Preventing string truncation with snprintf()

One issue with using snprintf() (the buffer-overrun-preventing version of sprintf()) is that since the size of the char[] we're trying to "print" into is limited, truncation would occur if the string is longer than the char[] size. Yet after studying the manual carefully, I noticed that snprintf() actually returns the length of the resultant string, regardless of the size of the buffer. Below is a simple demonstration of how to prevent truncation with this feature and dynamical allocation of the character buffer.

#include <stdio.h>
#include <stdlib.h>

int main(int argc, char *argv[])
{
   #define NC 10
   #define ALONGSTRING "A long string of nonsense that would've been truncated."

   size_t len;
   char *string = calloc(NC, sizeof(*string));

   len = snprintf(string, NC, ALONGSTRING);

   printf("Truncated string: '%s'\n", string);

   if(len >= NC) {
       string = realloc(string, (len + 1) * sizeof(*string));
       snprintf(string, len + 1, ALONGSTRING);
   }

   printf("Non-truncated string: '%s'\n", string);

   free(string);

   return 0;
}