Question

我正在输入一个脏字符串（标点符号前面有很多空格，换行符和额外的虚假空格。

我想要的输出在下面的代码中解释。

似乎我可以在标点字符之前删除多余的空格+以删除空格。 但我的输出仍有不必要的多余换行符。

当我将用户输入从MySQL db打印到屏幕时，我使用下面的函数。

echo "\t\t".'<p>'.nl2br(convert_str(htmlspecialchars($comment))).'</p>'."\r\n";

我的自定义功能代码如下：

function convert_str ($str)
{
    // remove excess whitespace
    // looks for a one or more spaces and replaces them all with a single space.
    $str = preg_replace('/ +/', ' ', $str);
    // check for instances of more than two line breaks in a row
    // and then change them to a total of two line breaks
    //did not worked for me --> preg_replace('/(?:(?:\r\n|\r|\n)\s*){2}/s', "\n\n", $str);
    $str = preg_replace('/[ \t]+/', ' ', preg_replace('/\s*$^\s*/m', "\n", $str));
    // if exists; remove 1 space character just before punctuations below:
    // $punc = array('.',',',';',':','...','?','!','-','—','/','\\','“','”','‘','’','"','\'','(',')','[',']','’','{','}','*','&','#','^','<','>','|');
    $punc = array(' .',' ,',' ;',' :',' ...',' ?',' !',' -',' —',' /',' \\',' “',' ”',' ‘',' ’',' "',' \'',' (',' )',' [',' ]',' ’',' {',' }',' *',' &',' #',' ^',' <',' >',' |');
    $replace = array('.',',',';',':','...','?','!','-','—','/','\\','“','”','‘','’','"','\'','(',')','[',']','’','{','}','*','&','#','^','<','>','|');
    $str = str_replace($punc,$replace,$str);
    return $str;
}

你能纠正我吗？

更新：我使用预准备语句将用户输入输入到MySQL数据库表中，并且在进入数据库时我不会操纵用户数据。

Answer 1

我发现了一个简单但耗时5小时的原因：只使用\n代替\r\n。

所以满足我要求的代码是：

function convert_str ($str)
{
    // remove excess whitespace
    // looks for a one or more spaces and replaces them all with a single space.
    $str = preg_replace('/ +/', ' ', $str);
    // check for instances of more than two line breaks in a row
    // and then change them to a total of two line breaks
    $str = preg_replace('/(?:(?:\r\n|\r|\n)\s*){2}/s', "\r\n\r\n", $str);
    // if exists; remove 1 space character just before punctuations below:
    // $punc = array('.',',',';',':','...','?','!','-','—','/','\\','“','”','‘','’','"','\'','(',')','[',']','’','{','}','*','&','#','^','<','>','|');
    $punc = array(' .',' ,',' ;',' :',' ...',' ?',' !',' -',' —',' /',' \\',' “',' ”',' ‘',' ’',' "',' \'',' (',' )',' [',' ]',' ’',' {',' }',' *',' &',' #',' ^',' <',' >',' |');
    $replace = array('.',',',';',':','...','?','!','-','—','/','\\','“','”','‘','’','"','\'','(',')','[',']','’','{','}','*','&','#','^','<','>','|');
    $str = str_replace($punc,$replace,$str);
    return $str;
}

PHP REGEX - 删除多余的换行符 - String Manipulation Issue

1 个答案: