[R] Question about XML package (accurately access one attribute in an multi-attribution node on the web page)

[Humphrey Zhao]

Dear Sir/Madam:

Thank you for your attention to my question. I have downloaded the source code of some web pages by RCurl, and I am trying to extract the URL from them. In these web pages, there are many nodes contains the same URL, such like the followings:

<a href=\"http://cos.name/2015/05/the-data-wisdom-for-data-science/\" rel=\"bookmark\">

<a href=\"http://blog.shakirm.com/2015/03/a-statistical-view-of-deep-learning-ii-auto-encoders-and-free-energy/\" target=\"_blank\">

<a href=\"http://cos.name/2015/05/the-data-wisdom-for-data-science/#more-10947\" class=\"more-link\">

I want to accurately choose the URL I need(the "href" in the first one), and I tried many ways the most accuracy is just like the following:

library(XML)

#links<-getHTMLLinks(base.html, xpQuery = "//a/@href")

links<-getHTMLLinks(base.html, xpQuery = c("//a/href[@rel='bookmark']"))

However, I still believe that there is a correct method to do this very well, but I could not find it. I wonder if you could give me some advice on solving this problem. And I would be most grateful if you could reply at your earliest convenience. Looking forward to hearing from you. Thank you very much.

                                     Sincerely yours 

                                     Humphrey Zhao
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