使用php提取两个字符串之间的数据

Question

I want to extract all the results from top to bottom, i have this script...

function extract_unit($string, $start, $end)
{
$pos = stripos($string, $start);

$str = substr($string, $pos);

$str_two = substr($str, strlen($start));

$second_pos = stripos($str_two, $end);

$str_three = substr($str_two, 0, $second_pos);

$unit = trim($str_three); // remove whitespaces

return $unit;
}

$result = file_get_contents('html.txt');

echo extract_unit($result,'<dd class="m_operation_In">','</dd>');
echo extract_unit($result,'<span class="Unread">','</span>');

This code is working perfect but it is giving me only the first outcome. I want all the outcomes. There are at least 7-8 results that need to be fetched in a single go. I m not sure what to do now. Any kind of help will be appreciated. Thanks

Answer 1

stripos has a third parameter which you can use to fetch later occurrences of your search string. You can loop through all the matches like so:

function extract_unit($string, $start, $end)
{

    $offset = 0;
    $units = array();
    while(($pos = stripos($string, $start) !== false) {
        $str = substr($string, $pos, $offset);
        $str_two = substr($str, strlen($start));
        $second_pos = stripos($str_two, $end);
        $str_three = substr($str_two, 0, $second_pos);

        $units[] = trim($str_three); // remove whitespaces
        $offset = $pos + strlen($start);
    }
    return $units;
}

Note that this approach is extremely brittle - if the html changes even slightly, this code will break; you'd be better off using an html parser to pull out the contents of these divs. The http://www.php.net/manual/en/class.domdocument.php library would be a good place to start.

edit

Using simple_html_dom, you'll just use a css-style selector to get elements you're looking for:

// Create DOM from URL or file
$html = file_get_html('https://www.pourtoi.com.au/link.txt');

// Find all m_operation_In 
foreach($html->find('dd.m_operation_In') as $element) { 
    echo $element->src . '<br>';
}

foreach($html->find('span.Unread') as $span) {
    echo $span->src . '<br/>';
}