From: "Jérémie Roquet" <arkanosis@gmail.com>
To: Sebastian Stark <seb-zsh@biskalar.de>
Cc: zsh-users@zsh.org
Subject: Re: double quoted expansion question
Date: Fri, 7 Sep 2012 14:47:08 +0200 [thread overview]
Message-ID: <CAFOazANjtNgy23x+1hPKsQ2hKDTQc2RwF2STU5baszFmX95XNw@mail.gmail.com> (raw)
In-Reply-To: <29236168-55B5-4555-9ACA-B1D21D345EA9@biskalar.de>
Hi,
2012/9/7 Sebastian Stark <seb-zsh@biskalar.de>:
> I am trying to make a unique list of tags that is given in a string with a certain format, e. g.:
>
> servers="
> madeira linux,gpu,users
> madeira2 linux,gpu,users
> smtp linux,mail,smtp
> isar linux,users
> easygwa linux,web,external
> "
>
> The format is: server name, space, tag, comma, tag, comma, tag ...
>
> What I want from the above list is this:
>
> external gpu linux mail smtp users web
>
> and I get it with:
>
> print ${(s:,:uo)${(j:,:)${${(f)servers}//* /}}}
>
> However, if I do this:
>
> print "${(s:,:uo)${(j:,:)${${(f)servers}//* /}}}"
>
> I get:
>
> external linux web
>
> This also happens when I use the variable expansion expression in a here document, which, I suppose, is undergoing the same treatment as double quoted strings.
>
> What I would like to understand here is why the output changes the way it does when I add double quotes around my expression. I would expect the same output as without. If anybody could shed some light please, I guess it's just something obvious I cannot see.
I'm not 100 % sure, but I suppose the quotes prevents the shell from
splitting your string on $IFS, so you only have *one* string, and the
“//* /" expression suppresses everything before the last space,
leaving only the tags of the last line.
Best regards,
--
Jérémie
next prev parent reply other threads:[~2012-09-07 12:55 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-07 12:31 Sebastian Stark
2012-09-07 12:47 ` Jérémie Roquet [this message]
2012-09-07 12:54 ` Jérémie Roquet
2012-09-07 14:36 ` Sebastian Stark
2012-09-07 14:41 ` Bart Schaefer
2012-09-07 15:43 ` Sebastian Stark
2012-09-08 5:38 ` Bart Schaefer
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