C++ 条件编译 不同系统

#if defined (_WIN32)
    //***
#else //linux
    //***
#endif

 

C++:编写跨平台程序的关键，C/C++中的内置宏定义
分两部分：
 
操作系统判定：
Windows:   WIN32
Linux:   linux
Solaris:   __sun
 
编译器判定：
VC:  _MSC_VER
GCC/G++:   __GNUC__
SunCC:   __SUNPRO_C和__SUNPRO_CC#include <stdio.h> 

#include <iostream>
using namespace std;
int main(int argc,char **argv)
{
    int no_os_flag=1;
 
    #ifdef linux
       no_os_flag=0;
       cout<<"It is in Linux OS!"<<endl;
    #endif


    #ifdef _UNIX
       no_os_flag=0;
       cout<<"It is in UNIX OS!"<<endl;
    #endif


    #ifdef __WINDOWS_
       no_os_flag=0;
       cout<<"It is in Windows OS!"<<endl;
    #endif


    #ifdef _WIN32
       no_os_flag=0;
       cout<<"It is in WIN32 OS!"<<endl;
    #endif


    if(1==no_os_flag){
 
        cout<<"No OS Defined ,I do not know what the os is!"<<endl;
    }
    return 0;
}