PHP-Curl模拟HTTPS请求

<?php
/**
 * 模拟post进行url请求
 * @param string $url
 * @param array $postData
 */
function request_post($url = '', $postData = []) {
     if (empty($url)) {
         return false;
     }
     if ($postData != []) {
          $vars = http_build_query($postData, '', '&'); 
        curl_setopt($ch, CURLOPT_POSTFIELDS, $vars);
     } 
     $postUrl = $url;
     //初始化curl //转义
     $ch = curl_init();            
     //抓取指定网页 
     curl_setopt($ch, CURLOPT_URL,$postUrl);
     //设置header 
     curl_setopt($ch, CURLOPT_HEADER, 0);
     //要求结果为字符串且输出到屏幕上 
     curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    //规避SSL验证
     curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
    //跳过HOST验证
     curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);
  //header头
    curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-Type: application/json', 'Accept: application/json'));
     //运行curl
     $data = curl_exec($ch); 
     curl_close($ch);
     return $data;
}
/**
 * 测试
 * @param string $url
 */
function testAction() {
     $url = 'https://www.sojson.com/open/api/weather/json.shtml?city=北京';
    $res = request_post($url);
    print_r($res);
}
testAction();