Path: csiph.com!eternal-september.org!feeder.eternal-september.org!mx02.eternal-september.org!.POSTED!not-for-mail
From: Keith Thompson <kst-u@mib.org>
Newsgroups: comp.lang.c
Subject: Re: Working efficiently with 32-bit Unicode output streams, locale etc.
Date: Tue, 01 Dec 2015 12:53:57 -0800
Organization: None to speak of
Lines: 52
Message-ID: <lnpoypubyy.fsf@kst-u.example.com>
References: <n3dfgs$a24$1@speranza.aioe.org> <dbv9quFea62U7@mid.individual.net> <0407abc1-4ce3-4213-91f2-987a3620bbc8@googlegroups.com> <n3echd$qaj$1@dont-email.me> <834d72b5-230d-4ff6-a558-5885932e6b6b@googlegroups.com> <n3g5eq$pvg$1@speranza.aioe.org> <dc1l2pF2cb8U1@mid.individual.net> <n3g77s$sor$1@speranza.aioe.org> <dc1m91F2cb8U2@mid.individual.net> <n3g921$vlq$1@speranza.aioe.org> <e037cc57-2024-491d-a992-8e821cd8014b@googlegroups.com> <n3h61a$v9h$1@dont-email.me> <n3hejb$ujn$1@dont-email.me> <lnh9k3w59i.fsf@kst-u.example.com> <n3iil7$ld7$1@dont-email.me> <n3j2ke$3do$1@dont-email.me> <n3k48m$9j6$1@dont-email.me> <87a8pudybv.fsf@bsb.me.uk> <21078681-254f-4af6-8f17-9e967a409f28@googlegroups.com> <dc6ddnFi96mU3@mid.individual.net> <n3l0hk$u87$1@dont-email.me>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 8bit
Injection-Info: mx02.eternal-september.org; posting-host="945944de09706c9b4e29b53c9d2efdc2"; logging-data="1467"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX1++U8ocdtE5elXYXAhEufXN"
User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.1 (gnu/linux)
Cancel-Lock: sha1:+SsybjcGntATnkYO1DS7zxwpR1w= sha1:9cUStaFPn+mMrzBNyQAEjB+Lfis=
Xref: csiph.com comp.lang.c:77569

BartC <bc@freeuk.com> writes:
[...]
> If I run this code, where it prints the first 4 'somethings' of the string:
>
>      printf("%.4s","£100pw");
>
> Then it outputs "£10" in UTF8, not "£100". £90 is a big difference!

The pound sign in your article is printed in my newsreader (actually in
GNU Emacs) as \243.  Your article headers include:

    Content-Type: text/plain; charset=windows-1252; format=flowed

Apparently my system (I'm using Linux) isn't configured to understand
windows-1252, so it falls back to displaying the character in octal.

I see you're using Thunderbird on Windows.  Is there any way you can
configure it to post using UTF-8?

Anyway ...

> So does that 4 represent bytes or characters?
>
> The specs for printf on MSDN say printf returns the number of characters 
> printed, while the C standard says it's the number of characters 
> transmitted.
>
> But here it returns 4 for an output of "£10", clearly not 4 characters. 
> So it's all a bit of a mess.

The C standard says that printf returns "the number of characters
transmitted, or a negative value if an output or encoding error
occurred".

It appears to be using the word "character" in the sense defined in
3.7.1:

    character
    single-byte character
    <C> bit representation that fits in a byte

as opposed to 3.7:

    character
    <abstract> member of a set of elements used for the organization,
    control, or representation of data

-- 
Keith Thompson (The_Other_Keith) kst-u@mib.org  <http://www.ghoti.net/~kst>
Working, but not speaking, for JetHead Development, Inc.
"We must do something.  This is something.  Therefore, we must do this."
    -- Antony Jay and Jonathan Lynn, "Yes Minister"