snprintf: identical to sprintf() except that a maximum of num-1 characters will be stored
//Header file: #include <stdio.h>
//Declaration: int snprintf(char * restrict buf, size_t num, const char * restrict format, ...)
#include <stdio.h>
int main ()
{ char buffer [50]; int n, a=5, b=3;
n=snprintf (buffer, 5,"%d plus %d is %d", a, b, a+b);
printf ("[%s] is a %d char long string\n",buffer,n); return 0;
}