Re: [vox-tech] String concatenation limit in C?

[Micah Cowan <MAPSmicah@cowanbox.com>]

On Thu, Jul 12, 2001 at 10:25:50PM -0700, Mark K. Kim wrote:
> Hey gang!
> 
> If you have a code like this in C:
> 
>    printf(
>       "Hello, world #1\n"
>       "Hello, world #2\n"
>       "Hello, world #3\n"
>    );
> 
> this eventually gets translated to (either by the compiler or the
> preprocessor, I'm not sure):
> 
>    printf("Hello, world #1\nHello, world #2\nHello, world #3\n");
> 
> My question is whether there is a limit to how many of these
> concatenations the compiler or the preprocessor will do, and whether there
> is a limit to the total length of the strings before the concatenation and
> after the concatenation.

No limits at all.  This is a good technique for breaking up strings,
and is fairly common among comp.lang.c regulars.  There is no limit to
the total length of the strings, except for whatever the
implementation's limit on objects in general is.

> Does anyone have the ANSI C document? :)  

I have the 'official' standard for the most recent version of C,
ISO/IEC 9899:1999, but there are no complete implementations of that
yet, unfortunately, though several compilers (including the new GCC
3.0 combined with glibc 2.2) implement a substantial subset.  Some
/really/ kewl features - I can't wait 'til they're commonplace, but I
daren't write C99 code until there are a number of fully conforming
implementations.

But, of course, I can't legally give you that.  You can get a copy of
the last public draft, but be warned that there are a number of
significant differences.

I also have the last public draft of the version of C which is most
widely implemented at the moment, apparently including the 1995
revisions.  I haven't found any problems using that as a reference, so
it should be good.  I'd be glad to send that to you if you'd like.

Micah