有时候为了测试网络情况，需要返回每个阶段的耗时时间，比如DNS解析耗时，建立连接所消耗的时间，从建立连接到准备传输所使用的时间，从建立连接到传输开始所使用的时间，整个过程耗时，下载的数据量，下载速度，上传数据量，上传速度等等。下面的脚本获取以上信息：

CURL的资料参见： http://curl.haxx.se/libcurl/c/curl_easy_getinfo.html

复制代码 代码如下:
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### author: plete upload. Bytes per second.)

content_type 就是content-Type，不用多说了，这是一个访问我博客首页返回的结果示例(text/html; charset=UTF-8)；(The Content-Type of the requested document, if there was any.)

num_connects Number of new connects made in the recent transfer. (Added in 7.12.3)

num_redirects Number of redirects that were followed in the request. (Added in 7.12.3)

redirect_url When a HTTP request was made without -L to follow redirects, this variable will show the actual URL a redirect would take you to. (Added in 7.18.2)

ftp_entry_path The initial path libcurl ended up in when logging on to the remote FTP server. (Added in 7.15.4)

ssl_verify_result ssl认证结果，返回0表示认证成功。( The result of the SSL peer certificate verification that was requested. 0 means the verification was successful. (Added in 7.19.0))

若多次使用-w参数，按最后一个的格式输出。If this option is used several times, the last one will be used.