1 int main() 2 { 3     char* pipename = "pipe"; 4     mkfifo(pipename,0777); 5     int pid = fork(); 6     if(pid < 0)     7     { 8         printf("Error In Fork\n"); 9         exit(-1);10     }11 12     if(pid == 0)13     {14         printf("In Child Process\n");15         int fd = open(pipename,O_WRONLY|O_NONBLOCK);16         node testnode;17         testnode.a = 10;18         testnode.b = 20;19         20         write(fd,&testnode,sizeof(testnode));21 22         testnode.a = 11;23         testnode.b = 22;24 25         write(fd,&testnode,sizeof(testnode));26 27         close(fd);28         printf("Child Process Is Over \n");29     }30     if(pid > 0)31     {32         33         printf("In Parent Process\n");34         35         int fd = open(pipename,O_RDONLY);36 37         node testnode;38         read(fd,&testnode,sizeof(node));39         printf("Msg From Child node a = %d,b = %ld \n",testnode.a,testnode.b);40 41         read(fd,&testnode,sizeof(node));42         printf("Msg From Child node a = %d,b = %ld \n",testnode.a,testnode.b);43 44         close(fd);45         46         waitpid(pid,NULL,0);47         printf("Praent Process Is Over \n");48     }49 50     51 }

在阻塞情况下，管道会阻塞直到有内容写入

读取时如果管道为空会等待有内容可以读取

在打开管道的时候可以选择非阻塞方式O_NONBLOCK

如果是非阻塞方式则忽略当前管道状态

命名管道不仅可以在有亲缘关系的进程中进行通信，也可以在无亲缘关系的进程中通信。