Configuring Vim

It's god of editor.

apt-get install vim

vim is called 编辑器之神. You may use vim for coding or editing some files directly in OS lab environment. Maybe some of you prefer to other editors requiring GUI environment (such Visual Studio). However, you can not use them in some situations, especially when you are accessing a physically remote server:

• the remote server does not have GUI installed, or

• the network condition is so bad that you can not use any GUI tools.

Under these situations, vim is still a good choice. Another reason to choose vim is that, vim can greatly improve your coding efficiency. If you prefer to emacs, you can download and install emacs from network mirrors.

Learning Vim

You are going to be asked to modify a file using vim. For most of you, this is the first time to use vim. The operations in vim are quite different from other editors you have ever used. To learn vim, you need a tutorial. There are two ways to get tutorials:

• Issue the vimtutor command in terminal. This will launch a tutorial for vim. This way is recommended, since you can read the tutorial and practice at the same time.

• Search the Internet with keyword "vim 教程", and you will find a lot of tutorials about vim. Choose some of them to read, meanwhile you can practice with the a temporary file by

    vim test

PRACTICE IS VERY IMPORTANT. You can not learn anything by only reading the tutorials.

Some games operated with Vim

Here are some games to help you master some basic operations in vim. Have fun!

• Vim Adventures

• Vim Snake

• Open Vim Tutorials

• Vim Genius

The power of Vim

You may never consider what can be done in such a "BAD" editor. Let's see two examples.

The first example is to generate the following file:

1
2
3
.....
98
99
100

This file contains 100 lines, and each line contains a number. What will you do? In vim, this is a piece of cake. First change vim into normal state (when vim is just opened, it is in normal state), then press the following keys sequentially:

i1<ESC>q1yyp<C-a>q98@1

where <ESC> means the ESC key, and <C-a> means "Ctrl + a" here. You only press no more than 15 keys to generate this file. Is it amazing? What about a file with 1000 lines? What you do is just to press one more key:

i1<ESC>q1yyp<C-a>q998@1

The magic behind this example is recording and replaying. You initial the file with the first line. Then record the generation of the second. After that, you replay the generation for 998 times to obtain the file.

The second example is to modify a file. Suppose you have such a file:

aaaaaaaaaaaaaaaaaaaaaaaaabbbbbbbbbbbbbbbbbbbbbbbbb
cccccccccccccccccccccccccddddddddddddddddddddddddd
eeeeeeeeeeeeeeeeeeeeeeeeefffffffffffffffffffffffff
ggggggggggggggggggggggggghhhhhhhhhhhhhhhhhhhhhhhhh
iiiiiiiiiiiiiiiiiiiiiiiiijjjjjjjjjjjjjjjjjjjjjjjjj

You want to modify it into:

bbbbbbbbbbbbbbbbbbbbbbbbbaaaaaaaaaaaaaaaaaaaaaaaaa
dddddddddddddddddddddddddccccccccccccccccccccccccc
fffffffffffffffffffffffffeeeeeeeeeeeeeeeeeeeeeeeee
hhhhhhhhhhhhhhhhhhhhhhhhhggggggggggggggggggggggggg
jjjjjjjjjjjjjjjjjjjjjjjjjiiiiiiiiiiiiiiiiiiiiiiiii

What will you do? In vim, this is a piece of cake, too. First locate the cursor to first "a" in the first line. And change vim into normal state, then press the following keys sequentially:

<C-v>24l4jd$p

where <C-v> means "Ctrl + v" here. What about a file with 100 such lines? What you do is just to press one more key:

<C-v>24l99jd$p

Although these two examples are artificial, they display the powerful functionality of vim, comparing with other editors you have used.

Enabling syntax highlight

vim provides more improvements comparing with vi. But these improvements are disabled by default. Therefore, you should enable them first.

We take syntax highlight as an example to illustrate how to enable the features of vim. To do this, you should modify the vim configuration file. The file is called vimrc, and it is located under /etc/vim directory. We first make a copy of it to the home directory by cp command:

cp /etc/vim/vimrc ~/.vimrc

And switch to the home directory if you are not under it yet:

cd ~

If you use ls to list files, you will not see the .vimrc you just copied. This is because a file whose name starts with a . is a hidden file in GNU/Linux. To show hidden files, use ls with -a option:

ls -a

Then open .vimrc using vim:

vim .vimrc

After you learn some basic operations in vim (such as moving, inserting text, deleting text), you can try to modify the .vimrc file as following:

--- before modification
+++ after modification
@@ -17,3 +17,3 @@
 " Vim5 and later versions support syntax highlighting. Uncommenting the next
 " line enables syntax highlighting by default.
-"syntax on
+syntax on

We present the modification with GNU diff format. If you do not understand the diff format, please search the Internet for more information.

为什么要先上网搜索?

你或许会想, 我问别人是为了节省我的时间.

但现在是互联网时代了, 在网上你能得到各种信息: 比如 diff 格式这种标准信息, 网上是 100% 能搜到的; 就包括你遇到的问题, 很大概率也是别人在网上求助过的. 如果对于一个你本来只需要在搜索引擎上输入几个关键字就能找到解决方案的问题, 你都没有付出如此微小的努力, 而是首先想着找人来帮你解决, 占用别人宝贵的时间, 你将是这个时代的“失败者”.

于是有了 STFW (Search The F***ing Web) 的说法, 它的意思是, 在向别人求助之前自己先尝试通过正确的方式使用搜索引擎独立寻找解决方案.

正确的 STFW 方式能够增加找到解决方案的概率, 包括

• 使用 Google 搜索引擎搜索一般性问题
• 使用英文维基百科查阅概念
• 使用 Stack Overflow 问答网站搜索程序设计相关问题

如果你没有使用上述方式来 STFW, 请不要抱怨找不到解决方案而开始向别人求助, 你应该想, “噢我刚才用的是百度, 接下来我应该试试 Google”. 关于使用 Google, 在学校可以尝试设置 IPv6, 或者设置“科学上网”, 具体设置方式请 STFW.

After you are done, you should save your modification. Exit vim and open the vimrc file again, you should see the syntax highlight feature is enabled.

为什么要这么麻烦?

搞了半天, 你发现其实也就是改动一个字符而已, 干嘛不直接说清楚呢?

这是为了“入乡随俗”: 我们希望你了解怎么用计算机思维精简准确地表达我们想做的事情. diff 格式是一种描述文件改动的常用方式. 实际上, 计算机的世界里面有很多约定俗成的“规矩”, 当你慢慢去接触去了解这些规矩的时候, 你就会在不知不觉中明白计算机世界是怎么运转的.

Enabling more vim features

Modify the .vimrc file mentioned above as the following:

--- before modification
+++ after modification
@@ -21,3 +21,3 @@
 " If using a dark background within the editing area and syntax highlighting
 " turn on this option as well
-"set background=dark
+set background=dark
@@ -31,5 +31,5 @@
 " Uncomment the following to have Vim load indentation rules and plugins
 " according to the detected filetype.
-"if has("autocmd")
-"  filetype plugin indent on
-"endif
+if has("autocmd")
+  filetype plugin indent on
+endif
@@ -37,10 +37,10 @@
 " The following are commented out as they cause vim to behave a lot
 " differently from regular Vi. They are highly recommended though.
 "set showcmd            " Show (partial) command in status line.
-"set showmatch          " Show matching brackets.
-"set ignorecase         " Do case insensitive matching
-"set smartcase          " Do smart case matching
-"set incsearch          " Incremental search
+set showmatch          " Show matching brackets.
+set ignorecase         " Do case insensitive matching
+set smartcase          " Do smart case matching
+set incsearch          " Incremental search
 "set autowrite          " Automatically save before commands like :next and :make
-"set hidden             " Hide buffers when they are abandoned
+set hidden             " Hide buffers when they are abandoned
 "set mouse=a            " Enable mouse usage (all modes)

You can append the following content at the end of the .vimrc file to enable more features. Note that contents after a double quotation mark " are comments, and you do not need to include them. Of course, you can inspect every features to determine to enable or not.

setlocal noswapfile " 不要生成 swap 文件
set bufhidden=hide " 当 buffer 被丢弃的时候隐藏它
colorscheme evening " 设定配色方案
set number " 显示行号
set cursorline " 突出显示当前行
set ruler " 打开状态栏标尺
set shiftwidth=4 " 设定 << 和 >> 命令移动时的宽度为 4
set softtabstop=4 " 使得按退格键时可以一次删掉 4 个空格
set tabstop=4 " 设定 tab 长度为 4
set nobackup " 覆盖文件时不备份
set autochdir " 自动切换当前目录为当前文件所在的目录
set backupcopy=yes " 设置备份时的行为为覆盖
set hlsearch " 搜索时高亮显示被找到的文本
set noerrorbells " 关闭错误信息响铃
set novisualbell " 关闭使用可视响铃代替呼叫
set t_vb= " 置空错误铃声的终端代码
set matchtime=2 " 短暂跳转到匹配括号的时间
set magic " 设置魔术
set smartindent " 开启新行时使用智能自动缩进
set backspace=indent,eol,start " 不设定在插入状态无法用退格键和 delete 键删除回车符
set cmdheight=1 " 设定命令行的行数为 1
set laststatus=2 " 显示状态栏 (默认值为 1, 无法显示状态栏)
set statusline=\ %<%F[%1*%M%*%n%R%H]%=\ %y\ %0(%{&fileformat}\ %{&encoding}\ Ln\ %l,\ Col\ %c/%L%) " 设置在状态行显示的信息
set foldenable " 开始折叠
set foldmethod=syntax " 设置语法折叠
set foldcolumn=0 " 设置折叠区域的宽度
setlocal foldlevel=1 " 设置折叠层数为 1
nnoremap <space> @=((foldclosed(line('.')) < 0) ? 'zc' : 'zo')<CR> " 用空格键来开关折叠

提高开发效率的编辑器

程序设计课上你学会了使用 Visual Studio, 然后你可能会认为, 程序员就是这样写代码的了. 其实并不是, 程序员会追求那些提高效率的方法. 不是 GUI 不好, 而是你只是用记事本的操作方式来写代码. 所以你需要改变, 去尝试一些可以帮助你提高开发效率的工具.

在 GNU/Linux 中, 与记事本的操作方式相比, 学会vim的基本操作就已经可以大大提高开发效率. 还有各种插件来增强vim的功能, 比如可以在代码中变量跳转的ctags等等. 你可以花点时间去配置一下vim, 具体配置方式请 STFW. 总之, “编辑器之神”可不是浪得虚名的.