snprintf − Format a string and place it in a buffer
int snprintf(char * buf, size_t size, const char * fmt, ...);
char * buf
The buffer to place the result into
The size of the buffer, including the trailing null space
const char * fmt
The format string to use
Arguments for the format string
The return value is the number of characters which would be generated for the given input, excluding the trailing null, as per ISO C99. If the return is greater than or equal to size, the resulting string is truncated.
See the vsnprintf documentation for format string extensions over C99.