C语言—判断IP地址是否合法

判断输入的IP地址是否合法

#include <stdio.h>unsigned long ip;int judge(int ,int ,int ,int);void main(){char *ipstr[50];int a,b,c,d;printf("please input a ip\n");scanf("%s",ipstr);sscanf(ipstr,"%d.%d.%d.%d",&a,&b,&c,&d);if(judge(a,b,c,d)){ip=inet_addr(ipstr);printf("the int ip is %ld\n",ip);}elseprintf("is not ip\n");}int judge(int a,int b, int c, int d){if (a < 0)return 0;if (a > 255)return 0;if (b < 0)return 0;if (b > 255)return 0;if (c < 0)return 0;if (c > 255)return 0;if (d < 0)return 0;if (d > 255)return 0;return 1;}

运行结果：

please input a ip

12.13.14.15

the int ip is 252579084