sprintf-like function for CUDA device-side code?

Question

I could not find anything in internet. Due to the fact that it is possible to use printf in a __device__ function I am wondering if there is a sprintf like function due to the fact that printf is "using" the result from sprintf to be displayed in stdout.

Answer 1

No there isn't anything built into CUDA for this.

Within CUDA the implementation of device printf is a special case and does not use the same mechanisms as the C library printf.

Answer 2

sprintf(), snprintf() and additional printf()-family functions are now available on the development branch of the CUDA Kernel Author's Toolkit, a.k.a. cuda-kat. Signatures:

namespace kat {

__device__ int sprintf(char* s, const char* format, ...);
__device__ int snprintf(char* s, size_t n, const char* format, ...);

}

... and they do exactly what you would expect. In particular, they support the C standard features which CUDA printf() does not, and then some (e.g. specifying a string argument's field width using an extra argument; format specifiers for size_t, and ptrdiff_t, and printing in base-2).

Caveat: I am the author of cuda-kat, so I'm biased...

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_{Always prefer snprintf() which takes the buffer size oversprintf() which might overflow.}