C语言 strncpy()函数

char *strncpy(char *str1, const char *str2, size_t n)

#include <stdio.h>
#include <string.h>
int main () {
   char str1[20]; 
   char str2[25];
   /* The first argument in the function is destination string. 
    * In this case we are doing full copy using the strcpy() function. 
    * Here string str2 is destination string in which we are copying the 
    * specified string 
    */ 
   strcpy(str2, "welcome to beginnersbook.com");

   /* In this case we are doing a limited copy using the strncpy()
    * function. We are copying only the 7 characters of string str2 to str1
    */
   strncpy(str1, str2, 7);

   printf("String str1: %s\n", str1); 
   printf("String str2: %s\n", str2);

   return 0;
}

String str1: welcome
String str2: welcome to beginnersbook.com