php解析字符串里所有URL地址的方法

<?php // $html = the html on the page // $current_url = the full url that the html came from //(only needed for $repath) // $repath = converts ../ and / and // urls to full valid urls function pageLinks($html, $current_url = "", $repath = false){ preg_match_all("/\<a.+?href=(\"|')(?!javascript:|#)(.+?)(\"|')/i", $html, $matches); $links = array(); if(isset($matches[2])){ $links = $matches[2]; } if($repath && count($links) > 0 && strlen($current_url) > 0){ $pathi = pathinfo($current_url); $dir = $pathi["dirname"]; $base = parse_url($current_url); $split_path = explode("https://www.jb51.net/", $dir); $url = ""; foreach($links as $k => $link){ if(preg_match("/^\.\./", $link)){ $total = substr_count($link, "../"); for($i = 0; $i < $total; $i++){ array_pop($split_path); } $url = implode("https://www.jb51.net/", $split_path) . "https://www.jb51.net/" . str_replace("../", "", $link); }elseif(preg_match("/^\/\//", $link)){ $url = $base["scheme"] . ":" . $link; }elseif(preg_match("/^\/|^.\//", $link)){ $url = $base["scheme"] . "://" . $base["host"] . $link; }elseif(preg_match("/^[a-zA-Z0-9]/", $link)){ if(preg_match("/^http/", $link)){ $url = $link; }else{ $url = $dir . "https://www.jb51.net/" . $link; } } $links[$k] = $url; } } return $links; } header("content-type: text/plain"); $url = "https://www.jb51.net"; $html = file_get_contents($url); // Gets links from the page: print_r(pageLinks($html)); // Gets links from the page and formats them to a full valid url: print_r(pageLinks($html, $url, true));