php 判断页面或图片是否经过gzip压缩的方法

<?phpob_start('ob_gzhandler'); // 开启gzip，屏蔽则关闭$data = array( array('name'=>'one','value'=>1), array('name'=>'two','value'=>2), array('name'=>'three','value'=>3));header('content-type:application/json');echo json_encode($data);?>

<?php$url = 'http://www.example.com/';var_dump(check_gzip($url));/** * 判断url是否经过gzip压缩 * @param String $url 来源 * @param Boolean */function check_gzip($url){ $header = get_headers($url, 1); if(isset($header['Vary']) && $header['Vary']=='Accept-Encoding'){  return true; } return false;}?>

<?phpheader('content-type:image/jpeg');ob_start('ob_gzhandler'); // 开启gzip，屏蔽则关闭echo file_get_contents('test.jpg');?>

<?php$url = 'http://www.example.com/';var_dump(check_gzip($url));/** * 判断url是否经过gzip压缩 * @param String $url 来源 * @param Boolean */function check_gzip($url){ $ch = curl_init(); curl_setopt($ch, CURLOPT_URL, $url); curl_setopt($ch, CURLOPT_HEADER, 1);   // 输出header信息 curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1); // 返回的信息不直接输出 curl_setopt($ch, CURLOPT_ENCODING, '');  // 不限制编码类型 $response = curl_exec($ch); if(!curl_errno($ch)){  $info = curl_getinfo($ch);  // 获取header  $header_size = $info['header_size'];  $header_str = substr($response, 0, $header_size);  $filter = array("/r/n", "/r");  $header_str = str_replace($filter, PHP_EOL, $header_str);  // 检查content-encoding  preg_match('/Content-Encoding: (.*)/s/i', $header_str, $matches);  if(isset($matches[1]) && $matches[1]=='gzip'){   return true;  } } return false;}?>