How to pass variable length width specifier in sscanf?

Question

sscanf(input_str, \"%5s\", buf); //reads at max 5 characters from input_str to buf

But I need to use something like %MACRO_SIZEs instead of %5s

Answer 1

if your MACRO_SIZE is const at compile time, you can try this:

#define MACRO_SIZE "5"
snprintf(fmt_str, 100, "%" MACRO_SIZE "s", buf);