9.12 C语言知识大复习 gbk2utf8

#include <stdio.h>
const char *getstr()
{
        const char *s = "hello world";      //返回一个常量字符串地址是有效的
        return s;
}
int main()
{
        printf("%s\n",getstr());
        return 0;
}

#include <stdio.h>
const char *getstr()
{
        char s[100] = "hello world";       //返回一个栈上的地址是无意义的，因为函数结束即释放
        return s;
}
int main()
{
        printf("%s\n",getstr());
        return 0;
}

int gbk2utf8(char *src, size_t *srclen, char *dest, size_t *destlen)
{
	iconv_t cd = iconv_open("UTF8", "GBK"); //源字符串为GBK,目标UTF8
	if (cd == (iconv_t) - 1)
	{
		printf("open iconv error %s\n", strerror(errno));
		return -1;
	}
	size_t rc = iconv(cd, &src, srclen, &dest, destlen); //将src字符串转化为目标dest
	if (rc == (size_t) - 1)
	{
		printf("iconv error %s\n", strerror(errno));
		return -1;
	}
	iconv_close(cd);
	return 0;
}