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| Newsgroups | comp.std.c |
|---|---|
| Subject | Re: PRI* considered harmful |
| References | (3 earlier) <lntyaxztes.fsf@nuthaus.mib.org> <87oc15g10i.fsf@once.weird.com> <lnhb6xzmbf.fsf@nuthaus.mib.org> <87zkkpef5z.fsf@once.weird.com> <iv5qd4$f26$1@dont-email.me> |
| From | "Greg A. Woods" <woods@robohack.org> |
| Message-ID | <87mxgpe84b.fsf@once.weird.com> (permalink) |
| Date | 2011-07-07 20:58 -0700 |
James Kuyper <jameskuyper@verizon.net> writes:
>
> The right way to warn about mismatches: only warn when there's an actual
> mismatch.
It is an "actual" mis-match -- at least if you intend your code to be
portable.
> The right way to #define PRI32d: #define it to be a format specification
> which is NOT a mismatch for the corresponding promoted type; no cast
> required.
Someone should try this on some GNU/Linux variants for me -- I think
from my manual inspection of glibc header sources online that you'll get
a warning (if you turn on the right warning flags)....
It works OK on NetBSD and on OS X.
> The right way to use PRI32d (no cast required):
> int32_t value;
> // set value
> printf("value:%" PRI32d "\n", value);
Some code does that, but most folks don't seem to be PL/1-heads,
i.e. that pedantic about how many bits they want. Most folks want an
"int", or maybe a "long" for bigger values. They can't be bothered to
worry about numbers of bits.
> An implementation that can't be bothered to define the PRI* macros
> correctly cannot be trusted to implement your proposed printf()
> enhancements, either.
Sigh....
>>>> Also, I repeat, C99 strftime() is unable to print the value of a time_t
>>>> as an integer representation of seconds since the epoch of time_t. ...
>
> Well, of course not. For that you use
> printf("seconds since epoch:%.0f\n", difftime(value,epoch));
Decades of unix tradition flushed down the drain by C99. :-)
--
Greg A. Woods
RoboHack
<woods@robohack.ca> living on the edge http://www.robohack.ca/
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PRI* considered harmful "Greg A. Woods" <woods@robohack.org> - 2011-07-06 19:58 -0700
Re: PRI* considered harmful William Ahern <william@wilbur.25thandClement.com> - 2011-07-06 20:38 -0700
Re: PRI* considered harmful "Greg A. Woods" <woods@robohack.org> - 2011-07-06 22:26 -0700
Re: PRI* considered harmful Jens Gustedt <Jens.Gustedt@loria.fr> - 2011-07-07 08:52 +0200
Re: PRI* considered harmful "Greg A. Woods" <woods@robohack.org> - 2011-07-07 14:11 -0700
Re: PRI* considered harmful Jens Gustedt <Jens.Gustedt@loria.fr> - 2011-07-08 11:58 +0200
Re: PRI* considered harmful lawrence.jones@siemens.com - 2011-07-07 17:58 -0400
Re: PRI* considered harmful Jens Gustedt <Jens.Gustedt@loria.fr> - 2011-07-08 12:02 +0200
Re: PRI* considered harmful lawrence.jones@siemens.com - 2011-07-07 17:57 -0400
Re: PRI* considered harmful Keith Thompson <kst-u@mib.org> - 2011-07-07 15:42 -0700
Re: PRI* considered harmful lawrence.jones@siemens.com - 2011-07-08 08:56 -0400
Re: PRI* considered harmful James Kuyper <jameskuyper@verizon.net> - 2011-07-07 06:36 -0400
Re: PRI* considered harmful "Greg A. Woods" <woods@robohack.org> - 2011-07-07 12:59 -0700
Re: PRI* considered harmful Keith Thompson <kst-u@mib.org> - 2011-07-07 14:12 -0700
Re: PRI* considered harmful "Greg A. Woods" <woods@robohack.org> - 2011-07-07 15:49 -0700
Re: PRI* considered harmful Keith Thompson <kst-u@mib.org> - 2011-07-07 16:46 -0700
Re: PRI* considered harmful "Greg A. Woods" <woods@robohack.org> - 2011-07-07 18:26 -0700
Re: PRI* considered harmful James Kuyper <jameskuyper@verizon.net> - 2011-07-07 22:35 -0400
Re: PRI* considered harmful "Greg A. Woods" <woods@robohack.org> - 2011-07-07 20:58 -0700
Re: PRI* considered harmful Wojtek Lerch <wojtek_l@yahoo.ca> - 2011-07-08 00:28 -0400
Re: PRI* considered harmful James Kuyper <jameskuyper@verizon.net> - 2011-07-08 07:41 -0400
Re: PRI* considered harmful "Greg A. Woods" <woods@robohack.org> - 2011-07-08 23:05 -0700
Re: PRI* considered harmful Keith Thompson <kst-u@mib.org> - 2011-07-09 00:50 -0700
Re: [incorrectly implementd] PRI* considered harmful James Kuyper <jameskuyper@verizon.net> - 2011-07-09 06:38 -0400
Re: PRI* considered harmful Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2011-07-09 21:07 +0200
Re: PRI* considered harmful Keith Thompson <kst-u@mib.org> - 2011-07-08 09:52 -0700
Re: PRI* considered harmful Richard Kettlewell <rjk@greenend.org.uk> - 2011-07-08 11:45 +0100
Re: PRI* considered harmful "Greg A. Woods" <woods@robohack.org> - 2011-07-08 23:14 -0700
Re: PRI* considered harmful Keith Thompson <kst-u@mib.org> - 2011-07-09 00:47 -0700
Re: PRI* considered harmful Richard Kettlewell <rjk@greenend.org.uk> - 2011-07-09 10:51 +0100
Re: PRI* considered harmful James Kuyper <jameskuyper@verizon.net> - 2011-07-09 06:43 -0400
Re: PRI* considered harmful Keith Thompson <kst-u@mib.org> - 2011-07-08 09:49 -0700
Re: PRI* considered harmful "Greg A. Woods" <woods@robohack.org> - 2011-07-08 23:24 -0700
Re: PRI* considered harmful Keith Thompson <kst-u@mib.org> - 2011-07-09 00:45 -0700
Re: PRI* considered harmful "Greg A. Woods" <woods@robohack.org> - 2011-07-09 16:18 -0700
Re: PRI* considered harmful Keith Thompson <kst-u@mib.org> - 2011-07-09 18:57 -0700
Re: PRI* considered harmful Keith Thompson <kst-u@mib.org> - 2011-07-13 09:37 -0700
Re: PRI* considered harmful James Kuyper <jameskuyper@verizon.net> - 2011-07-09 06:46 -0400
Re: PRI* considered harmful Harald van Dijk <truedfx@gmail.com> - 2011-07-09 08:09 -0700
Re: PRI* considered harmful Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-07-11 16:00 +0300
Re: PRI* considered harmful Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2011-07-09 20:59 +0200
Re: PRI* considered harmful Keith Thompson <kst-u@mib.org> - 2011-07-09 12:22 -0700
Re: PRI* considered harmful Hans-Bernhard Bröker <HBBroeker@t-online.de> - 2011-07-09 21:32 +0200
Re: PRI* considered harmful Keith Thompson <kst-u@mib.org> - 2011-07-09 12:54 -0700
Re: PRI* considered harmful Marcin Grzegorczyk <mgrzegor@poczta.onet.pl> - 2011-07-09 23:39 +0200
Re: PRI* considered harmful "Greg A. Woods" <woods@robohack.org> - 2011-07-09 16:56 -0700
Re: PRI* considered harmful "Greg A. Woods" <woods@robohack.org> - 2011-07-09 16:52 -0700
Re: PRI* considered harmful Keith Thompson <kst-u@mib.org> - 2011-07-09 18:53 -0700
Re: PRI* considered harmful Jens Gustedt <Jens.Gustedt@loria.fr> - 2011-07-10 14:12 +0200
Re: PRI* considered harmful Marcin Grzegorczyk <mgrzegor@poczta.onet.pl> - 2011-07-11 20:22 +0200
Re: PRI* considered harmful Jens Gustedt <Jens.Gustedt@loria.fr> - 2011-07-10 13:57 +0200
Re: PRI* considered harmful "Greg A. Woods" <woods@robohack.org> - 2011-07-09 16:49 -0700
Re: PRI* considered harmful Jens Schweikhardt <usenet@schweikhardt.net> - 2011-07-19 19:28 +0000
Re: PRI* considered harmful Tim Rentsch <txr@alumni.caltech.edu> - 2011-07-07 14:13 -0700
Re: PRI* considered harmful Keith Thompson <kst-u@mib.org> - 2011-07-09 01:04 -0700
Re: PRI* considered harmful "Greg A. Woods" <woods@robohack.org> - 2011-07-09 17:23 -0700
Re: PRI* considered harmful Keith Thompson <kst-u@mib.org> - 2011-07-09 19:03 -0700
Re: PRI* considered harmful Marcin Grzegorczyk <mgrzegor@poczta.onet.pl> - 2011-07-11 20:40 +0200
Re: PRI* considered harmful Keith Thompson <kst-u@mib.org> - 2011-07-11 11:56 -0700
Re: PRI* considered harmful Marcin Grzegorczyk <mgrzegor@poczta.onet.pl> - 2011-07-11 21:40 +0200
Re: PRI* considered harmful Keith Thompson <kst-u@mib.org> - 2011-07-11 13:16 -0700
Re: PRI* considered harmful Marcin Grzegorczyk <mgrzegor@poczta.onet.pl> - 2011-07-11 23:29 +0200
Re: PRI* considered harmful Keith Thompson <kst-u@mib.org> - 2011-07-11 14:46 -0700
Re: PRI* considered harmful "Greg A. Woods" <woods@robohack.org> - 2011-07-12 22:18 -0700
Re: PRI* considered harmful Keith Thompson <kst-u@mib.org> - 2011-07-13 09:00 -0700
Re: PRI* considered harmful Richard Kettlewell <rjk@greenend.org.uk> - 2011-07-09 20:30 +0100
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