7-14.txt

《C/C++完美演绎》源代码

/* 范例：7-14 */
#include <stdio.h>
#include <string.h>
int main(void)
{
   /* 设定stpcpy、strcpy、strncpy函数的参数dest */
   char mystpcpy[10];
   char mystrcpy[10];
   char mystrncpy[10];
   char bigmystrncpy[10];
   /* 设定stpcpy、strcpy、strncpy函数的参数src */
   char *str1 = "abcdefghi";
   char *str2= "tiger is good";
   /* 用四个指针变量(a、b、c、d)接收stpcpy、strcpy、strncpy函数的返回值 */
   char *a,*b,*c,*d;
   a = stpcpy(mystpcpy, str1);
   b = strcpy(mystrcpy, str1);
   c = strncpy(mystrncpy, str1,3);  /* 稍后再将'\0'加到所复制的字符串结尾 */
   d = strncpy(bigmystrncpy, str2,13);
   mystrncpy[3]='\0';  /* 加上'\0'，以保持字符串的完整性 */
   /* 输出mystpcpy[10]、mystrcpy[10]、mystrncpy[10] */
   printf("这是用stpcpy复制%s\n", mystpcpy);
   printf("这是用strcpy复制%s\n", mystrcpy);
   printf("这是用strncpy复制%s\n", mystrncpy);
   a=a-5;  /* 指针变量a指向mystpcpy的结尾('\0')，将其往前推5个字符 */
   /* 输出四个指针变量(a、b、c、d) */
   printf("\na=%s,\t&a=%u\t&mystpcpy=%u",a,(void*) a,mystpcpy);
   printf("\nb=%s,\t&b=%u\t&mystrcpy=%u",b,(void*) b,mystrcpy);
   printf("\nc=%s,\t\t&c=%u\t&mystrncpy=%u",c,(void*) c,mystrncpy);
   printf("\nd=%s,\t&d=%u\t&bigmystrncpy=%u",d,(void*) d,bigmystrncpy);
   getchar();
   return 0;
}

程序执行结果：
这是用stpcpy复制abcdefghi
这是用strcpy复制abcdefghi
这是用strncpy复制dbc
a=efghi,   	&a=6618620 	&mystpcpy=6618616
b=abcdefghi,	&b=6618604	&mystrcpy=6618604
c=dbc,  	&c=6618592	&mystrncpy=6618592
d=tiger is goodbc,	&d=6618580	&bigmystrncpy=6618580