I am trying to get a list of URLs from a parent database that are constructed of two different keys:

1. The relevant key to the sub folder
2. The pertinent key to the specific file

The sub folder key is held in a CSV file and so the concatenation is relatively simple:

csv <- read.csv("raw.csv")
vec <- csv$col1

URLs <- paste0("https://www.abc-corp.com/data/", vec, "/gotit/")

This returns a list of partial URLs but then it gets tricky.

The next section is a block of digits with 5 irrelevant ones, the year anotated in shorthand, then three more, e.g https://www.abc-corp.com/data/1234/gotit/1234522123"

I've tried:

URLs <- paste0("https://www.abc-corp.com/data/", vec, "/gotit/", "\d\d\d\d\d", "22", "\d\d\d")

and been told:

Error: '\d' is an unrecognized escape in character string starting ""\d\d"

It seems to be putting in an extra speech mark as well as not recognising the regex.

CodePudding user response：

You will need to add 2 backslashes for each individual slash. Additionally you may want to use quantifiers instead of repeating \d.

URLs <- paste0("https://www.abc-corp.com/data/", vec, "/gotit/", "\\d{5}", "22", "\\d{3}")