Ruby gsub doesn't escape single-quotes

Question

I don't understand what is going on here. How should I feed gsub to get the string "Yaho\'o"?

>> "Yaho'o".gsub("Y", "\\Y")
=> "\\Yaho'o"
>> "Yaho'o".gsub("'", "\\'")
=> "Yahooo"

This is one of the weirder things I've seen. – Ian Macalinao Oct 19 '15 at 15:42 — Ian Macalinao, Oct 19 '15 at 15:42

score 39 · Accepted Answer · answered Feb 01 '10 at 21:58

39

\' means $' which is everything after the match. Escape the \ again and it works

"Yaho'o".gsub("'", "\\\\'")

answered Feb 01 '10 at 21:58

user163365

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5

ruby 1.9.3 `"Yaho'o".gsub("'", "\\\\'") => "Yaho\\'o"` – Adrien Schuler Feb 19 '13 at 12:55
4

@AdrienSchuler It does work, IRB displays a double backslash so you can see that it's escaped. `"Yaho'o".gsub("'", "\\\\'").length => 7` – Stephen Jennings Nov 25 '14 at 21:26
6

Where is this documented? – Ian Macalinao Oct 19 '15 at 15:46

score 2 · Answer 2 · answered Feb 01 '10 at 21:53

2

"Yaho'o".gsub("'", "\\\\'")

Because you're escaping the escape character as well as escaping the single quote.

answered Feb 01 '10 at 21:53

mopoke

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score 1 · Answer 3 · answered Dec 10 '15 at 20:40

1

This will also do it, and it's a bit more readable:

def escape_single_quotes(str)
  str.gsub(/'/) { |x| "\\#{x}" }
end

If you want to escape both a single-quote and a backslash, so that you can embed that string in a double-quoted ruby string, then the following will do that for you:

def escape_single_quotes_and_backslash(str)
  str.gsub(/\\|'/) { |x| "\\#{x}" }
end

answered Dec 10 '15 at 20:40

jsears

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I used the top one, and it worked perfectly. exactly what I needed. – nfriend21 Sep 22 '16 at 14:44

Ruby gsub doesn't escape single-quotes

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