#define UNIX_PATH_MAX 108
struct sockaddr_un
{__kernel_sa_family_t sun_family; /* 通信协议 AF_UNIX / AF_LOCAL */char sun_path[UNIX_PATH_MAX]; /* pathname *///UNIX 域协议的地址,是以'\0'结束的本地文件系统中的绝对路径名//会自动的创建不需要提前创建
};

/*socketpair1.c*/
#include <sys/types.h>
#include <sys/socket.h>
#include <stdlib.h>
#include <stdio.h>
int main ()
{int sv[2];int result = socketpair(AF_UNIX, SOCK_STREAM, 0, sv);if (result < 0){exit(1);}printf("sv[0] is : %d \n", sv[0]); //这两个套节字句柄并不相同，但作用是一样的printf("sv[1] is : %d \n", sv[1]);if (fork()){ /* 父进程 */int val = 0;pid_t pid = getpid(); close(sv[1]); //父进程关闭 sv[1]的读写权限while (1){ ++val;printf("%d send message: %d\n", pid, val); write(sv[0], &val, sizeof(val)); //父进程向管道里写数据//也可以去读// read(sv[0], &val, sizeof(val)); //如果字进程不写数据，将会导致此处堵塞//printf("%d receive message: %d\n", pid, val);sleep(1);}}else{ /*子进程*/int val = 0;close(sv[0]); //字进程关闭 sv[0]的读写权限pid_t pid = getpid(); while(1){read(sv[1], &val, sizeof(val)); //字进程从管道中取数据printf("%d receive message: %d\n", pid, val);// printf("%d receive message: %d\n", pid, val); //也可以写// write(sv[1], &val, sizeof(val));}}
}

UNIX 域协议之进程间通信方式二：套接字通信方式

#include<stdio.h>
#include<stdlib.h>
#include <sys/types.h> /* See NOTES */
#include <sys/socket.h>
#include <sys/un.h>
#include <arpa/inet.h>
#include<netinet/in.h> //为了使用 IPV4 地址结构体
#include <string.h>
#include <arpa/inet.h>
#include <unistd.h>#define UNIX_PATH_PS "/home/china/sockp1" //连接的套接字地址
#define UNIX_PATH_PC "/home/china/sockp2" //绑定的套接字地址int main(int argc,char *argv[])
{system("rm /home/china/sockp2"); //防止文件重名//1.创建一个套接字int sockfd = socket(AF_UNIX, SOCK_STREAM,0); //创建一个本地通信 UNIX 流式套接字if(-1 == sockfd){perror("create socket failed");exit(-1);}//2.绑定一个通信地址(让服务器能看到我)，可不绑定struct sockaddr_un local; memset(&local,0,sizeof(struct sockaddr_un)); //清空结构体local.sun_family = AF_UNIX;strcpy(local.sun_path,UNIX_PATH_PC);int ret = bind(sockfd,(struct sockaddr*)&local,sizeof(local));if(ret == -1){perror("bind error");exit(-1);}printf("bind success\n");//连接目标服务器struct sockaddr_un saddr; //保存目标服务器的地址(本地的文件名)memset(&saddr,0,sizeof(struct sockaddr_un)); //清空结构体saddr.sun_family = AF_UNIX;strcpy(saddr.sun_path,UNIX_PATH_PS);ret = connect(sockfd, (struct sockaddr*)&saddr,sizeof(saddr)); //请求连接目标服务器if(ret == -1){perror("connect error");exit(-1);}printf("connect success\n");char buf[1024] = {0};//读取信息ret = recv(sockfd,buf,1024, 0);if(ret == -1){perror("recv error");}printf("recv size:%d,recv data:%s\n",ret,buf);//发送信息ret = sendto(sockfd,"byebye",6,0,NULL,0);if(ret == -1){perror("sendto error");}printf("sendto size:%d\n",ret);//关闭套接字shutdown(sockfd,SHUT_RDWR);close(sockfd);return 0;
}

#include<stdio.h>
#include<stdlib.h>
#include <sys/types.h> /* See NOTES */
#include <sys/socket.h>
#include <sys/un.h>
#include <arpa/inet.h>
#include<netinet/in.h> //为了使用 IPV4 地址结构体
#include <string.h>
#include <arpa/inet.h>
#include <unistd.h>
#define UNIX_PATH_PS "/home/china/sockp1"int main(int argc,char *argv[])
{system("rm /home/china/sockp1"); //保证该文件没有被使用//1.创建一个套接字int sockfd = socket(AF_UNIX, SOCK_STREAM,0); //创建一个本地通信UNIX 流式套接字if(-1 == sockfd){perror("create socket failed");exit(-1);}//2.绑定一个通信地址(作为服务器本身的地址)struct sockaddr_un local; //保存服务器的地址(文件名)memset(&local,0,sizeof(struct sockaddr_un)); //清空结构体local.sun_family = AF_UNIX;strcpy(local.sun_path,UNIX_PATH_PS);int ret = bind(sockfd,(struct sockaddr*)&local,sizeof(local)); //绑定服务器的地址if(ret == -1){perror("bind error");exit(-1);}printf("bind success\n");//3.开启对一个套接字的监听listen(sockfd,250);//4.等待客户端的连接while(1){struct sockaddr_un caddr; //保存客户端的地址(文件名)socklen_t len = sizeof(caddr);int confd = accept(sockfd,(struct sockaddr*)&caddr,&len); //阻塞等待客户端连接if(confd > 0) //客户端连接成功,返回一个连接套接字专门用来和客户端通信{//一个客户端连接成功.开一个进程/线程去处理这个连接printf("client path:%s\n",caddr.sun_path);ret = sendto(confd,"nishiliangzaima?",20,0,NULL,0); //发送消息if(ret == -1){perror("sendto error");}char buf[1024] = {0};ret = read(confd,buf,1024); //接收消息if(ret <= 0){perror("recv error");}printf("recv size:%d,recv data:%s\n",ret,buf);close(confd);//关闭连接套接字}}//关闭套接字shutdown(sockfd,SHUT_RDWR);close(sockfd);return 0;
}