C判断IP地址的合法性

#include

int is_valid_ip(const char *ip) {

int section = 0; //每⼀节的⼗进制值 int dot = 0; //⼏个点分隔符

int last = -1; //每⼀节中上⼀个字符 while(*ip) {

if(*ip == '.') {

dot++; if(dot > 3) {

return 0; }

if(section >= 0 && section <=255) {

section = 0; }else{

return 0; }

}else if(*ip >= '0' && *ip <= '9') {

section = section * 10 + *ip - '0'; if(last == '0') {

return 0; } }else{

return 0; }

last = *ip; ip++; }

if(section >= 0 && section <=255) {

if(3 == dot) {

section = 0;

printf (\"IP address success!\\n\"); //printf (\"%d\\n\ return 0; } }

return 1; }

int main(){

is_valid_ip(\"192.249.23.123\");}