C語言解析ipv4

// parseiP.cpp : 定義控制檯應用程序的入口點。
//

include “stdafx.h”

include

include

include

pragma warning(disable:4996)

using namespace std;

define isip(a) ((a)>=0&&(a)<=255)

//返回n的二進制
void f(int n)
{
if (n)
f(n / 2);
else
return;
printf(“%d”, n % 2);
}

int main()
{
char *aa = “011”;

char dd = 5 + '0';
int cd = atoi(aa); 
printf("%c\n", dd);
system("pause");
int n = 5;
f(n);
map<int, char*>aa1;

pair<int, char*> cc = make_pair(2, const_cast<char*>("cc"));
aa1.insert(cc);
char *ip = "192.168.0.33";
int a=0, b=0, c=0, d=0;
char bip[32] = { 0 };
if (sscanf(ip, "%d.%d.%d.%d", &a, &b, &c, &d) == 4)
{
    if (isip(a) && isip(b) && isip(c) && isip(d))
    {
        printf("%d\n", a);
        itoa(a, bip, 2);
        f(a);
        printf("%s\n", bip);
        printf("%d\n", b);
        printf("%d\n", c);
        printf("%d\n", d);
        printf("%u", a << 24 | b << 16 | c << 8 | d);
        goto end;
    }
    else
        goto error;

}
else
    goto error;

error:
printf(“format error.”);
return -1;

end:
system(“pause”);
return 0;
}