How to read quoted text containing escaped quotes

Question

Consider the following comma separated file. For simplicity let it contain one line:

---

\'I am quoted\',\'so, can use comma inside - it is not separator h         


        

Answer 1

read_delim from package readr can handle escaped quotes, using the arguments escape_double and escape_backslash.

read_delim(file, delim=',', escape_double=FALSE, escape_backslash=TRUE, quote="'")

(Note older versions of readr do not support quoted newlines in CSV headers correctly: https://github.com/tidyverse/readr/issues/784)

Answer 2

One possibility is to use readLines() to get everything read in as is, and then proceed by replacing the quote character by something else, eg :

tt <- readLines("F:/temp/test.txt")
tt <- gsub("([^\\]|^)'","\\1\"",tt) # replace ' by "
tt <- gsub("\\\\","\\",tt) # get rid of the double escape due to readLines

This allows you to read the vector tt in using a textConnection

zz <- textConnection(tt)
read.csv(zz,header=F,quote="\"") # give text input
close(zz)

Not the most beautiful solution, but it works (provided you don't have a " character somewhere in the file off course...)