I am trying to clean a list of pdfs of links. I want to include this in my cleaning function and therefore use regexes. And yes, I spend more time than I like to admit googling and browsing though questions here. My pdfs are split into lines, so it is not one consecutive string. I have a piece of code that gives me only one link as result (even though there should be many). All other options I tried included a lot of text I want to keep in my dataset.
I have tried multiple options outside my function but they will not run on texts, only on examples.
I want to catch everything from the www to the first white space after all the things that come after the .org or .html or whatever (e.g. /questions/ask/somethingelse
I tried simulating some things
w <- "www.smthing.org/knowledge/school/principal.\r"
z <- "www.oecd.de\r"
x <- "www.bla.pdfwerr\r .irgendwas" # should not catch that, too many characters after the .
m <- " www.cognitioninstitute.org/index.php/Publications/
bla test smth
.gtw, www.stmthing-else.html.\r"
n <- "decoy"
l <- list(w,z,x,m,n)
regmatches(l, regexpr("w{3}\\.[a-z]*\\.[a-z]{2,4}.*?[[:space:]]", l))
My current working state also only catches the first occurence in that particular line, instead stopping at the space (line m in my example) and then including the next link as well.
You may use
regmatches(l, gregexpr("w{3}\\.\\S*\\b", l))
The gregexpr function will let you extract all occurrences of the pattern.
Note that most users prefer spelling out www instead of using w{3}.
Pattern details
w{3} - three w chars\\. - a dot\\S* - zero or more non-whitespace chars\\b - word boundary.