解析文件中的数据后使用舍入功能

Question

I have quite a few html files with several links in it. E.g.

<div><a href="/location/?latitude=41.7948205&amp;longitude=-72.12729890000003" >location 1</a></div>
<div><a href="/location/?latitude=41.9020418&amp;longitude=-72.07979440000002" >location 2</a></div>

I want to round the longitude values to 6 decimal places. E.g.

<div><a href="/location/?latitude=41.7948205&amp;longitude=-72.127299" >location 1</a></div>
<div><a href="/location/?latitude=41.9020418&amp;longitude=-72.079794" >location 2</a></div>

I'm a noob when it comes to file parsing and don't know if this is possible. I would appreciate any pointers and guidance.

Answer 1

Here's some PHP code that would do it:

$str = '<div><a href="/location/?latitude=41.7948205&amp;longitude=-72.12729890000003" >location 1</a></div>
<div><a href="/location/?latitude=41.9020418&amp;longitude=-72.07979440000002" >location 2</a></div>
<div><a href="/location/?latitude=41.9020418&amp;longitude=-72.07979440000002" >location 3</a></div>';

$arr = explode("
", $str);

$decimalPlaces = 5;

foreach ($arr as &$line) {
     if (preg_match("/latitude=(.*?)&amp;longitude=(.*?)\"/", $line, $matches)) {
         $latitudeApprox = round($matches[1], $decimalPlaces);
         $longitudeApprox = round($matches[2], $decimalPlaces);
         $line = preg_replace("/latitude=.*?&amp;longitude=.*?\"/", "latitude=$latitudeApprox&amp;longitude=$longitudeApprox\"", $line);
    }
}

$str = implode("
", $arr);
echo $str;

Note that the regex for pulling out the longitude is not very robust. It assumes you never have a case like this, for example:

<a href="/location/?latitude=41.7948205&amp;longitude=-72.12729890000003&amp;SOMETHING+ELSE+HERE" >...</a>