From: "Esteban Manchado Velázquez" <zoso@...>
Date: 2006-10-09T21:05:19+09:00
Subject: Re: gsub and slash-ampersand in the substitution string

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On Mon, Oct 09, 2006 at 08:58:09PM +0900, Jani Patokallio wrote:
> Greetings,
>=20
> I'm trying to do something that should be very simple: stick a "\" in=20
> front of
> every instance of "&" in a string.  However, the obvious code...
>=20
>   "this&that".gsub!("&", "*")
>   --> "this*that" # OK!
>=20
>   "this&that".gsub!("&", "\\&")
>   --> "this&that" # Wrong
>=20
> ...doesn't work, because "\&" means "last match" in gsub substitution=20
> strings.
> How can I escape this?  I experimentally determined that entering=20
> "\\\\\\&"
> (that's six backslashes) gets the desired result, but I don't really
> understand why.  Is there a less obscure way of doing this?

    I'm not sure, but I think that the problem is that you are using double
quotes. So, the value you are passing is really the same as:

    '\\\&'

Which, once you interpret the escape sequences, you have a literal '\' and a
literal '&'...

--=20
Esteban Manchado Vel=E1zquez <zoso@foton.es> - http://www.foton.es
EuropeSwPatentFree - http://EuropeSwPatentFree.hispalinux.es

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