urlExists <- function(address) {
tryCatch {
con <- url(address)
a <- capture.output(suppressWarnings(readLines(con)))
close(con)
TRUE;
},
error = function(err) {
occur <- grep("cannot open the connection", capture.output(err));
if(length(occur) > 0) FALSE;
}
)
}
Thursday, 22 March 2012
Check URL existance with R
RCurl package provides utilities for HTTP and FTP connection. One particular functionality is checking if a given URL is accessible, implying existence, using url.exists. However some unfortunate Windows users may have difficulty to get its latest build from CRAN. Here is a simple function to check existence of URL by only using R base functionality;