Question

i) 有一些法典可重复使用:

printf("do you want to continue? Y/N: ");
keepplaying = getchar();

in the next my code is running it doesnt wait for input. i found out that getchar in the seconed time use as the charcter. im gussing this is due to some buffer the sdio has, so it save the last input which was "Y " or "N ".

我的问道是,如何在使用沙子之前绕过缓冲? 这将使我等待回答吗?

Answer 1

挥发投入导致行为不明确。

in(FILE *ostream);

ostream points to an output stream or an update stream in which the most recent operation was not input, the fflush function causes any unwritten data for that stream to be delivered to the host environment to be written to the file; otherwise, the behavior is undefined.

适当吸收投入,如:

int main(void)
{
  int   ch;
  char  buf[BUFSIZ];

  puts("Flushing input");

  while ((ch = getchar()) !=  
  && ch != EOF);

  printf ("Enter some text: ");

  if (fgets(buf, sizeof(buf), stdin))
  {
    printf ("You entered: %s", buf);
  }

  return 0;
}

见。为什么fflush(stdin)是错的和。

Answer 2

在打印前使用fflush()和氟()

Answer 3

如我所知,<代码>flushall不是 POSIX。为了以标准方式变换独ole的缓冲,你可以简单地利用指挥:

fflush(NULL);

This topic seems to be a bit old but I hope this can still help the others.

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