see what happens

strtest.c

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

int main(int argc, char* argv[]) {
  char *src="12345678";
  char dst1[10];
  char dst2[10];

  // ensure that dst is clean
  memset(dst1, '\0', 10);
  memset(dst2, '\0', 10);

  strcpy(dst1, src);
  strncpy(dst2, src, 8);

  printf("Source: %s\nResult 1: %s\nResult 2: %s\n", src, dst1, dst2);

  return 0;
}