From: Rich Felker <dalias@libc.org>
To: musl@lists.openwall.com
Subject: Re: printf doesn't respect locale
Date: Tue, 10 Sep 2019 13:33:51 -0400 [thread overview]
Message-ID: <20190910173351.GR9017@brightrain.aerifal.cx> (raw)
In-Reply-To: <CAPy=dbLiUm_H22myz9LBkiSVv+4vv0B7t5RMD+i=mDWYeqJ=pg@mail.gmail.com>
On Tue, Sep 10, 2019 at 06:10:20PM +0100, Daniel Schoepe wrote:
> Basically, someone used printf to produce json output and was unaware
> that the radix used by printf was locale-dependent. When this was run
> on a system with a non-English locale, it no longer produced valid
> JSON as output.
Yes, like you say it's not really a bug in correct software so much as
a pitfall programmers are unaware of, that's hard to program around.
But it can actually be a bug in correct *application* software due to
incorrect library software. Various library software (I think glib or
gtk, IIRC, among many others) calls setlocale(LC_ALL,"") behind the
application's back, rather than trusting that the application set the
locale the way it wants (incidentially, this is not thread-safe or
library-safe and makes these libraries unsafe to use via dlopen or
anywhere but at the top of main!). If the application only intends to
set other categories, but leave LC_NUMERIC as "C", then it should
rightfully expect a '.' radix point, but this expectation will be
violated if certain third-party libraries are involved.
Rich
> On Tue, Sep 10, 2019 at 5:31 PM Szabolcs Nagy <nsz@port70.net> wrote:
> >
> > * Daniel Schoepe <daniel@schoepe.org> [2019-09-10 17:00:49 +0100]:
> > > I'm also not a fan of this behavior, I actually stumbled across this
> > > when tracking
> > > down a bug the different radix usage caused.
> >
> > i'm interested in how this can cause a bug in correct software.
next prev parent reply other threads:[~2019-09-10 17:33 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-09 16:31 Daniel Schoepe
2019-09-09 16:39 ` Daniel Schoepe
2019-09-09 16:51 ` Szabolcs Nagy
2019-09-09 17:55 ` Rich Felker
2019-09-09 17:54 ` Rich Felker
2019-09-10 16:00 ` Daniel Schoepe
2019-09-10 16:31 ` Szabolcs Nagy
2019-09-10 16:44 ` Tim Tassonis
2019-09-10 17:30 ` Rich Felker
2019-09-10 17:10 ` Daniel Schoepe
2019-09-10 17:33 ` Rich Felker [this message]
2019-09-10 18:43 ` Szabolcs Nagy
2019-09-10 21:55 ` A. Wilcox
2019-09-11 10:01 ` Szabolcs Nagy
2019-09-11 10:07 ` Jens Gustedt
2019-09-11 11:44 ` Rich Felker
2019-09-11 12:53 ` Jens Gustedt
2019-09-11 13:47 ` Rich Felker
2019-09-11 15:15 ` Jens Gustedt
2019-09-11 15:38 ` Rich Felker
2019-09-11 18:08 ` Jens Gustedt
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