strncpy实现

#include<stdio.h>
char *my_strncpy(char *dest,char *src,int n)
{
     int i;
     for(i=0;i<n && src[i]!='';i++)
          dest[i] = src[i];
     for(;i<n;i++)
          dest[i] = '';
     return dest;
}

char *my_strncpy1(char *dest,const   char   *src,int   n)
{
   int i=0;
   char *ret=dest;
   while(*src != ' ' && i <n)
    {
       *dest++ = *src++;
       i++;
     }
   return  ret;  
}