Gordon,
Date: Mon, 22 Feb 2016 08:56:54 -0800
From: Gordon Messmer <gordon.messmer(a)gmail.com>
To: users(a)lists.fedoraproject.org
Subject: Re: Bash / Escaping quotes is driving me crazy . .
Message-ID: <56CB3DD6.2020909(a)gmail.com>
Content-Type: text/plain; charset=utf-8; format=flowed
On 02/20/2016 07:18 PM, Philip Rhoades wrote:
> OK, that all makes sense but there is a further issue - I was trying
> to keep it simple - this whole line is inside a Ruby "system" command
> ie:
> system( "ssh .. " )
> I can't use the second option because I need to use double quotes so
> that I can use Ruby variables inside the double quotes eg:
I think you're still missing some fundamental concepts about nesting
quotes. (I was also mistaken in suggesting that the wildcards needed
escaping when the internal double-quotes were escaped, though, so...
We
all make mistakes.)
In Ruby double-quoted strings, you can get interpolation, and in single
quoted strings you don't. But if you nest single quotes inside a
double-quoted strings, Ruby still treats the entire string as double
quoted. It doesn't change the rules when it finds single quotes inside
the double-quoted string, because they're merely a part of the
double-quoted string. So your options are:
system("ssh localhost \"find /home/... -maxdepth 1 -type f \\\\( -name
\\\"*.mp3\\\" -o -name \\\"*.m4a\\\" -o -name
\\\"*.flac\\\" \\\\)\" ")
or:
system("ssh localhost 'find /home/... -maxdepth 1 -type f \\( -name
\"*.mp3\" -o -name \"*.m4a\" -o -name \"*.flac\" \\)'
")
Using single quotes means significantly less escaping, and you can
still
use interpolation in any part of that string, in Ruby.
From another response, what I have actually ended up with is:
system("ssh localhost 'find /home/... -maxdepth 1 -type f \\( -name
\*.mp3 -o -name \*.m4a -o -name \*.flac \\)' ")
Thanks!
Phil.
--
Philip Rhoades
PO Box 896
Cowra NSW 2794
Australia
E-mail: phil(a)pricom.com.au