C语言下的ip与long之间的互换(long2ip,ip2long)

#include <stdio.h>
#include <winsock.h>

char *long2ip(u_long in);
u_long ip2long(char *ip);

int main()
{
    char p[16];
    printf("请输入IP地址:\n");
    scanf("%s",p);
    u_long l = ip2long(p);
    printf("%s\n",long2ip(l));
    int inum = 0 ;
    scanf("%d",inum);
    return 0;
}

char *long2ip(u_long in)
{
    u_char *p;
    p = (u_char*)(&in);
    static char output[16];
    _snprintf_s(output,16,16,"%d.%d.%d.%d",p[0],p[1],p[2],p[3]);
    return output;
}

u_long ip2long(char *ip)
{
    u_char addr[16];
    sscanf(ip,"%d.%d.%d.%d",addr,addr+1,addr+2,addr+3);
    u_long *vl = (u_long*)(&addr);
    return *vl;
}