How do i turn all # tags into a hyperlink?

If this script detects then displays all # tags, how do i change it so it makes t开发者_运维问答hem all a hyper link? Basically putting an <a href="#">infront of it and a </a> behind

$str = <<<STR
this is a string
with a #tag and
another #hello one
STR;

$matches = array();
if (preg_match_all('/#([^\s]+)/', $str, $matches)) {
  var_dump($matches[1]);
}

It sounds like you want to do this:

$str = <<<STR
this is a string
with a #tag and
another #hello one
STR;

$matches = array();
if (preg_match_all('/#([^\s]+)/', $str, $matches)) {
  // Get rid of the full matches
  array_shift($matches);
  // Now get the first array element which are the actual captured matches
  list($matches) = $matches;

  foreach($matches as $match) {
    echo "<a href='#'>{$match}</a>\n";
  }
}

Output:

$ php test.php 
<a href='#'>tag</a>
<a href='#'>hello</a>

You can use back-references, and preg_replace to do this.

echo preg_replace('/#([^\s]+)/', '<a href="#">$1</a>', $str);

Output:

this is a string
with a <a href="#">tag</a> and
another <a href="#">hello</a> one

If you want the # to be part of the link, simply change the regex to /(#[^\s]+)/.

Demo: http://ideone.com/T06HQ

sed 's/#/URL/' myhtmlfile.html

Where URL is the url you want to replace the # with.