Download URL links using R

Question

I am new to R and would like to seek some advice.

I am trying to download multiple url links (pdf format, not html) and save it into pdf file format using R.

The links I have are in character (took from the html code of the website).

I tried using download.file() function, but this requires specific url link (Written in R script) and therefore can only download 1 link for 1 file. However I have many url links, and would like to get help in doing this.

Thank you.

Answer 1

I believe what you are trying to do is download a list of URLs, you could try something like this approach:

1. Store all the links in a vector using c(), ej:

urls <- c("http://link1", "http://link2", "http://link3")

2. Iterate through the file and download each file:

for (url in urls) { download.file(url, destfile = basename(url)) }

If you're using Linux/Mac and https you may need to specify method and extra attributes for download.file:

download.file(url, destfile = basename(url), method="curl", extra="-k")

If you want, you can test my proof of concept here: https://gist.github.com/erickthered/7664ec514b0e820a64c8

Hope it helps!

Answer 2

URL

url = c('https://cran.r-project.org/doc/manuals/r-release/R-data.pdf',
        'https://cran.r-project.org/doc/manuals/r-release/R-exts.pdf',
        'http://kenbenoit.net/pdfs/text_analysis_in_R.pdf')

Designated names

names = c('manual1',
          'manual2',
          'manual3')

Iterate through the file and download each file with corresponding name:

for (i in 1:length(url)){
    download.file(url[i], destfile =  names[i], mode = 'wb')
}