why doesn't sprintf( ) work?

Mike P wrote:
>sprintf( ) doesn't work.  strcpy & strcat work fine.  i suspect there's
>a library initialization that isn't being called for some reason.

Is there enough stack-space available? Is the heap initilalized? Does 
the linker set the "end"-symbol correctly?

>the code worked fine when i used the keil compiler.
>sprintf(s, "Day %d", 1)

I expect you do not use the "Keil compiler" (very outdated) but the 
Realview toolchain which comes with MDK-ARM but this will not help 
anyway. The interfaces for stdio functions like sprintf are standardized 
but the implementions are different.

> i have looked for the source for sprintf but have never found it.
> truthfully, i'm also not sure i'm looking in the right place.

stio-functions like sprintf are part of the libc. Most binary 
disitributions for the GNU ARM-cross-toolchain use the newlib as libc. 
If you are using such a package you will find the sources in the newlib 
CVS: 
http://sourceware.org/cgi-bin/cvsweb.cgi/src/newlib/libc/stdio/?cvsroot=src

>I imagine i should be looking at http://www.gnu.org .  i found some
>source but never managed to find what i'm looking for.

As far as I know the compiler can replace calls to sprintf which only 
use constant parameters which something like memcopy if optimization is 
enabled. Maybe you have found code for this in the gcc-sources but it 
will not help with non-constant parameters.