你怎么看所有输入preceding的CTRL-D顺序？ [英] How do you read all input preceding the CTRL-D sequence?

问题描述

使用系统调用用C阅读

#include <unistd.h>

int main()
{
    char data[128];
    while(read(0, data, 128) == 0){
    read = read(0, data, 128)+ read //counting the amount of chars read in 
 }

    exit(0);
}

我想输入时按CTRL + D终止，这样，用户可以preSS输入，它就会转到新的线路。现在它没有发挥作用的方式。

I would like the input to terminate upon ctrl+d, that way a user can press enter and it will just go to the new line. Right now it is not functioning that way.

读取返回一个整数，表示它读的字节数。我怎么会停止阅读，一旦用户preSS CTRL + D，换句话说，你可以继续阅读，同时pressing进入，但如果按CTRL + D是pssed $ P $，然后回到我多少个字符只读停止。

Read returns a integer indicating the number of bytes it read. How would I stop reading once the user press ctrl + d, in other words you can continue reading while pressing enter but only stop when ctrl+d is pressed and then return how many characters I read.

推荐答案

这听起来像你需要寻找到无缓冲输入。 本网站建议禁止使用termios的功能规范（缓冲）输入。这里的东西我使用示例code它们提供写道。这将允许用户能够输入的文本，直到按下Ctrl-D信号被读取（0X40）在该点它将输出读取的字节数。

It sounds like you need to look into nonbuffered input. This site suggests disabling canonical (buffered) input using termios functions. Here's something I wrote using the sample code they provide. This will allow the user to input text until the Ctrl-D signal is read (0x40) at which point it will output the number of bytes read.

#include <unistd.h>
#include <termios.h>

void print_int(int num);

int main()
{
  struct termios old_tio, new_tio;
  unsigned char c;

  /* get the terminal settings for stdin */
  tcgetattr(STDIN_FILENO, &old_tio);

  /* we want to keep the old setting to restore them a the end */
  new_tio = old_tio;

  /* disable canonical mode (buffered i/o) and local echo */
  new_tio.c_lflag &=(~ICANON & ~ECHOCTL);

  /* set the new settings immediately */
  tcsetattr(STDIN_FILENO, TCSANOW, &new_tio);

  char buf[128] = {0};
  int curr = read(STDIN_FILENO, buf, 128);
  int nbyte = curr;
  while (curr && buf[0] != 0x04) {
    curr = read(STDIN_FILENO, buf, 128);
    nbyte += curr;
  }

  /* restore the former settings */
  tcsetattr(STDIN_FILENO, TCSANOW, &old_tio);

  write(STDOUT_FILENO, "Total bytes: ", 13);
  print_int(nbyte);
  write(STDOUT_FILENO, "\n", 1);

  return 0;
}

void print_int(int num) {
  char temp[16];
  int i = 0, max;
  while (num > 0) {
    temp[i++] = '0'+(num % 10);
    num /= 10;
  }
  max = i;
  for (i=(max-1); i>=0; i--) {
    write(STDOUT_FILENO, &temp[i], 1);
  }
}

请注意，在他们的样本code，它们使用〜ECHO ，但我相信你想看到输入您键入它，所以〜ECHOCTL 将只禁用呼应控制字符（如^ D在输入的结束）。

Note that in their sample code, they use ~ECHO, but I assume you want to see the input as you type it, so ~ECHOCTL will only disable echoing control characters (e.g., the ^D at the end of input).

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