r - 获取响应头

Question

我想从 GET 或 POST 获取响应 header 。

我的例子是:

    library(httr)
    library(RCurl)
    url<-'http://www.omegahat.org/RCurl/philosophy.html'
    doc<-GET(url)
    names(doc)

[1] "url"         "handle"      "status_code" "headers"     "cookies"     "content"     "times"       "config"  

但是没有响应头，只有请求头。

结果应该是这样的:

Connection:Keep-Alive
Date:Mon, 11 Feb 2013 20:21:56 GMT
ETag:"126a001-e33d-4c12cf2702440"
Keep-Alive:timeout=15, max=100
Server:Apache/2.2.14 (Ubuntu)
Vary:Accept-Encoding

我可以使用 R 和 httr/RCurl 包来做到这一点，还是 R 不足以解决此类问题？

编辑 : 我想得到所有的响应头。我主要对 感兴趣地点 不在此示例中的响应。

编辑 2 : 我忘了告诉我工作的系统 - 它是 Windows 7

我的 session.info

> sessionInfo()
R version 2.15.2 (2012-10-26)
Platform: x86_64-w64-mingw32/x64 (64-bit)

locale:
[1] LC_COLLATE=Polish_Poland.1250  LC_CTYPE=Polish_Poland.1250    LC_MONETARY=Polish_Poland.1250
[4] LC_NUMERIC=C                   LC_TIME=Polish_Poland.1250    

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] rjson_0.2.12 RCurl_1.95-3 bitops_1.0-5 httr_0.2     XML_3.95-0.1

loaded via a namespace (and not attached):
[1] digest_0.6.2  stringr_0.6.2 tools_2.15.2 

Answer 1

你可以这样做:

h <- basicHeaderGatherer()
doc <- getURI("http://www.omegahat.org/RCurl/index.html", headerfunction = h$update)
h$value()

这会给你一个命名向量:

                            Date                           Server 
 "Mon, 11 Feb 2013 20:41:58 GMT"         "Apache/2.2.14 (Ubuntu)" 
                   Last-Modified                             ETag 
 "Wed, 24 Oct 2012 15:49:35 GMT" "\"3262089-10bf-4ccd0088461c0\"" 
                   Accept-Ranges                   Content-Length 
                         "bytes"                           "4287" 
                            Vary                     Content-Type 
               "Accept-Encoding"                      "text/html" 
                          status                    statusMessage 
                           "200"                             "OK"