無名管道系統調用

#include #include #include #include #include #include #define MAX 256 #define DELAY 1 int main() { pid_t pid; int pipe_fd[2]; //定義兩個文件描述符 char buf[MAX]; //定義緩衝區大小 const char data[] = "Pipe Test Program"; //定義數據 int real_read,real_write; memset((void*)buf,0,sizeof(buf)); //清空內存區 if(pipe(pipe_fd) < 0) //創建管道 { printf("pipe create error/n"); exit(1); } if((pid = fork()) == 0) //創建一子進程 {//子進程關閉寫描述符，並通過子進程暫停1s等待父進程已關閉相應的讀描述符 close(pipe_fd[1]); sleep(DELAY * 3); if((real_read = read(pipe_fd[0],buf,MAX)) > 0) //子進程讀取管道內容 { printf("%d bytes read from the pipe is '%s'/n",real_read,buf); } close(pipe_fd[0]); //關閉子進程讀描述符 exit(0); } else if(pid > 0) {//父進程關閉讀描述符，並通過使使父進程暫停1s等待子進程已關閉相應的寫描述符 close(pipe_fd[0]); sleep(DELAY); if((real_write = write(pipe_fd[1],data,strlen(data))) != -1) //父進程寫入管道內容 { printf("Parent wrote %d bytes:'%s'/n",real_write,data); } close(pipe_fd[1]); //關閉父進程寫描述符 waitpid(pid,NULL,0); //收集子進程退出信息 exit(0); } }