对于以4个空格开头的每一行，添加text-indent标记

I've got text where some lines are indented with 4 spaces. I've been trying to write a regex which would find every line beginning with 4 spaces and put a <span class="indented"> at the beginning and a </span> at the end. I'm no good at regex yet, though, so it came to nothing. Is there a way to do it?

我有一些文本，其中一些行缩进4个空格。我一直在尝试编写一个正则表达式，它会找到以4个空格开头的每一行，并在开头放一个，在结尾放一个。不过，我对正则表达式并不擅长，所以它一无所获。有办法吗？

(I'm working in PHP, in case there's an option easier than regex).

（我正在使用PHP，以防有一个比正则表达式更容易的选项）。

Example:

例：

Text text text
    Indented text text text
More text text text
A bit more text text.

to:

至：

Text text text
<span class="indented">Indented text text text</span>
More text text text
A bit more text text.

3 个解决方案

#1

The following will match lines starting with at least 4 spaces or a tab character:

以下将匹配以至少4个空格或制表符开头的行：

$str = preg_replace("/^(?: {4,}|\t *)(.*)$/m", "<span class=\"indented\">$1</span>", $str);

#2

I had to do something similar, and one thing I might suggest is changing the goal formatting to be

我必须做类似的事情，我可能建议的一件事就是改变目标格式

<span class="tab"></span>Indented text text text

You can then set your css something like .tab {width:4em;} and instead of using preg_replace and regexes, you can do

然后你可以设置你的CSS像.tab {width：4em;}而不是使用preg_replace和regexes，你可以做

str_replace($str, "    ", "<span class='tab'></span>");

This has the benefit of allowing for 8 spaces to turn into a double width tab easily.

这有利于允许8个空间容易地变成双宽度标签。

#3

I think this should work:

我认为这应该有效：

//get each line as an item in an array
$array_of_lines = explode("\n", $your_string_of_lines);

foreach($array_of_lines as $line) {
    // First four characters
    $first_four = substr($line, 0, 4);
    if($first_four == '    ') {
        $line = trim($line);
        $line = '<span class="indented">'.$line.'</span>'; 
    }

    $output[] = $line;
}

echo implode("\n",$output);

#1