ruby c++
While looking for information on the subject, I looked into the ONLamp article Extending Ruby with C by Garrett Rooney, the Extending Ruby chapter in the Pickaxe, README.EXT (located at /usr/share/doc/ruby1.8-dev/README.EXT.gz on my Ubuntu system) and got some help from Kjetil.
The resulting file can be found here: wtmplist.c.
Disclaimer: I’m not resposible if you should destroy something with your newfound skills, nor am I responsible if you should suddenly get the urge to leave your wife/loved ones in favor of Ruby.
Table of Contents:
What to Extend?
How Do I Want the Interface to Be?
Get to it! #include <ruby.h>
Groundwork.
Making it Compile.
Collect the Data th Make Available.
Adding More Functionality.
Test Your New Library.
What to Extend?
Obviously you start by figuring out what you want to extend Ruby with. Some library missing, or better implemented in C? Some library you wrote yourself and want to be able to use from Ruby scripts?
I have a project coming up where I’ll have to look into /var/log/wtmp to get login entries, and didn’t find any classes/modules that made this possible in Ruby. There are documented (through Man) C functions to access the structures in the file, so I started to look at the introductions to extending Ruby (regrettably I somehow forgot about the Pickaxe at this point, but Kjetil reminded me after I had been cursing for a while).
Moving on to the next step …
How Do I Want the Interface to Be?
The point here is to think how you would like the information and methods represented in Ruby. In my case, I want to read in all entries in wtmp, and have them available in a list of some sort. In Ruby that means using the array. So an Array of entries doesn’t sound too bad. To make things cleaner, I’ll also put it in a module. This maps to this Ruby code (roughly):
module Wtmp
class List < Array
def initialize
# open wtmp
# wtmp.each_struct
相关文档：
二分查找的代码.
int bfind(int* a,int len,int val)
{
int m = len/2;
int l = 0;
int r = len;
while(l!=m && r!= m)
{
if(a[m] > val)
& ......
有些同学提问：我写数据到文件中会把老的数据替换掉。
怎么在源文件的基础上添加内容，而不是重写
【ruby code】
def txt_write(value,memo)
File.open("c:\\my_text.txt", 'a') do |f|
......
c与c++ static函数的区别
本文转自：http://blog.csdn.net/lipps/archive/2007/05/18/1615419.aspx
static关键字是C, C++中都存在的关键字, 它主要有三种使用方式, 其中前两种只指在C语言中使用, 第三种在C++中使用(C,C++中具体细微操作不尽相同, 本文以C++为准).
(1)局部静态变量
(2)外部静态变 ......
在最近的一个关于LKML的讨论中，Linus给出了为什么不用C++来写Linux内核的理由：
"In fact, in Linux we did try C++ once already, back in 1992. It sucks. Trust me - writing kernel code in C++ is a BLOODY STUPID IDEA.
“事实上，我们曾经尝试过用C++来写，是在1992年的时候。很糟糕。相信我--用C++来写内核 ......
#include < ruby.h > //
static int id_sum;
int Values[] = {5, 10 ,15,-1,20,0};
static VALUE wrap_sum(VALUE args)
{
VALUE * values = (VALUE *) args;
VALUE summer = values[0];
VALUE max = values[1];
return rb_funcall(summer,id_sum,1,max);
}
static VALUE ......
