如何判斷IP地址是否合法
阿新 • • 發佈：2019-02-02
如何判斷一個IP地址是否合法，以及如何判斷一個IP地址是否在給定的IP地址範圍內，廢話不多說，上程式碼
其中GetIpInt(string strIp)是將IP地址轉化為可比較大小的整形數，如下：
判斷IP地址是否合法：
bool isValidIP(char *ip) { if (ip == NULL) return false; char temp[4]; int count = 0; while (true) { int index = 0; while (*ip != '\0' && *ip != '.' && count < 4) { temp[index++] = *ip; ip++; } if (index == 4) return false; temp[index] = '\0'; int num = atoi(temp); if (!(num >= 0 && num <= 255)) return false; count++; if (*ip == '\0') { if (count == 4) return true; else return false; } else ip++; } }
判斷一個IP地址是否在給定的IP地址範圍內：
bool IsIpInner(string strDesIp, string strBegin, string strEnd) { char* tempDesIp = const_cast<char*>(strDesIp.c_str()); char* tempBegin = const_cast<char*>(strBegin.c_str()); char* tempEnd = const_cast<char*>(strEnd.c_str()); if (isValidIP(tempDesIp) && isValidIP(tempBegin) && isValidIP(tempEnd)) { unsigned long lDesIp = GetIpInt(strDesIp); unsigned long lBegin = GetIpInt(strBegin);; unsigned long lEnd = GetIpInt(strEnd);; return (((lDesIp >= lBegin) && (lDesIp <= lEnd)) || ((lDesIp <= lBegin) && (lDesIp >= lEnd))); } else return false; }
其中GetIpInt(string strIp)是將IP地址轉化為可比較大小的整形數，如下：
unsigned long GetIpInt(string strIp) { char* tempIp = const_cast<char*>(strIp.c_str()); char *next_token = NULL; char* ch1 = strtok_s(tempIp, ".", &next_token); char* ch2 = strtok_s(NULL, ".", &next_token); char* ch3 = strtok_s(NULL, ".", &next_token); char* ch4 = strtok_s(NULL, ".", &next_token); unsigned long a = stoi(ch1); unsigned long b = stoi(ch2); unsigned long c = stoi(ch3); unsigned long d = stoi(ch4); return a * 255 * 255 * 255 + b * 255 * 255 + c * 255 + d; }