unix socket 测试代码

根据网上代码http://blog.csdn.net/zchengdong/article/details/6934466 修改，具体打开的socket情况使用lsof -u username 查看，修改后的代码情况如下，可分别修改读取的s[0],s[1]查看读写情况。

#include <stdio.h> 
#include <string.h> 
#include <unistd.h> 
#include <sys/types.h> 
#include <errno.h> 
#include <errno.h> 
#include <sys/socket.h> 
#include <stdlib.h> 
 
#define BUF_SIZE 300 
 
int main()
{ 
        int s[2];  
        int w,r; 
        char string[256] = {0};
        char * buf = (char*)calloc(1 , BUF_SIZE); 
        pid_t pid; 
 
        if(socketpair(AF_UNIX,SOCK_STREAM,0,s) == -1 ){ 
             printf("create unnamed socket pair failed:%s\n",strerror(errno) ); 
             exit(-1); 
        } 
        
        if(( pid = fork()) > 0 ){ 
                printf("Parent process's pid is %d\n",getpid()); 
                //close(s[1]); 
                sprintf(string,"this is test String,coming from pid = %d",getpid());
                if(( w = write(s[0] , string , strlen(string) ) ) == -1 ){ 
                        printf("Parent write socket error:%s\n",strerror(errno)); 
                        exit(-1); 
                }
                if((r = read(s[0], buf , BUF_SIZE )) == -1){ 
                    printf("Pid %d read from socket error:%s\n",getpid() , strerror(errno)); 
                }  
        }else if(pid == 0){ 
                printf("Fork child process successed\n"); 
                printf("Child process's pid is :%d\n",getpid());
                //close(s[0]);
                sprintf(string,"this is test String,coming from pid = %d",getpid());
                if(( w = write(s[1] , string , strlen(string) ) ) == -1 ){ 
                        printf("Child write socket error:%s\n",strerror(errno)); 
                        exit(-1); 
                }  
                if((r = read(s[1], buf , BUF_SIZE )) == -1){ 
                    printf("Pid %d read from socket error:%s\n",getpid(), strerror(errno)); 
                }                 
        }else{ 
                printf("Fork failed:%s\n",strerror(errno)); 
                exit(-1); 
        } 
        printf("Pid %d read string in same process : %s.[len=%d]\n",getpid(),buf,r); 
        sleep(300);
        exit(0); 
} 

其逻辑结构如下图: