How do I use cookies with RCurl?

In general you don't need to create a cookie file, unless you want to study the cookies.

Given this, in real word, web servers use agent data, redirecting and hidden post data, but this should help:

library(RCurl)#Set your browsing links loginurl = "http://api.my.url/login"dataurl  = "http://api.my.url/data"#Set user account data and agentpars=list(     username="xxx"     password="yyy")agent="Mozilla/5.0" #or whatever #Set RCurl parscurl = getCurlHandle()curlSetOpt(cookiejar="cookies.txt",  useragent = agent, followlocation = TRUE, curl=curl)#Also if you do not need to read the cookies. #curlSetOpt(  cookiejar="", useragent = agent, followlocation = TRUE, curl=curl)#Post login formhtml=postForm(loginurl, .params = pars, curl=curl)#Go wherever you wanthtml=getURL(dataurl, curl=curl)#Start parsing your pagematchref=gregexpr("... my regexp ...", html)#... .... ...#Clean up. This will also print the cookie filerm(curl)gc()

Important

There can often be hidden post data, beyond username and password. To capture it you may want, e.g. in Chrome, to use Developer tools (Ctrl Shift I) -> Network Tab, in order to show the post field names and values.

My bad. Neal Richter pointed out to me http://www.omegahat.org/RCurl/RCurlJSS.pdf - which better explains the difference between cookiefile and cookiejar. The sample script in the question actually does work. But it only writes the file to disk when it is no longer being used.