# Gsub!("\\n","\\n") **URL:** \ **Category:** Ruby\ **Created:** [January 20, 2009, 1:20am UTC](https://www.ruby-forum.com/t/gsub-n-n/158169 "2009-01-20T01:20:31Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![simon1tan](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/9e8a1a/32.png) [@simon1tan](https://www.ruby-forum.com/u/simon1tan)\ **Post date:** [January 20, 2009, 1:20am UTC](https://www.ruby-forum.com/t/gsub-n-n/158169/1 "2009-01-20T01:20:31Z")
Hi all, I’m not sure why but I assumed gsub! would allow me to replace \n with line feeds or \r for carriage returns. How do I gsub! and replace everything with a nonvisible character like newline? I was using this results.gsub!("\n","\n") but obviously that does not work ☹ also tried results.gsub!("\n",10.chr). No go. Kinda of frustrating for something so simple. I guess I could always do some recursion. Thanks. ---
**Author:** ![simon1tan](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/9e8a1a/32.png) [@simon1tan](https://www.ruby-forum.com/u/simon1tan)\ **Post date:** [January 20, 2009, 1:53am UTC](https://www.ruby-forum.com/t/gsub-n-n/158169/2 "2009-01-20T01:53:22Z")
On Jan 19, 2009, at 7:19 PM, Simon T. wrote: > – > Are you trying to turn this: Hello, World Into something like: Hello,\nWorld If so, you need to change “\n” (1 character string) into “\\n” (3 character string, two escaped backslashs and the letter ‘n’). The replacement string will undergo two different interpretations: as a string literal “\\n” becomes \n which when interpreted as a replacement for a regexp undergoes another round (so that things like \1 and \2 can reference groups in the regexp) and becomes \n Yes, this is tricky, but it’s because there are two levels of escaping going on and both use the backslash. -Rob Rob B. [http://agileconsultingllc.com](http://agileconsultingllc.com) removed\_email\_address@domain.invalid ---
**Author:** ![simon1tan](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/9e8a1a/32.png) [@simon1tan](https://www.ruby-forum.com/u/simon1tan)\ **Post date:** [January 20, 2009, 2:18am UTC](https://www.ruby-forum.com/t/gsub-n-n/158169/3 "2009-01-20T02:18:09Z")
haha actually, the other way around 🙂 I have a string(I believe…I’m using Hpricot to retreive web pages and it likes to add slashes to everything). For example, I want to change “Hello, \nWorld” by changing \n into a newline. So the output should be like: Hello World I did try your suggestion, but I get “Hello\nWorld”. Will keep playing with the slashes. Rob B. wrote: > On Jan 19, 2009, at 7:19 PM, Simon T. wrote: > > > – > > Are you trying to turn this: > > Hello, > World > > Into something like: > > Hello,\nWorld > > If so, you need to change “\n” (1 character string) into “\\n” (3 > character string, two escaped backslashs and the letter ‘n’). The > replacement string will undergo two different interpretations: as a > string literal “\\n” becomes \n which when interpreted as a > replacement for a regexp undergoes another round (so that things like > \1 and \2 can reference groups in the regexp) and becomes \n > > Yes, this is tricky, but it’s because there are two levels of escaping > going on and both use the backslash. > > -Rob > > Rob B. [http://agileconsultingllc.com](http://agileconsultingllc.com) > removed\_email\_address@domain.invalid ---
**Author:** ![simon1tan](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/9e8a1a/32.png) [@simon1tan](https://www.ruby-forum.com/u/simon1tan)\ **Post date:** [January 20, 2009, 2:46am UTC](https://www.ruby-forum.com/t/gsub-n-n/158169/4 "2009-01-20T02:46:35Z")
Are you seeing something like: irb\> look = ‘here is a " and I'll put a ' here, too’ =\> “here is a " and I’ll put a ’ here, too” irb\> puts look here is a " and I’ll put a ’ here, too =\> nil The rules for what needs to be escaped depend on the kind of quotes used. Are you seeing output that is shown in double quotes to indicate that it is a string? -Rob On Jan 19, 2009, at 8:16 PM, Simon T. wrote: > I did try your suggestion, but I get “Hello\nWorld”. Will keep > > > World > > \1 and \2 can reference groups in the regexp) and becomes \n > > – > > Posted via [http://www.ruby-forum.com/](http://www.ruby-forum.com/). Rob B. [http://agileconsultingllc.com](http://agileconsultingllc.com) removed\_email\_address@domain.invalid +1 513-295-4739 Skype: rob.biedenharn ---
**Author:** ![simon1tan](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/9e8a1a/32.png) [@simon1tan](https://www.ruby-forum.com/u/simon1tan)\ **Post date:** [January 20, 2009, 8:50am UTC](https://www.ruby-forum.com/t/gsub-n-n/158169/5 "2009-01-20T08:50:29Z")
Simon T. wrote: If you want to substitute Hello\nWorld by Hello World you should try to work with single quotes: a = ‘Hello\nWorld’ Simon T. wrote: =\> “Hello\nWorld” irb(main):002:0\> puts a Hello\nWorld =\> nil irb(main):003:0\> a.gsub!(’\n’,"\n") =\> “Hello\nWorld” irb(main):004:0\> puts a Hello World ---
**Author:** ![simon1tan](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/9e8a1a/32.png) [@simon1tan](https://www.ruby-forum.com/u/simon1tan)\ **Post date:** [January 20, 2009, 5:08am UTC](https://www.ruby-forum.com/t/gsub-n-n/158169/6 "2009-01-20T05:08:08Z")
Hi, Am Dienstag, 20. Jan 2009, 09:19:02 +0900 schrieb Simon T.: > Hi all, I’m not sure why but I assumed gsub! would allow me to replace > \n with line feeds or \r for carriage returns. str.gsub! “\n”, “\n” str.gsub! “\r”, “\r” This is a security risk: eval %Q("#{str}") Maybe this does: str = “hello\nbye” str.gsub! /\(\w)/ do |m| eval ‘"\’ + $1 + ‘"’ end Okay, \ escaping is a weird matter. You know that gsub! returns nil in case nothing was changed? Bertram ---
**Author:** ![simon1tan](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/9e8a1a/32.png) [@simon1tan](https://www.ruby-forum.com/u/simon1tan)\ **Post date:** [January 20, 2009, 10:50pm UTC](https://www.ruby-forum.com/t/gsub-n-n/158169/7 "2009-01-20T22:50:26Z")
Simon T. wrote: > I have a string(I believe…I’m > using Hpricot to retreive web pages and it likes to add slashes to > everything). For example, I want to change “Hello, \nWorld” by changing > \n into a newline. Perhaps there’s a misunderstanding here. I doubt Hpricot adds anything. If you see this “Hello, \nWorld” in ‘irb’ then that’s because ‘irb’ shows you the string in the way you’d write it in your source-code. The two characters “\n” are actually a newline. ---
**Author:** ![simon1tan](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/9e8a1a/32.png) [@simon1tan](https://www.ruby-forum.com/u/simon1tan)\ **Post date:** [January 25, 2009, 1:27am UTC](https://www.ruby-forum.com/t/gsub-n-n/158169/8 "2009-01-25T01:27:05Z")
Ok, I just realized I’ve been using p to print everything out! “Puts” works a whole lot better. Doh! Thanks for all the help. Sorry for phrasing the question poorly 🙂 ---
**Author:** ![simon1tan](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/9e8a1a/32.png) [@simon1tan](https://www.ruby-forum.com/u/simon1tan)\ **Post date:** [January 26, 2009, 1:08pm UTC](https://www.ruby-forum.com/t/gsub-n-n/158169/9 "2009-01-26T13:08:21Z")
On Jan 24, 2009, at 7:25 PM, Simon T. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Ok, I just realized I’ve been using p to print everything out! “Puts” > works a whole lot better. Doh! Thanks for all the help. Sorry for > phrasing the question poorly 🙂 > > – > Posted via [http://www.ruby-forum.com/](http://www.ruby-forum.com/). LOL! ---
**Author:** ![simon1tan](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/9e8a1a/32.png) [@simon1tan](https://www.ruby-forum.com/u/simon1tan)\ **Post date:** [January 20, 2009, 7:17pm UTC](https://www.ruby-forum.com/t/gsub-n-n/158169/10 "2009-01-20T19:17:54Z")
Simon T. wrote: > I’m not sure why but I assumed gsub! would allow me to replace > \n with line feeds “\n” _is_ a line feed. > > string = “hello\nworld” > > =\> “hello\nworld” > > > puts string > > hello > > world > > =\> nil HTH, Sebastian