syntax on
set background=dark
set shiftwidth=2
set tabstop=2
if has("autocmd")
filetype plugin indent on
endif
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 hidden " Hide buffers when they are abandoned
从 stackoverflow上找的，那上面谈论这个vimrc的人还挺多的。
先从最简单的开始慢慢加。
2011年9月28日星期三
re: An open letter to those who want to start programming
An open letter to those who want to start programming
First off, welcome to the fraternity. There aren’t too many people who want to create stuff and solve problems. You are a hacker. You are one of those who wants to do something interesting.
“When you don’t create things, you become defined by your tastes rather than ability."
– WhyTheLuckyStiff
Take the words below with a pinch of salt. All these come from me – a bag-and-tag programmer. I love to get things working, rather than sit at something and over-optimize it.
Start creating something just for fun. That’s a great start! There’s no way you will start if you say you “need to learn before doing”. Everybody’s got to start somewhere. Fire up your editor and start writing code.
Here’s something important which people might call bad advice, but I’m sure you’ll stand by me when I’m finished saying why. Initially, screw the algorithms and data structures. They do not have generic use-cases in most simple applications. You can learn them later when you need them. Over a period of time, you’ll know what to apply in situations. Knowing their names and what they do would suffice to be able to pick some paper, dust it and implement it. And that is… if no library (other programmers' re-usable code) is available, to do it in the programming language of your choice.
Choose a good language. One that you think you can produce something useful in short time.
So let C not be your first language. That might give you the satisfaction of doing things the really old-n-geeky way. C was the solution to the problem Assembly Language was. It offers better syntactic sugar than it’s prominent predecessor – Assemble Language. But today, C (or C++) is not a language that you can produce something very quickly. I would suggest that you use a dynamic language – I won’t sideline any options. Choose a language whose syntax (and documentation) you think you might be comfortable with. For this, you might want to spend some time trying out different languages for a few hours. The purpose of choosing such a language is not to make you feel better and that programming is easy. Completing stuff faster and being able to see the output keeps you motivated. Don’t choose a language that requires a special heavy-weight IDE (tool that helps you write code and run it) to program better in the language. All you should need is a text editor.
Choose a good editor.
An editor is to a programmer, like how a bow is to an archer. Here are some editors to get started with…
- SublimeText 2 – recommended if you are just starting.
- Emacs – huge learning curve. Complex key shortcuts. And to be able to customize it, you’ll need to learn Emacs Lisp.
- Vim – used by many for it’s simplicity and the fact that it comes with linux distros by default. I used Emacs for 2yrs and then switched to Vim to run away from emacs’s complex key strokes and when my little finger on both hands started hurting. Knowing vim keystrokes is a must. When you work remotely and try to type out code on some server from your computer, you’ll know that the only editor available from the command line without any installs, is Vim.
Watchout! Emacs and Vim might be really old. But they both have some features which even most modern editors don’t have.
Use an operating system that’ll teach you something.
Windows won’t teach you anything. The only thing you learn using Windows is to click the .exe file to install the software and use it. It may seem cool in the beginning, but in the long run when you have to deploy applications, especially if you are aspiring to be a web developer, you’ll need atleast basic knowledge of linux. Linux also allows you to customize stuff the way you need them to be. Macs are cool too, but I assume that you cannot afford one of those now.
Don’t copy-paste files to backup stuff.
It’s usual among amateur programmers to copy-paste files to some temporary directory in order to backup them. That’s the only way they seem to know. Stop that! Use a version control software. I strongly suggest Git, since it’s popular and easy to use. It has nice community and resources to support new-comers. (Apart from Git, There’s mercurial, darcs, fossil, etc. But just start with Git. I’m not going to bother you with the reasons for suggesting Git).
Know where to get help.
Join a community that you can relate to (with the tools you use). StackOverflow is Facebook for programmers. There are no status messages and comments. Instead there are questions and answers. Also learn to use the IRC. It’s an old form of chatrooms and is now being used by mostly developers to share information and helping each other.
Develop your netiquette.
Know when to ask questions. Most problems you face might have been stumbled upon by others who might have already posted on the internet for answers. Before asking on IRC or any forums, google first (or should I say blekko first) to see if there’s already a solution to your problem. IRC needs patience. Remember people are helping you for free out of goodwill. Sometimes it might take hours, for someone in the chatroom to respond to you. So wait until they do. Besides, be polite. It's a small world. Karma, good or bad, comes back.
Meet people, because books only teach you routine stuff (oh and the "book" is dead they say).
There are some street smarts that you’ll learn when you tinker with stuff or learn from those who do it. Roam, meet people and say hello. You are not the only programmer in your place. Make friends and do stuff with them. If you've noticed, when a couple geeks get together, whatever the starting point of the conversation be, it always ends up getting technical. It's bound to happen. Enjoy it. Programming for a good number of years, I can tell you that I learnt nothing more than what the books and articles said, until I starting meeting people and getting technical with them 6yrs back. So I always say that I’ve been programming for 6yrs, because that’s when I started meeting people and feel I really started to learn.
Write opensource code.
Writing opensource code is giving back. It’s much more than charity. You are leaving code that others can use and improve on (maybe) for years to come. It also helps you refine your skills when someone else adds to your code or suggests changes. Code that you opensource doesn't have to be big. It can even be a useful little program that downloads youtube videos. Moreover, you’ll be surprised, that your code will often help you start and have interesting conversations with people.
Lastly, when years pass, return this favour, by writing a similar letter to someone else who asks you for such help. And possibily correct me.
--
For a hacker, by a hacker
Akash Manohar
P.S: Wise men say, it takes 10 years or 10000 hours to get good at something. So don’t hurry.
2011年9月24日星期六
你真的需要重构软件吗？
Joel on Software
Things You Should Never Do, Part I
by Joel Spolsky
Thursday, April 06, 2000
Netscape 6.0 is finally going into its first public beta. There never was a version 5.0. The last major release, version 4.0, was released almost three years ago. Three years is an awfully long time in the Internet world. During this time, Netscape sat by, helplessly, as their market share plummeted.
It's a bit smarmy of me to criticize them for waiting so long between releases. They didn't do it on purpose, now, did they?
Well, yes. They did. They did it by making the single worst strategic mistake that any software company can make:
They decided to rewrite the code from scratch.
Netscape wasn't the first company to make this mistake. Borland made the same mistake when they bought Arago and tried to make it into dBase for Windows, a doomed project that took so long that Microsoft Access ate their lunch, then they made it again in rewriting Quattro Pro from scratch and astonishing people with how few features it had. Microsoft almost made the same mistake, trying to rewrite Word for Windows from scratch in a doomed project called Pyramid which was shut down, thrown away, and swept under the rug. Lucky for Microsoft, they had never stopped working on the old code base, so they had something to ship, making it merely a financial disaster, not a strategic one.
We're programmers. Programmers are, in their hearts, architects, and the first thing they want to do when they get to a site is to bulldoze the place flat and build something grand. We're not excited by incremental renovation: tinkering, improving, planting flower beds.
There's a subtle reason that programmers always want to throw away the code and start over. The reason is that they think the old code is a mess. And here is the interesting observation: they are probably wrong. The reason that they think the old code is a mess is because of a cardinal, fundamental law of programming:
It’s harder to read code than to write it.
This is why code reuse is so hard. This is why everybody on your team has a different function they like to use for splitting strings into arrays of strings. They write their own function because it's easier and more fun than figuring out how the old function works.
As a corollary of this axiom, you can ask almost any programmer today about the code they are working on. "It's a big hairy mess," they will tell you. "I'd like nothing better than to throw it out and start over."
Why is it a mess?
"Well," they say, "look at this function. It is two pages long! None of this stuff belongs in there! I don't know what half of these API calls are for."
Before Borland's new spreadsheet for Windows shipped, Philippe Kahn, the colorful founder of Borland, was quoted a lot in the press bragging about how Quattro Pro would be much better than Microsoft Excel, because it was written from scratch. All new source code! As if source code rusted.
The idea that new code is better than old is patently absurd. Old code has been used. It has been tested. Lots of bugs have been found, and they've been fixed. There's nothing wrong with it. It doesn't acquire bugs just by sitting around on your hard drive. Au contraire, baby! Is software supposed to be like an old Dodge Dart, that rusts just sitting in the garage? Is software like a teddy bear that's kind of gross if it's not made out of all new material?
Back to that two page function. Yes, I know, it's just a simple function to display a window, but it has grown little hairs and stuff on it and nobody knows why. Well, I'll tell you why: those are bug fixes. One of them fixes that bug that Nancy had when she tried to install the thing on a computer that didn't have Internet Explorer. Another one fixes that bug that occurs in low memory conditions. Another one fixes that bug that occurred when the file is on a floppy disk and the user yanks out the disk in the middle. That LoadLibrary call is ugly but it makes the code work on old versions of Windows 95.
Each of these bugs took weeks of real-world usage before they were found. The programmer might have spent a couple of days reproducing the bug in the lab and fixing it. If it's like a lot of bugs, the fix might be one line of code, or it might even be a couple of characters, but a lot of work and time went into those two characters.
When you throw away code and start from scratch, you are throwing away all that knowledge. All those collected bug fixes. Years of programming work.
You are throwing away your market leadership. You are giving a gift of two or three years to your competitors, and believe me, that is a long time in software years.
You are putting yourself in an extremely dangerous position where you will be shipping an old version of the code for several years, completely unable to make any strategic changes or react to new features that the market demands, because you don't have shippable code. You might as well just close for business for the duration.
You are wasting an outlandish amount of money writing code that already exists.
Is there an alternative? The consensus seems to be that the old Netscape code base was really bad. Well, it might have been bad, but, you know what? It worked pretty darn well on an awful lot of real world computer systems.
When programmers say that their code is a holy mess (as they always do), there are three kinds of things that are wrong with it.
First, there are architectural problems. The code is not factored correctly. The networking code is popping up its own dialog boxes from the middle of nowhere; this should have been handled in the UI code. These problems can be solved, one at a time, by carefully moving code, refactoring, changing interfaces. They can be done by one programmer working carefully and checking in his changes all at once, so that nobody else is disrupted. Even fairly major architectural changes can be done without throwing away the code. On the Juno project we spent several months rearchitecting at one point: just moving things around, cleaning them up, creating base classes that made sense, and creating sharp interfaces between the modules. But we did it carefully, with our existing code base, and we didn't introduce new bugs or throw away working code.
A second reason programmers think that their code is a mess is that it is inefficient. The rendering code in Netscape was rumored to be slow. But this only affects a small part of the project, which you can optimize or even rewrite. You don't have to rewrite the whole thing. When optimizing for speed, 1% of the work gets you 99% of the bang.
Third, the code may be doggone ugly. One project I worked on actually had a data type called a FuckedString. Another project had started out using the convention of starting member variables with an underscore, but later switched to the more standard "m_". So half the functions started with "_" and half with "m_", which looked ugly. Frankly, this is the kind of thing you solve in five minutes with a macro in Emacs, not by starting from scratch.
It's important to remember that when you start from scratch there is absolutely no reason to believe that you are going to do a better job than you did the first time. First of all, you probably don't even have the same programming team that worked on version one, so you don't actually have "more experience". You're just going to make most of the old mistakes again, and introduce some new problems that weren't in the original version.
The old mantra build one to throw away is dangerous when applied to large scale commercial applications. If you are writing code experimentally, you may want to rip up the function you wrote last week when you think of a better algorithm. That's fine. You may want to refactor a class to make it easier to use. That's fine, too. But throwing away the whole program is a dangerous folly, and if Netscape actually had some adult supervision with software industry experience, they might not have shot themselves in the foot so badly.
原址
Things You Should Never Do, Part I
by Joel Spolsky
Thursday, April 06, 2000
Netscape 6.0 is finally going into its first public beta. There never was a version 5.0. The last major release, version 4.0, was released almost three years ago. Three years is an awfully long time in the Internet world. During this time, Netscape sat by, helplessly, as their market share plummeted.
It's a bit smarmy of me to criticize them for waiting so long between releases. They didn't do it on purpose, now, did they?
Well, yes. They did. They did it by making the single worst strategic mistake that any software company can make:
They decided to rewrite the code from scratch.
Netscape wasn't the first company to make this mistake. Borland made the same mistake when they bought Arago and tried to make it into dBase for Windows, a doomed project that took so long that Microsoft Access ate their lunch, then they made it again in rewriting Quattro Pro from scratch and astonishing people with how few features it had. Microsoft almost made the same mistake, trying to rewrite Word for Windows from scratch in a doomed project called Pyramid which was shut down, thrown away, and swept under the rug. Lucky for Microsoft, they had never stopped working on the old code base, so they had something to ship, making it merely a financial disaster, not a strategic one.
We're programmers. Programmers are, in their hearts, architects, and the first thing they want to do when they get to a site is to bulldoze the place flat and build something grand. We're not excited by incremental renovation: tinkering, improving, planting flower beds.
There's a subtle reason that programmers always want to throw away the code and start over. The reason is that they think the old code is a mess. And here is the interesting observation: they are probably wrong. The reason that they think the old code is a mess is because of a cardinal, fundamental law of programming:
It’s harder to read code than to write it.
This is why code reuse is so hard. This is why everybody on your team has a different function they like to use for splitting strings into arrays of strings. They write their own function because it's easier and more fun than figuring out how the old function works.
As a corollary of this axiom, you can ask almost any programmer today about the code they are working on. "It's a big hairy mess," they will tell you. "I'd like nothing better than to throw it out and start over."
Why is it a mess?
"Well," they say, "look at this function. It is two pages long! None of this stuff belongs in there! I don't know what half of these API calls are for."
Before Borland's new spreadsheet for Windows shipped, Philippe Kahn, the colorful founder of Borland, was quoted a lot in the press bragging about how Quattro Pro would be much better than Microsoft Excel, because it was written from scratch. All new source code! As if source code rusted.
The idea that new code is better than old is patently absurd. Old code has been used. It has been tested. Lots of bugs have been found, and they've been fixed. There's nothing wrong with it. It doesn't acquire bugs just by sitting around on your hard drive. Au contraire, baby! Is software supposed to be like an old Dodge Dart, that rusts just sitting in the garage? Is software like a teddy bear that's kind of gross if it's not made out of all new material?
Back to that two page function. Yes, I know, it's just a simple function to display a window, but it has grown little hairs and stuff on it and nobody knows why. Well, I'll tell you why: those are bug fixes. One of them fixes that bug that Nancy had when she tried to install the thing on a computer that didn't have Internet Explorer. Another one fixes that bug that occurs in low memory conditions. Another one fixes that bug that occurred when the file is on a floppy disk and the user yanks out the disk in the middle. That LoadLibrary call is ugly but it makes the code work on old versions of Windows 95.
Each of these bugs took weeks of real-world usage before they were found. The programmer might have spent a couple of days reproducing the bug in the lab and fixing it. If it's like a lot of bugs, the fix might be one line of code, or it might even be a couple of characters, but a lot of work and time went into those two characters.
When you throw away code and start from scratch, you are throwing away all that knowledge. All those collected bug fixes. Years of programming work.
You are throwing away your market leadership. You are giving a gift of two or three years to your competitors, and believe me, that is a long time in software years.
You are putting yourself in an extremely dangerous position where you will be shipping an old version of the code for several years, completely unable to make any strategic changes or react to new features that the market demands, because you don't have shippable code. You might as well just close for business for the duration.
You are wasting an outlandish amount of money writing code that already exists.
Is there an alternative? The consensus seems to be that the old Netscape code base was really bad. Well, it might have been bad, but, you know what? It worked pretty darn well on an awful lot of real world computer systems.
When programmers say that their code is a holy mess (as they always do), there are three kinds of things that are wrong with it.
First, there are architectural problems. The code is not factored correctly. The networking code is popping up its own dialog boxes from the middle of nowhere; this should have been handled in the UI code. These problems can be solved, one at a time, by carefully moving code, refactoring, changing interfaces. They can be done by one programmer working carefully and checking in his changes all at once, so that nobody else is disrupted. Even fairly major architectural changes can be done without throwing away the code. On the Juno project we spent several months rearchitecting at one point: just moving things around, cleaning them up, creating base classes that made sense, and creating sharp interfaces between the modules. But we did it carefully, with our existing code base, and we didn't introduce new bugs or throw away working code.
A second reason programmers think that their code is a mess is that it is inefficient. The rendering code in Netscape was rumored to be slow. But this only affects a small part of the project, which you can optimize or even rewrite. You don't have to rewrite the whole thing. When optimizing for speed, 1% of the work gets you 99% of the bang.
Third, the code may be doggone ugly. One project I worked on actually had a data type called a FuckedString. Another project had started out using the convention of starting member variables with an underscore, but later switched to the more standard "m_". So half the functions started with "_" and half with "m_", which looked ugly. Frankly, this is the kind of thing you solve in five minutes with a macro in Emacs, not by starting from scratch.
It's important to remember that when you start from scratch there is absolutely no reason to believe that you are going to do a better job than you did the first time. First of all, you probably don't even have the same programming team that worked on version one, so you don't actually have "more experience". You're just going to make most of the old mistakes again, and introduce some new problems that weren't in the original version.
The old mantra build one to throw away is dangerous when applied to large scale commercial applications. If you are writing code experimentally, you may want to rip up the function you wrote last week when you think of a better algorithm. That's fine. You may want to refactor a class to make it easier to use. That's fine, too. But throwing away the whole program is a dangerous folly, and if Netscape actually had some adult supervision with software industry experience, they might not have shot themselves in the foot so badly.
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