vsnprintf
There are 3 repositories under vsnprintf topic.
charlesnicholson/nanoprintf
The smallest public printf implementation for its feature set.
mysterywolf/rt_vsnprintf_full
rt_vsnprintf完整功能版本 | Fully functional version of rt_vsnprintf
klux21/callback_printf
callback_printf allows the implementation of portable sprintf, snprintf, vsprintf and vsnprintf like output functions. The code includes wrappers for those functions. It supports all formats of the C 11 standard. wchar_t arguments and strings are printed as UTF-8. It's pretty fast, threadsafe and has no dependencies to other libraries.