1. 关于我
个人信息
Jick Nan |
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2. Coding Style
先看 [http://lxr.linux.no/source/Documentation/CodingStyle Linux kernel coding style]
2.1. Indentation
- 8-char indent
- If you need more than 3 levels of indentation, you're screwed anyway, and should fix your program.
- Don't put multiple statements on a single line unless you have something to hide.
- Get a decent editor, and don't leave whitespace at the end of lines.
2.2. Breaking long lines and strings
- Coding style is all about readability and maintainabilty using commonly avaible tools.
- The limit on the length of lines is 80 colums and this is a hard limit.
2.3. Placing braces
- The preferred way, as shown to us by the prophets Kernighan and Ritchie, is to put the opening brace last on the line, and put the closing brace first.
- namely function have the opening brace at the begining of the next line.
2.4. Naming
- C is a Spartan language, and so should your naming be.
- GLOBAL variables (to be used only if you _really_need them) need to have descriptive name, as do global functions.
- LOCAL variable name should be short, and to the point.
2.5. Fuctions
- Fuctions should be short and sweet, and do just one thind.
- Another measure of the functions is the number of local variables, They shouldn't exceed 5-10, or you're doing something wrong.
2.6. Centralized exiting of functions
- About gogo statement.
2.7. Commenting
- Comments are good, but there is also a demage of over-commenting.
- Generally, you want your comments to tell WHAT your code does, not HOW.
2.8. You've made a mess of it
- About GNU Emacs and GNU indent.
- 'indent' is not a fix for bad programing.
2.9. Data structures
- Data structures that have visibility outside the single-threaded environment they are created and destoryed in should always have reference counts.
- Locking is _not_ a replacement for reference counting.
- If another thread can find your data structure, and you don't have a reference count on it, you almost certainly have a bug.
2.10. Macros, Enums, Inline functions and RTL
- Names of macros defining contants and labels in enums are capitalized.
- Enums are preferred when defining serval related constants.
- Generally, inline functions are preferable to macros resembling functions.
- Macros with multiple statements should be enclosed in a do-while block.
3. C
3.1. malloc, calloc, free
- 一个严重的错误：释放不是通过调用 malloc, calloc 得到的指针所指向的存储空间。
- 使用已释放空间同样是错误的。
4. Gnu Tools
4.1. Vim
先看 [http://chinaunix.net/jh/28/194152.html 进行有效编辑的七种习惯] by Bram Moolenaar, the author of vim.
再看 [http://www-128.ibm.com/developerworks/cn/linux/l-tip-vim1/ Vim 实用技术] at DeveloperWorks.
4.1.1. Edit a file
4.1.1.1. Move around quickly
If you set the incsearch option, Vim will show the first match for the pattern, while you are still typing it. This quickly shows a typo in the pattern.
If you set hlsearch option, Vim will highlight all matches for the pattern with a yellow background.
If you see a specific word and want to search for other occurrences of the same word, use the * command to grab the word from under the cursor and search for the next one, while # search for the previous one.
- In structured text(C/C++)
% can jump to many different matching items. It is very useful to check if() and {} constructs are balanced properly.
Use [{ to jump back to the "{" at the start of the current code block, and ]} for '}'.
Use gd to jump from the use of variable to its local declaration.
- 可视（visual）模式，用于选定文本块；可以在正常模式下输入“v”（小写）来按字符选定，输入“V”（大写）来按行选定，或输入“Ctrl-V”来按方块选定。
4.1.1.2. Don't type it twice
If you want to change one word into another in the whole file, you can use the :s(substitute) command.
If you want to change one word into another only a few locations, a quick method is to use the * command to find the next occurrence of the word and use cw to change the word. Then type n to find the next word and .(dot) to repeat the cw command.
CTRL-N can auto complete function and variable names. Vim looks up words in the file you are editing, and also in #include'd files.
Vim has a mechanism to record a macro. You type qa to start recording into register 'a'. Then you type your commands as usual and finally hit q again to stop recording. When you want to repeat the recorded commands you type @a.
4.1.1.3. Fix it when it's wrong
It's normal to make errors while typing, this can be corrected with abbreviations: :abbr Lunix Linux.
The same mechanism can be used to type a long word with just a few characters: :abbr pn pinguin.
- To find errors in your text Vim has a clever hightlighting mechanism. This was actually meant to be used to do syntax hightlighting of programs, but it can catch and highlight errors as well.
- A more complex example: English text.
4.1.2. Edit more files
4.1.2.1. A file seldom comes alone
- Tag mechanism works for jumping between files.
Another powerful mechanism is to find all occurrences of a name in a group of files, using the :grep command. Vim makes a list of all matches, and jumps to the first one. The :cn command takes you to each next match.
Positions the cursor on the name of the function in your file and type [i: Vim will show a list of all matches for the function name in the included files.
- In vim you can split the text erea in several parts to edit different files.
- There are more uses of multiple window. The preview-tag mechanism is a very good example.
4.1.2.2. Let's work together
Select some structured text in a list and sort it: !sort.
4.1.2.3. Text is structured
One of the simpler things is to speed up the edit-compile-fix cycle. Vim has the :make command, which starts your compilations, catches the errors it produces and lets you jump to the error locations to fix the problems.
4.1.3. Sharpen the saw
4.1.3.1. Make it a habit
- You need to learn new commands and turn them into a habit.
4.2. CVS
先看 [http://www.chedong.com/tech/cvs_card.html CVS使用手册] by Chedong.
5. 反馈
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