我在Linux的C语言中使用管道时遇到问题。我的工作如下:

用c编写一个程序,它将创建一个孩子。子进程将使用管道与父进程进行通信。父亲进程将给出一个0 = y之间的随机数,然后父亲会向用户询问他的名字,然后他会像这样发布它(George-> egroeG)。

我的代码如下:

   #include <stdio.h>
   #include <stdlib.h>
   #include <string.h>
   #include <signal.h>
   #include <unistd.h>
   #include <fcntl.h>

void myalarm(int sig) {
 printf("\nTime is out. Exiting...\n");
 exit(0);
}
int main(int argc, char **argv){

   int x, x1, n, m, pid, fd1[2];
   int y = rand() % 100 + 2;
   int i=0;
   char *name, *arxi;

 if (pipe(fd1) == -1) {
  perror("ERROR: Creating Pipe\n");
  exit(1);
 }
  pid = fork();
   switch(pid) {
    case -1:
     perror("ERROR: Creating Child Proccess\n");
     exit(99);
    case 0:
     close(fd1[0]);   /*Writer*/
     printf("\nGive a number between 1 & 100:\n");
     scanf("%d", &x);

     n = write(fd1[1], x, 1);
/*dup2(fd1[0],0);*/
      while (x < 0 || x > 100) {
       printf("ERROR:You gave a wrong number...");
       printf("\nGive a number between 1 & 100:\n");
       scanf("%d", &x);
      }
     close(fd1[1]);
     break;
    default:
     close(fd1[1]);   /*Reader*/
     printf("I Am The Father Process...\n");
     printf("y = %d\n", y);

     m = read(fd1[0], x1, 0);
/*dup2(fd1[1],1);*/   close(fd1[0]);

      if (x1 < y) {
       kill(pid, SIGTERM); //termination of the child process

      }
      else {
       signal(SIGALRM, myalarm);
       printf("Please, type in your name:\n");
       fflush(stdout);
       alarm(10);   //Start a 10 seconds alarm
       scanf("%s", name);
       arxi = name;
       alarm(0);
        while(*name != '\0') {
         name++;
        }
        name--;
        while(name >= arxi) {
         putchar(*name);
         name--;
        }
       printf("%s\n", name);
      }
     wait(&pid);
     break;
   }
return 0;
}

最佳答案

可能还有其他问题,但这些问题跳错了:

n = write(fd1[1], x, 1);


这将从地址x写入1个字节,这可能会崩溃。你要:

n = write(fd1[1], &x, sizeof(x));


同样,这将向地址x1读取0字节,这将不执行任何操作:

m = read(fd1[0], x1, 0);


你要:

m = read(fd1[0], &x1, sizeof(x1));

10-08 05:12