Date: Wed, 26 Jan 2005 12:36:33 +0200 From: Giorgos Keramidas <keramida@ceid.upatras.gr> To: Steven Smith <sos22@cantab.net> Cc: sos22@srcf.ucam.org Subject: Re: Dubious #define in include/pwd.h Message-ID: <20050126103633.GA829@orion.daedalusnetworks.priv> In-Reply-To: <20050126100839.GA4367@archibold> References: <20050125214606.GB1113@archibold> <20050126004033.GA2640@gothmog.gr> <20050126100839.GA4367@archibold>
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On 2005-01-26 10:08, Steven Smith <sos22@cantab.net> wrote:
>>> I was messing around with sparse, the static checker used sometimes
>>> by Linux kernel people, and I (or rather, it) came upon the line
>>>
>>> #define _PW_VERSION_MASK '0xF0'
>>>
>>> in /usr/src/include/pwd.h. I can't immediately see any use for this;
>>> '\xf0' would probably be more useful.
>>
>> If this is used as a mask for 'unsigned char' values, why would it make
>> any difference? Aren't they both going to be implicitly converted to
>> the right typep anyway?
>
> Well, except for the single quotes around '0xf0'. If you go:
>
> int x = '0xf0';
> printf("%d\n", x);
>
> you probably won't get what you expect. If you replace the '0xf0'
> with '\xf0' you probably will.
Oops. You're right. I somehow managed to ignore the quotes :-)
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