获取机器的IP地址 [英] Get the IP address of the machine

问题描述

此问题几乎与先前询问的获取IP地址相同本地计算机 - 问题。但是，我需要找到 Linux Machine 的IP地址。

所以：我如何 - - 检测我的应用程序运行的linux服务器的IP地址。服务器将至少有两个IP地址，我需要一个特定的网络（公共网络中的一个）。

我确定有

为了使事情更清楚， b

• 服务器显然会有localhost：127.0.0.1


• 服务器将有一个内部：172.16.xx


• 服务器将有一个外部（公共）IP地址：80.190.xx

我需要找到外部IP地址来绑定我的应用程序。显然，我也可以绑定到INADDR_ANY（这实际上是我现在做的）。

解决方案

我发现ioctl解决方案在os x上有问题（这是POSIX兼容所以应该类似​​于linux）。但是getifaddress（）会让你很容易做同样的事情，它对我在os x 10.5和下面应该是一样的。

我做了一个快速下面的例子将打印所有的机器的IPv4地址，（你也应该检查getifaddrs是否成功，即返回0）。

我更新了显示IPv6地址。

  #include< stdio.h> 
 #include< sys / types.h> 
 #include< ifaddrs.h> 
 #include< netinet / in.h> 
 #include< string.h> 
 #include< arpa / inet.h> 
 
 int main（int argc，const char * argv []）{
 struct ifaddrs * ifAddrStruct = NULL; 
 struct ifaddrs * ifa = NULL; 
 void * tmpAddrPtr = NULL; 
 
 getifaddrs（& ifAddrStruct）; 
 
 for（ifa = ifAddrStruct; ifa！= NULL; ifa = ifa-> ifa_next）{
 if（！ifa-> ifa_addr）{
 continue; 
} 
 if（ifa-> ifa_addr-> sa_family == AF_INET）{//检查是IP4 
 //是有效的IP4地址
 tmpAddrPtr =& （（struct sockaddr_in *）ifa-> ifa_addr） - > sin_addr; 
 char addressBuffer [INET_ADDRSTRLEN]; 
 inet_ntop（AF_INET，tmpAddrPtr，addressBuffer，INET_ADDRSTRLEN）; 
 printf（％s IP地址％s\\\
，ifa-> ifa_name，addressBuffer）; 
} else if（ifa-> ifa_addr-> sa_family == AF_INET6）{//检查它是IP6 
 //是一个有效的IP6地址
 tmpAddrPtr =& sockaddr_in6 *）ifa-> ifa_addr） - > sin6_addr; 
 char addressBuffer [INET6_ADDRSTRLEN]; 
 inet_ntop（AF_INET6，tmpAddrPtr，addressBuffer，INET6_ADDRSTRLEN）; 
 printf（％s IP地址％s\\\
，ifa-> ifa_name，addressBuffer）; 
} 
} 
 if（ifAddrStruct！= NULL）freeifaddrs（ifAddrStruct）; 
 return 0; 
} 
  

This Question is almost the same as the previously asked Get the IP Address of local computer-Question. However I need to find the IP address(es) of a Linux Machine.

So: How do I - programmatically in C++ - detect the IP addresses of the linux server my application is running on. The servers will have at least two IP addresses and I need a specific one (the one in a given network (the public one)).

I'm sure there is a simple function to do that - but where?

---

To make things a bit clearer:

• The server will obviously have the "localhost": 127.0.0.1
• The server will have an internal (management) IP address: 172.16.x.x
• The server will have an external (public) IP address: 80.190.x.x

I need to find the external IP address to bind my application to it. Obviously I can also bind to INADDR_ANY (and actually that's what I do at the moment). I would prefer to detect the public address, though.

解决方案

I found the ioctl solution problematic on os x (which is POSIX compliant so should be similiar to linux). However getifaddress() will let you do the same thing easily, it works fine for me on os x 10.5 and should be the same below.

I've done a quick example below which will print all of the machine's IPv4 address, (you should also check the getifaddrs was successful ie returns 0).

I've updated it show IPv6 addresses too.

#include <stdio.h>      
#include <sys/types.h>
#include <ifaddrs.h>
#include <netinet/in.h> 
#include <string.h> 
#include <arpa/inet.h>

int main (int argc, const char * argv[]) {
    struct ifaddrs * ifAddrStruct=NULL;
    struct ifaddrs * ifa=NULL;
    void * tmpAddrPtr=NULL;

    getifaddrs(&ifAddrStruct);

    for (ifa = ifAddrStruct; ifa != NULL; ifa = ifa->ifa_next) {
        if (!ifa->ifa_addr) {
            continue;
        }
        if (ifa->ifa_addr->sa_family == AF_INET) { // check it is IP4
            // is a valid IP4 Address
            tmpAddrPtr=&((struct sockaddr_in *)ifa->ifa_addr)->sin_addr;
            char addressBuffer[INET_ADDRSTRLEN];
            inet_ntop(AF_INET, tmpAddrPtr, addressBuffer, INET_ADDRSTRLEN);
            printf("%s IP Address %s\n", ifa->ifa_name, addressBuffer); 
        } else if (ifa->ifa_addr->sa_family == AF_INET6) { // check it is IP6
            // is a valid IP6 Address
            tmpAddrPtr=&((struct sockaddr_in6 *)ifa->ifa_addr)->sin6_addr;
            char addressBuffer[INET6_ADDRSTRLEN];
            inet_ntop(AF_INET6, tmpAddrPtr, addressBuffer, INET6_ADDRSTRLEN);
            printf("%s IP Address %s\n", ifa->ifa_name, addressBuffer); 
        } 
    }
    if (ifAddrStruct!=NULL) freeifaddrs(ifAddrStruct);
    return 0;
}

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