Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
| From | Patrick Scheible <kkt@zipcon.net> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: trigraphs, yecch |
| References | <4f2808f4.648026530@text.giganews.com> <ln4nvbxxkb.fsf@nuthaus.mib.org> |
| Date | 2012-01-31 17:01 -0800 |
| Message-ID | <86aa53e59d.fsf@zipcon.net> (permalink) |
| Organization | The Zip Connection (zipcon.net) |
Keith Thompson <kst-u@mib.org> writes:
> cri@tiac.net (Richard Harter) writes:
>> The other day I wanted to put three successive question marks in a
>> string. Frex, "(???).%s.%s". My trusty antique gcc compiler
>> converted the last two '?'s into a ']' along with a warning that it
>> was doing a trigraph conversion.
>>
>> Now, me, I know from nothing about trigraphs - never used them, hope
>> never to use them - so I was caught by surprise. My elderly copy of
>> K&R described them but I didn't see anything about getting around
>> them.
>>
>> So. How is one supposed to get three successive question marks into a
>> string?
>
> For reference, there are exactly 9 trigraphs. C99 5.2.1.1:
>
> All occurrences in a source file of the following sequences of three
> characters (called trigraph sequences) are replaced with the
> corresponding single character.
>
> ??= # ??) ] ??! |
> ??( [ ??' ^ ??> }
> ??/ \ ??< { ??- ~
>
> No other trigraph sequences exist. Each ? that does not begin one of
> the trigraphs listed above is not changed.
>
> In your case, "???" is not a trigraph, but ??) is.
Has the C standards committee been flamed enough for trigraphs? I don't
think so. I bet there's 1000 programmers bitten by them for every 1
who's been helped. By 1989 anyone who didn't have an editor capable of
typing any 7-bit ASCII character was a hopeless luddite who would be
better served making their own pre-preprocessing phase for C and leaving
the language unchanged instead of another phase in the preprocessor for
every C program forever and ever.
-- Patrick
Back to comp.lang.c | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
trigraphs, yecch cri@tiac.net (Richard Harter) - 2012-01-31 15:55 +0000
Re: trigraphs, yecch pete <pfiland@mindspring.com> - 2012-01-31 11:05 -0500
Re: trigraphs, yecch Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-01-31 16:47 +0000
Re: trigraphs, yecch cri@tiac.net (Richard Harter) - 2012-01-31 17:21 +0000
Re: trigraphs, yecch James Kuyper <jameskuyper@verizon.net> - 2012-01-31 12:26 -0500
Re: trigraphs, yecch Robert Wessel <robertwessel2@yahoo.com> - 2012-01-31 11:40 -0600
Re: trigraphs, yecch Keith Thompson <kst-u@mib.org> - 2012-01-31 15:22 -0800
Re: trigraphs, yecch "BartC" <bc@freeuk.com> - 2012-02-01 01:09 +0000
Re: trigraphs, yecch James Kuyper <jameskuyper@verizon.net> - 2012-01-31 22:21 -0500
Re: trigraphs, yecch Keith Thompson <kst-u@mib.org> - 2012-01-31 21:25 -0800
Re: trigraphs, yecch "Charles Richmond" <netnews@aquaporin4.com> - 2012-01-31 23:40 -0600
Re: trigraphs, yecch Keith Thompson <kst-u@mib.org> - 2012-01-31 22:19 -0800
Re: trigraphs, yecch James Kuyper <jameskuyper@verizon.net> - 2012-02-01 08:27 -0500
Re: trigraphs, yecch Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-01-31 17:47 +0000
Re: trigraphs, yecch ImpalerCore <jadill33@gmail.com> - 2012-01-31 09:41 -0800
Re: trigraphs, yecch pete <pfiland@mindspring.com> - 2012-01-31 13:17 -0500
Re: trigraphs, yecch blp@cs.stanford.edu (Ben Pfaff) - 2012-01-31 09:56 -0800
Re: trigraphs, yecch Peter Nilsson <airia@acay.com.au> - 2012-01-31 13:55 -0800
Re: trigraphs, yecch Harald van Dijk <haraldvdijk@gmail.com> - 2012-01-31 14:02 -0800
Re: trigraphs, yecch blp@cs.stanford.edu (Ben Pfaff) - 2012-01-31 14:06 -0800
Re: trigraphs, yecch Harald van Dijk <haraldvdijk@gmail.com> - 2012-01-31 15:13 -0800
Re: trigraphs, yecch "Charles Richmond" <netnews@aquaporin4.com> - 2012-01-31 23:44 -0600
Re: trigraphs, yecch Keith Thompson <kst-u@mib.org> - 2012-01-31 22:20 -0800
Re: trigraphs, yecch James Harris <james.harris.1@googlemail.com> - 2012-01-31 22:56 -0800
Re: trigraphs, yecch Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-02-01 12:15 +0000
Re: trigraphs, yecch Keith Thompson <kst-u@mib.org> - 2012-01-31 15:27 -0800
Re: trigraphs, yecch Patrick Scheible <kkt@zipcon.net> - 2012-01-31 17:01 -0800
Re: trigraphs, yecch Keith Thompson <kst-u@mib.org> - 2012-01-31 19:50 -0800
Re: trigraphs, yecch Patrick Scheible <kkt@zipcon.net> - 2012-02-01 10:31 -0800
Re: trigraphs, yecch James Kuyper <jameskuyper@verizon.net> - 2012-01-31 23:17 -0500
Re: trigraphs, yecch "Joachim Schmitz" <nospam.jojo@schmitz-digital.de> - 2012-02-01 10:39 +0100
Re: trigraphs, yecch Kaz Kylheku <kaz@kylheku.com> - 2012-02-01 17:20 +0000
Re: trigraphs, yecch Patrick Scheible <kkt@zipcon.net> - 2012-02-01 11:11 -0800
Re: trigraphs, yecch "Charles Richmond" <netnews@aquaporin4.com> - 2012-01-31 23:50 -0600
Re: trigraphs, yecch ralph <nt_consulting64@yahoo.net> - 2012-02-01 11:56 -0600
Re: trigraphs, yecch Patrick Scheible <kkt@zipcon.net> - 2012-02-01 11:12 -0800
Re: trigraphs, yecch Stephen Sprunk <stephen@sprunk.org> - 2012-02-01 13:29 -0600
Re: trigraphs, yecch blp@cs.stanford.edu (Ben Pfaff) - 2012-02-01 11:35 -0800
Re: trigraphs, yecch Kaz Kylheku <kaz@kylheku.com> - 2012-02-01 19:59 +0000
Re: trigraphs, yecch blp@cs.stanford.edu (Ben Pfaff) - 2012-02-01 12:41 -0800
Re: trigraphs, yecch Kaz Kylheku <kaz@kylheku.com> - 2012-02-01 22:55 +0000
Re: trigraphs, yecch Stephen Sprunk <stephen@sprunk.org> - 2012-02-01 14:44 -0600
Re: trigraphs, yecch Kaz Kylheku <kaz@kylheku.com> - 2012-02-01 22:55 +0000
Re: trigraphs, yecch "christian.bau" <christian.bau@cbau.wanadoo.co.uk> - 2012-02-02 14:19 -0800
Re: trigraphs, yecch Patrick Scheible <kkt@zipcon.net> - 2012-02-06 20:40 -0800
Re: trigraphs, yecch "Joachim Schmitz" <nospam.jojo@schmitz-digital.de> - 2012-02-07 11:40 +0100
Re: trigraphs, yecch jgk@panix.com (Joe keane) - 2012-02-02 14:15 +0000
Re: trigraphs, yecch cri@tiac.net (Richard Harter) - 2012-02-01 16:52 +0000
csiph-web