r - How to get google search results

Question

I used the following code:

library(XML)
library(RCurl)
getGoogleURL <- function(search.term, domain = '.co.uk', quotes=TRUE) 
    {
    search.term <- gsub(' ', '%20', search.term)
    if(quotes) search.term <- paste('%22', search.term, '%22', sep='') 
        getGoogleURL <- paste('http://www.google', domain, '/search?q=',
        search.term, sep='')
    }

    getGoogleLinks <- function(google.url) 
    {
       doc <- getURL(google.url, httpheader = c("User-Agent" = "R(2.10.0)"))
       html <- htmlTreeParse(doc, useInternalNodes = TRUE, error=function(...){})
       nodes <- getNodeSet(html, "//a[@href][@class='l']")
       return(sapply(nodes, function(x) x <- xmlAttrs(x)[[1]]))
    }

search.term <- "cran"
quotes <- "FALSE"
search.url <- getGoogleURL(search.term=search.term, quotes=quotes)

links <- getGoogleLinks(search.url)

I would like to find all the links that resulted from my search and I get the following result:

> links
list()

How can I get the links? In addition I would like to get the headlines and summary of google results how can I get it? And finally is there a way to get the links that resides in ChillingEffects.org results?

Answer 1

If you look at the htmlvariable, you can see that the search result links all are nested in <h3 class="r"> tags.

Try to change your getGoogleLinks function to:

getGoogleLinks <- function(google.url) {
   doc <- getURL(google.url, httpheader = c("User-Agent" = "R
                                             (2.10.0)"))
   html <- htmlTreeParse(doc, useInternalNodes = TRUE, error=function
                          (...){})
   nodes <- getNodeSet(html, "//h3[@class='r']//a")
   return(sapply(nodes, function(x) x <- xmlAttrs(x)[["href"]]))
}