regex - Using preg_replace inside tag -

i change url img src tag value 1 string second this:

   $str1 = "< img src="//d3kq20n0vvk93.cloudfiojiojront.net/cbbcadjiojoijc470efd702jijiojoijiojioc4.jpg" alt="">"; 

to:

  $str2 = "< img src="//d3kq20n0vvk93.cloudfiojiojront.net/cbbcadjiojoijc470efd702jijiojoijiojioc4.jpg?ttl=3600/" alt="">"; 

i tried way doesn't work inside src="" tag:

   print preg_replace('/<img\s.*?\bsrc="(.*?)".*?>/si', "$0?ttl=3600", $str); 

how can resolve it? in advance

it doesn't work because $0 refers whole match (from <img until >) , obtain <img...>?tll=3600.

what need change src content, can:

• use capturing groups:

  echo preg_replace('~(<img\s.*?\bsrc=".*?)(".*?>)~si', '$1?ttl=3600$2', $str);

• use \k (that resets begining of match match result) , lookahead (that performs check , not part of match result)

  echo preg_replace('~<img\s.*?\bsrc=".*?\k(?=".*?>)~si', '?ttl=3600', $str);

however, keep in mind html code can full of traps (attribute between single quotes or no quotes @ all, img tags no src attribute, undefined number of spaces around equal sign, attribute value or text content contains string src="...). reason why, cleanest solution use specific tool deal html.

an example domdocument:

$dom = new domdocument(); @$dom->loadhtml($str); $imgnodes = $dom->getelementsbytagname('img'); foreach($imgnodes $imgnode) {     if ($imgnode->hasattribute('src') && !empty($src = $imgnode->getattribute('src')))         $imgnode->setattribute('src', $src . '?ttl=3600'); } $result = $dom->savehtml(); 

if treat piece of html , not whole document, , if php version greater or equal 5.3.6, can replace last line with:

$result = $dom->savehtml($dom->getelementsbytagname('body')->item(0)); $result = substr($result, 6, -7);