Linux进程间通信-基于socket,过渡到网络编程

写在前面：小生纯业余选手，开此博仅仅是为了积累，纯当笔记来用。如有看官光临小生博客，请不要相信我的代码就是正确的。如果您发现了错误也恳请耽误您一点时间，请您在下面指出来，不胜感激！

如果发现一些笔记的说法完全是错误的请建议我删除！

有基于socket的进程通信方式，这种方式可以让两个不在同一台主机上的进程进行通信

这里的通信方式与前几种有点不同，需要好好琢磨这种不同，方便以后学习网络编程。

<span style="font-size:18px;"><span style="font-family:SimSun;font-size:18px;">#include<sys/socket.h>
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<linux/un.h>
#include<unistd.h>

int main()
{
    char buf[256];
    
    int fd = socket(AF_UNIX,SOCK_DGRAM,0);
    if( fd == -1 )
    {
        printf("socket error:%m\n");
        exit(-1);
    }else
    {
        printf("socket complete\n");
    }
    
    struct sockaddr_un addr = {0};
    addr.sun_family = AF_UNIX;
    memcpy(addr.sun_path,"my.sock",strlen("my.sock"));
    
    int r = bind( fd,reinterpret_cast<struct sockaddr*>(&addr),sizeof(addr) );
    if( r == -1 )
    {
        printf("bind error:%m\n");
        exit(-1);
    }else
    {
        printf("bind complete\n");
    }
    
    while(1)
    {
        bzero(buf,sizeof(buf));
        r = read(fd,buf,sizeof(buf));
        buf[r] = '\0';
        printf("%s\n",buf);
    }
    
    close(fd);
    unlink("my.sock");
    
    return 0;
}
</span></span>
           

<span style="font-size:18px;"><span style="font-size:18px;">#include<stdio.h>
#include<stdlib.h>
#include<sys/socket.h>
#include<linux/un.h>
#include<string.h>
#include<unistd.h>

int main()
{
    char buf[256];
    
    int fd = socket(AF_UNIX,SOCK_DGRAM,0);
    
    struct sockaddr_un addr = {0};
    addr.sun_family = AF_UNIX;
    memcpy(addr.sun_path,"my.sock",strlen("my.sock"));
    int r = connect(fd,reinterpret_cast<struct sockaddr*>(&addr),sizeof(addr));

    write(fd,"come from socketB!",strlen("come from socketB!"));
    
    close(fd);
    //unlink("my.sock");
    return 0;
}
</span></span>
           

下面一个程序给上面那个程序发送数据

以下两段程序绑定的文件时一个网卡，实现不同主机间的进程的相互通信

#include<sys/socket.h>
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<netinet/in.h>
#include<arpa/inet.h>
#include<unistd.h>

int main()
{
    char buf[256];
    
    int fd = socket(AF_INET,SOCK_DGRAM,0);
    if(fd == -1 )
    {
        printf("socket error:%m\n");
        exit(-1);
    }else
    {
        printf("socket complete:%m\n");
    }
    
    struct sockaddr_in addr = {0};
    addr.sin_family = AF_INET;
    addr.sin_port = htons(8888);
    addr.sin_addr.s_addr = inet_addr("192.168.64.128");
    
    int r = bind(fd,reinterpret_cast<struct sockaddr*>(&addr),sizeof(addr));
    if(r == -1)
    {
        printf("bind error%m\n");
        exit(-1);
    }else{
        printf("bind complete\n");
    }
    
    while(1)
    {
        bzero(buf,sizeof(buf));
        r = read(fd,buf,sizeof(buf));
        buf[r] = '\0';
        printf("%s\n",buf);
    }
    
    close(fd);
    unlink("my.sock");
    return 0;
}
           

#include<sys/socket.h>
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<netinet/in.h>
#include<arpa/inet.h>
#include<unistd.h>

int main()
{    
    int fd = socket(AF_INET,SOCK_DGRAM,0);
    
    if(fd == -1 )
    {
        printf("socket error:%m\n");
        exit(-1);
    }else{
        printf("socket complete:%m\n");
    }
    
    struct sockaddr_in addr = {0};
    addr.sin_family = AF_INET;
    addr.sin_port = htons(8888);
    addr.sin_addr.s_addr = inet_addr("192.168.64.128");
    
    int r = connect(fd,reinterpret_cast<struct sockaddr*>(&addr),sizeof(addr));
    if(r == -1)
    {
        printf("bind error%m\n");
        exit(-1);
    }else{
        printf("bind complete\n");
    }
    
    write(fd,"come from ipB!",strlen("come from ipB!"));
    close(fd);
    return 0;
}
           

将以上两段程序与开始两段程序对比着看，总的来说编程的步骤是一样的，主要是结构体struct sockaddr_un{}与struct sockaddr_in{}的无别和socket()中第一个参数的区别。这也说明了基于socket的进程间的通信模型可以很好的推广到网络编程。