Question

我有function，只接受有效输入。在这种情况下，有效输入将是integer值更大零和小UCHAR_MAX。如果输入无效，则应抛出[ERR] -message 在一个新的行。问题在于，虽然ist工作应该按字符的方式，它不应该按照它应该的方式工作当值超出定义范围(0 < input < UCHAR_MAX)时。这意味着当输入类似于-42或1337时，它就会产生 [ERR] - 消息等待另一行“输入”。

为什么它会创建一个额外的新行，等待另一个“输入”，而它是按字符工作的，我该如何克服这个问题呢？

int get_int(void)
{
  char lsc;   // least significant char - stores the last char at scanf()
  char correct_input = 'f'; // boolean value to exit the while-loop
  int input = 0;            // stores the users input
  int return_value = 0;     // stores the return value of scanf();

  while (correct_input == 'f') {
    printf("Please enter an unsigend integer value greater zero: ");
    return_value = scanf("%d%c", &input, &lsc);

    if (return_value == 2 && lsc == '\n' && UCHAR_MAX > input && input > 0)
    {
      printf("[OK]  Valid input.\n");
      correct_input = 't';
    }
    else if (return_value == EOF) {
      exit(0);
    }
    else
    {
      printf("[ERR] Invalid input!\n");
      while(getchar() != '\n');    // flushes the scanf()-buffer
    }
  }
  return input;
}

产生的结果：

Please enter a unsigend integer value greater zero: foo
[ERR] Invalid input!
Please enter a unsigend integer value greater zero: 1337
[ERR] Invalid input!

Please enter a unsigend integer value greater zero: -42
[ERR] Invalid input!

Please enter a unsigend integer value greater zero: 5
[OK]  Valid input.

如上所示，当值超出范围时，会产生额外的新行。

我很感激任何帮助，链接，参考和提示！

Answer 1

那么为什么当值超出范围时会产生新的线？

它不再产生一条新线;由于while(getchar() != '\n')，它等待你输入一个。

我怎样才能克服这个问题？

while(getchar() != '\n')如果scanf()已读取换行符，则跳过if (return_value < 2 || lsc != '\n') // do only if \n not already read while(getchar() != '\n'); // flushes the scanf()-buffer。

function my_clickable_links( $text ) {
    $patt = array(
        '%\b(?<!href=[\'"])(?>https?://|www\.)([\p{L}\p{N}]+[\p{L}\p{N}\-]*\.(?:[\p{L}\p{N}\-]+\.)*[\p{L}\p{N}]{2,})(?::\d+)?(?:(?:(?:/[\p{L}\p{N}$_\.\+!\*\'\(\),\%;:@&=-]+)+|/)(?:\?[\p{L}\p{N}$_\.\+!\*\'\(\),\%;:@&=-]+)?(?:#[^\s\<\>]+)?)?(?![^<]*+</a>)%u',
        '%\b(?<!http://)(?<!https://)([\p{L}\p{N}]+[\p{L}\p{N}\-]*\.(?:[\p{L}\p{N}\-]+\.)*(?:ru|com|net))(?::\d+)?(?:(?:(?:/[\p{L}\p{N}$_\.\+!\*\'\(\),\%;:@&=-]+)+|/)(?:\?[\p{L}\p{N}$_\.\+!\*\'\(\),\%;:@&=-]+)?(?:#[^\s\<\>]+)?|\b)(?![^<]*+</a>)%u'
    );
    $repl = array(
        '<a href="$0">$1</a>',
        '<a href="http://$0">$1</a>'
    );
    $text = preg_replace($patt, $repl, $text);
    echo $text;
}
add_filter( 'the_content', 'my_clickable_links', 12 );

Answer 2

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为什么我的功能会产生额外的新线？

2 个答案: