Convert string to HEX in R

user_9108085 0
Viewed 1018

I search everywhere for an answer but could not find the right one. I need to convert a string to a specific encoding in R, but was not able to do so:

string <- "überhaupt"

What I need: "&#xfc;berhaupt"

to following functions I have used so far:

textutils::HTMLencode(string) gives:  "&uuml;berhaupt"
utf8::utf8_print(string, utf8 = F) gives:  "\u00fcberhaupt"
iconv(string, from = "windows-1252", "utf-8") gives: "überhaupt"

It seems that I need the hex Numeric character reference https://en.wikipedia.org/wiki/%C3%9C but I don't know how to convert.

Thanks for your help

utf-8 r
2 Answers

So it looks like you want the "numeric character reference" encoding from that page. I'm not sure if there is a built in function for that, but this is one attempt at writing such a function

char_ref_encode <- function(x) {
  cp <- charToRaw(x)
  parts <- rle(cp>127)
  with(parts, {
    starts <- head(cumsum(c(0, lengths)), -1) + 1
    ends <- cumsum(lengths)
    paste0(mapply(function(v, start, end) {
      if (v) {
        paste(sprintf("&#x%02x;", as.numeric(cp[start:end])), collapse="")
      } else {
        intToUtf8(cp[start:end])
      }
    }, values, starts, ends), collapse="")
  })
}

char_ref_encode("überhaupt")
# [1] "&#xfc;berhaupt"

The basic idea is to look for all the non-ascii characters and then encoding them with their hex values.

user_23720640

I have now found the perfect answer. So it should work on all systems:

function(x){
x%>%
str_extract_all(., "[:print:]")%>%
map(.x = ., ~stringi::stri_escape_unicode(.x))%>%
map(.x = ., ~str_replace_all(.x, "\\\\u0*", "&#x" ))%>%
map(.x = ., ~case_when(
str_detect(.x, "&#x") ~ str_c(.x, ";"),
T ~.x))%>%
map(.x =., ~str_c(.x, collapse = ""))%>%
unlist()
}

Thanks @MrFlick for your help!

user_91080850
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