer has a lot of moving parts: you spend a lot of time switching between files, navigating and editing code compared to writing a long stream of words sometimes.
As programmers, or just general power users, we will spend a lot of time doing these things, so it is extremely beneficial to invest some time into learning an editor.
People tend to have extremely strong opinions on editors to learn. See:
For purposes of this workshop, we'll be trying to learn vim, a command line editor. Feel free to bring your experience of learning a new editor to any other editor
Within NUS, vim is the main editor you'll learn and use (you'll probably use it if you've done CS2030 within SOC). Vim is an editor with an extremely rich history. Vim is actually an acronym for VI iMproved, created by the late Bram Moolenaar in 1991, who unfortunately passed on in 2023.
As the name suggests, it was based of another text editor, vi, created by Bill Joy in 1976.
Vim is built around a bunch of cool ideas, and a lot of tools support vim emulation. It is probably really useful to learn the neat ideas of vim even if you end up using a different editor for your day to day use.
Bill Joy was trying to create an editor that was usable with a 300 baud modem. To put this into context, this is approximately 0.3 kbits/second connection, and transmitting text was often much slower than the time it took to read it. This is why vim has somewhat unintuitive commands when you first start out. Because you could type only about one letter a second, the commands had to be really, really short.
As it turns out, if you build an editor with the purpose of minimizing keystrokes, you have a really efficient editor.
The key idea behind vim is that as a power user, you spend most of the time reading, not writing. As such, vim is built to be a modal editor: it has different modes for inserting text and manipulating text. Vim itself is a programmable with Vimscript and other languages. As such, there is also a huge thriving plugin community around vim. Vim itself is also a programmable interface, keystrokes are commands and we can compose them to do complex actions. While vim does have mouse support, to efficiently use vim, we very much avoid the use of the mouse, simply because it's too slow; Vim even avoids using the arrow keys because it would take too much time to move your hands to the arrow keys.
Vim is built to be as efficient as possible
Vim itself is a programmable interface: individual keystrokes become our commands and we can combine them to do some cool stuff.
Vim tends to avoid anything that requires the movement of the hand off the homerow of the keyboard. This means less emphasis on arrow keys and the mouse, even though they still work in vim.
There are a few primary modes of vim:
Normal Mode - For moving around a file and making small edits
Insert Mode - For inserting text
Visual Mode - For selecting blocks of text
Command Mode - For entering commands
Keystrokes have very different meanings in different operating modes. For example, xin insert mode will just insert the 'x' character, but in normal mode it would delete a character.
In its default configuration, Vim shows the current mode in the bottom left. The initial/default mode is Normal mode. You’ll generally spend most of your time between Normal mode and Insert mode.
There's a common joke that if you give a web designer a computer with vim loaded up, and ask them to quit vim, you will get a random string generator. To open vim, just type vimin the terminal. To quit, just type :q. This might seem unintuitive at first, but we'll explain it as we go along.
If you're confused why vim is built this way, remember that the whole philosophy of vim is doing things with as little keystrokes as possible.
Command mode is where we run commands similar to a command line in vim. To go to this mode, simple press : . A text bar should appear at the bottom of the screen. From there, we can execute several vim commands.
: - go to command mode
q (in command mode) - quits the file
w (in command mode) - saves the file
! - force an action
:wq - save the file then quit
:q! - force quit file without saving
Once you are done, vim should automatically put you back in normal mode
Normal mode is your default mode where you should spend most of your time. In vim, if you ever get lost or are not sure what is happening, always reset to normal mode Esc will bring you to normal mode from any of the other modes. You will be using this a lot.
It might seem quite counterintuitive to use escape since it’s quite out of place on your keyboard. However, vi was created using an ADM-3A terminal. It looks like this:
Notice where the Esckey is?
You will use the Esckey a lot when using vim. Consider remapping your Caps Lock:
If you're using Linux, you'll figure it out ;)
First let’s open up a file using vim by using vim (filename). We can navigate the file by using hjkl (left, down, up, right respectively) Why not arrow keys (or a mouse)? Historically, it’s because the old keyboards did not have arrow keys or a mouse. However, in practice, it is extremely efficient as you don’t need to move you hands away from the alphanumeric keys to do anything.
Here are more movement options in Normal mode:
Basic
hjkl: left, down, up, right
Word
w: next word, b: back a word
File
gg: go to top of file, G: go to bottom of file
Line
0: beginning of line, $: end of line, ^: first non-whitespace of line
Line Numbers
34G: Go to line 34
Screen
H: igh part of screen, M:iddle of screen, L:ow part of screen
Braces
%: go to corresponding braces
Repeating
10j: to go down 10 times
Scroll
Ctrl + d: scroll down, Ctrl + u: scroll up
Find (inline)
f: to find further up the line, F: to find everything before the cursor, ,/;: to navigate between results
Search (file)
/ + query: to search forward from the cursor, ?to search backwards from the cursor
Open a text file using the command vim file. It could be any piece of text. Try navigating around the file with the above commands!
Make sure you are in normal mode. Esc
i to insert before cursor
I to insert at the start of line
a to insert after cursor
A to insert at the end of line
o to start a next line and insert
O to start a line above the current selection and insert
Get out of insert once done. Esc
In normal word, you can quickly delete a portion of text:
d + modifier, deletes a certain portion based on the modifier
dw – delete word
6dw – delete 6 words
dd – delete the entire line
d$ – delete till end of line
dt + char – delete till character
Similarly, change allows you to quickly delete and change a certain portion of text:
c + modifier – deletes then puts you into insert mode
cw – change word
7cw – change 7 words
c$ – change till end of line
ct + char – change till certain character
In normal mode, yank (y) copies text into a buffer (think of Ctrl + C). The following commands are variations:
yy – yank the entire line
yw – yank a single word
6yw – yank 6 words
yt + char – yank till (but not including) a certain character
p – put/paste whatever is in the buffer (below the current line)
P – put/paste whatever is in the buffer (above the current line)
x – delete a certain character
r – replace a character
. – repeat the last action
u – undo the previous action
Ctrl + r – redo the last undone action
You can combine nouns and verbs with a count, which will perform a given action a number of times.
3w move 3 words forward
5j move 5 lines down
7dw delete 7 words
You can use modifiers to change the meaning of a noun. Some modifiers are i, which means “inner” or “inside”, and a, which means “around”.
ci( change the contents inside the current pair of parentheses
ci[ change the contents inside the current pair of square brackets
da' delete a single-quoted string, including the surrounding single quotes
Try and fix the typos and small erros here!
There are a few kinds of visual modes:
Visual – v
Visual Line – V
Visual Block – Ctrl + v
You can use these selections along with the commands covered above:
y (yank)
d (delete)
c (change)
It seems like the data from the first two lines are corrupted, lets remove them from our data!
Aside from saving and quitting, here are a few more important commands to know:
:enew – opens a new file
:e <filepath> – open the file at the specified path
:sp – open a new horizontal split
:vsp – open a new vertical split
:sort- sort selected text
Macros are one of the really powerful features in Vim that can significantly speed up your workflow:
q + register to start recording a macro, then q again to stop recording
@<register> to apply (play back) the macro
Let’s use a macro to extract the names from these emails!
There are tons of plugins for extending Vim. Contrary to outdated advice that you might find on the internet, you do not need to use a plugin manager for Vim (since Vim 8.0).
https://github.com/amix/vimrc
https://vimconfig.com
Without giving a long, non-exhaustive list of plugins, here are some really cools ones you should try out!
These plugins not only try to speed up your vim workflows, but also add additional functionality to vim.
Many tools support Vim emulation. The quality varies from good to great; depending on the tool, it may not support the fancier Vim features, but most cover the basics pretty well.
Vim is a really powerful editor if you are able to master it. Don’t worry, there are plenty of resources!
:help <command> – get the manual for a specific command
vimtutor – built-in Vim tutor. Give it a read; it shouldn’t take more than 30 minutes
VimGolf – a really good practice site: edit the file in the fewest keystrokes
There are tons of Vim wikis, guides, and cheat sheets out there—just search for them!
This workshop was loosely based of MIT's Missing Semester of your CS Education:
