snprintf

The BSD man page mentions that snprintf may not be safe for use in signal handlers on some systems; obviously snprintf is a much bigger piece of code.

The correct solution, assuming you can't just import libbsd or include its functions, is probably to use snprintf.

Their maximum size is usually known and all called functions take a size argument (snprintf(), strftime(), strlcpy(), etc.).

And Visual Studio 2014 added most of the missing pieces, including a standards compliant snprintf.

The C99 Standard Library has been completed in 2015, including snprintf, with the exceptions noted in my post (tgmath.h and pragma macros).

Yeah, but as soon as you use snprintf you're throwing performance to the wind.

Yes, it uses lots of strcpy and sprintf instead of strncpy, snprintf or strlcpy.

I'm not a C programmer, but even I knew that strlcpy() and snprintf() would come up in this discussion.

What sort of C programmer wouldn't use snprintf to do the formatting?

Just call snprintf() even in such cases and forget about sprintf().

Yeah- implicit concatenation + snprintf seems like the way to go.

PyOS_snprintf(buf, buflen, fmt, -x); The native snprintf is heavier because it handles precision, zero-padding and stuff like that.

Starting in C99, you can do this: snprintf(buffer, size, "%s", source); This can be put into a #define macro or inline function.

So strncpy(dst, src, size_dst); becomes snprintf(dst, size_dst, "%s", src); Checking for partial copy is not ideal though, snprintf returns the number of bytes it would have copied had the destination buffer been infinite excluding the final NUL byte.

Snprintf, implemented as a library function, is also a lot (like 1000x) slower than strcpy; however, I don't condone use of strcpy.