php多线程下载远程多个文件的例子

<?php
function remote($urls, $name = '', $path = '', $dir = './images/') { 
    if (!is_array($urls) or count($urls) == 0) { 
        return false; 
    } 
    dmkdir($dir); 
    $curl = $text = array(); 
    foreach($urls as $k => $v) { 
        if (!empty($v) && preg_match("~^http~i", $v)) { 
            $nurl[$k] = trim(str_replace(' ', "%20", $v)); 
            $curl[$k] = curl_init($nurl[$k]); 
            curl_setopt($curl[$k], CURLOPT_IPRESOLVE, CURL_IPRESOLVE_V4 ); 
            curl_setopt($curl[$k], CURLOPT_RETURNTRANSFER, 1); 
            curl_setopt($curl[$k], CURLOPT_HEADER, 0); 
            curl_setopt($curl[$k], CURLOPT_CONNECTTIMEOUT, 20); 
            if(!isset($handle)){ 
                $handle = curl_multi_init(); 
            } 
            curl_multi_add_handle($handle, $curl[$k]); 
        } 
        continue ; 
    } 
    $active = null; 
    do{ 
        $mrc = @curl_multi_exec($handle, $active); 
    } while ($mrc == CURLM_CALL_MULTI_PERFORM); 
    while ($active && $mrc == CURLM_OK) { 
        if (curl_multi_select($handle) != -1) { 
            do { 
                $mrc = curl_multi_exec($handle, $active); 
            } while ($mrc == CURLM_CALL_MULTI_PERFORM); 
        } 
    }  //（www.jb200.com 脚本学堂）
    foreach ($curl as $k => $v) { 
            if (curl_error($curl[$k]) == "") { 
                if ($k == 0) { 
                    $fname[$k] = strtolower($name . '.' . pathinfo($urls[$k], PATHINFO_EXTENSION)); 
                } else { 
                    $fname[$k] = strtolower($name . '_' . $k . '.' . pathinfo($urls[$k], PATHINFO_EXTENSION)); 
                } 
                $text[$k] = (string) curl_multi_getcontent($curl[$k]); 
                $filedir[$k] = $dir.'/' . $fname[$k]; 
            if (file_put_contents($filedir[$k], $text[$k])) { 
                $filepath[$k] = $path . $fname[$k]; 
            } 
        } 
        curl_multi_remove_handle($handle, $curl[$k]); 
        curl_close($curl[$k]); 
    } 
    curl_multi_close($handle); 
    return $filepath;