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Date:      Sat, 6 Jan 2018 17:03:52 +0100
From:      Polytropon <freebsd@edvax.de>
To:        Victor Sudakov <vas@mpeks.tomsk.su>
Cc:        Ultima <ultima1252@gmail.com>, Polytropon <freebsd@edvax.de>, FreeBSD Mailing List <freebsd-questions@freebsd.org>
Subject:   Re: Convert .flac and .ape to mp3
Message-ID:  <20180106170352.ce49b320.freebsd@edvax.de>
In-Reply-To: <20180106150753.GA35605@admin.sibptus.transneft.ru>
References:  <20180104163421.GA15692@admin.sibptus.transneft.ru> <20180104175156.440fa0c2.freebsd@edvax.de> <20180106063934.GA32231@admin.sibptus.transneft.ru> <CANJ8om7LJqAG+X0dn1JDZn1WYJtxZtX9SAK2yQU74om7-SSQRQ@mail.gmail.com> <20180106085528.GA33117@admin.sibptus.transneft.ru> <CANJ8om7zUoLM9HCB_5rzC9uWRaPRhCNKcS4-WsXyjZOGGKwDig@mail.gmail.com> <CANJ8om4W7JTxSYxrLjxkDjDVE8b6CxBcOwPV+PMQ-oQJYuNW9g@mail.gmail.com> <20180106150753.GA35605@admin.sibptus.transneft.ru>

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On Sat, 6 Jan 2018 22:07:53 +0700, Victor Sudakov wrote:
> Ultima wrote:
> > Actually, that wont work either. I decided to go look at some of my scripts
> > where I had to do something similar, the solution was setting IFS.
> > 
> > IFS=$'\n'
> 
> What's the dollar sign here for? Why not IFS='\n'?

It can be seen as "evaluation symbol" (as known from $FOO
being "FOO evaluated"), or "value of" ($FOO = the value
of FOO).

Another way (convenient, but doesn't look good" is to do
something like this:

IFS="
"

This is a newline as well. In the case above, you want to
set IFS to an _actual_ newline, not to \n. Remember _when_
the shell evaluates something: Variables like $IFS will
be evaluated when being accessed, not when they are being
declared (even with an initial value). The $'\n' makes
sure that IFS will be assigned an actual (non-escaped)
newline, so when constructs like for() or while read
access $IFS, they find a "real" newline there.

With the same idea in mind, you sometimes find things
like this:

IFS="`printf '\n'`"

I think it becomes perfectly clear now: IFS is assigned
the _result_ of _printing_ a \n.

At least that's how my dusty brain seems to remember... ;-)




-- 
Polytropon
Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...



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