读取系统调用未检测到文件结尾 [英] Read system call not detecting End of file

问题描述

我已经通过串口将调制解调器连接到我的电脑(linux)，我正在尝试使用写入和读取系统调用从调制解调器写入和读取.在从调制解调器读取所有数据后读取读取系统调用块期间，在我的我已经检查了 eof 的代码，如下所示

I have connected a modem to my pc(linux) through serial port and i am trying to write to and read from modem using write and read system call.During reading read system call blocks after reading all data from modem,in my code i have made check for eof as shown below

  while(1)
  {
      if((rd_cnt =read(fd, &str, 1)) <=0)
    {
            perror("Read to dev failed");
            printf("error no=%d\n",errno);
            break;
    }

        printf("char =%c ->  hex=%x rd_cnt=%d\n",str,str,rd_cnt);
        sleep(3);
        str=0;
 }      

 if(rd_cnt==0)
    printf("EOF met\n");

但我从来没有收到过 eof，我想读取从调制解调器发送的所有数据，直到遇到文件结尾.请指导我.

but i have never got eof,i wanted to read all the data send from modem till i meet end of file. Please guide me.

推荐答案

像这样改变你的代码

if((rd_cnt =read(fd, &str, sizeof(str))) <=0)
    {
            perror("Read to dev failed");
            printf("error no=%d\n",errno);
            break;
    }

检查EOF条件即可.

无需再次编写此代码，因为您已经在检查它.

No need to write this code again as you are already checking this.

//if(rd_cnt==0)
    //printf("EOF met\n");

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