From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <zsh-workers-return-35141-mason-zsh=primenet.com.au@zsh.org>
Received: (qmail 24006 invoked by alias); 14 May 2015 23:24:17 -0000
Mailing-List: contact zsh-workers-help@zsh.org; run by ezmlm
Precedence: bulk
X-No-Archive: yes
List-Id: Zsh Workers List <zsh-workers.zsh.org>
List-Post: <mailto:zsh-workers@zsh.org>
List-Help: <mailto:zsh-workers-help@zsh.org>
X-Seq: 35141
Received: (qmail 11787 invoked from network); 14 May 2015 23:24:12 -0000
X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on f.primenet.com.au
X-Spam-Level: 
X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_LOW,
	SPF_HELO_PASS autolearn=ham version=3.3.2
X-Injected-Via-Gmane: http://gmane.org/
Mail-Followup-To: zsh-workers@zsh.org
To: zsh-workers@zsh.org
From: Emanuel Berg <embe8573@student.uu.se>
Subject: Re: why do ceil/floor give the decimal dot?
Date: Fri, 15 May 2015 01:29:18 +0200
Message-ID: <87d22220xd.fsf@debian.uxu>
References: <87oalodmns.fsf@debian.uxu>
	<150513195617.ZM29493@torch.brasslantern.com> <87d223et0a.fsf@debian.uxu>
	<B6914C0C-15CA-4FE2-A21A-4320D4CD4927@larryv.me>
	<20150514105349.52338d94@pwslap01u.europe.root.pri>
	<87siay262s.fsf@debian.uxu>
	<14C892AF-61F9-4FEE-832C-0AD196669182@larryv.me>
Mime-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 8bit
X-Complaints-To: usenet@ger.gmane.org
X-Gmane-NNTP-Posting-Host: nl106-137-66.student.uu.se
Mail-Copies-To: never
User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.4 (gnu/linux)
Cancel-Lock: sha1:rIZXADw4Gw07bKUSANdYJqzWYnw=

Lawrence Velázquez <vq@larryv.me> writes:

>> I like the solution better to have the types all
>> floats (or whatever) and then use printf to make it
>> look the way you want.
>
> You should use %g then (with appropriate precision)
> because %d does an implicit conversion.
>
>     % printf '%d\n' $(( 1e20 ))
>     -9223372036854775808
>
>     % printf '%g\n' $(( 1e20 ))
>     1e+20
>
>     % printf '%.30g\n' $(( 1e20 ))
>     100000000000000000000

OK, case closed:

    prefix-len () {
        local hosts=$1
        local len=$(( 32 - ceil(log($hosts)/log(2)) ))
        printf "%g\n" $len
    }

    $ prefix-len 30
    27

Thanks everyone.

-- 
underground experts united
http://user.it.uu.se/~embe8573