c++ string 解析ip

比如输入是192.168.80.12-15，解析成192.168.80.12、192.168.80.13、192.168.80.14、192.168.80.15。

#include <iostream>
#include <vector>
#include <string>
#include <sstream>
#include <fstream>

void ReadDataFromFile(std::string &filename, std::vector<std::string> &lines_feat) {
    std::ifstream vm_info(filename.c_str());
    std::string lines;

    lines_feat.clear();

    while(!vm_info.eof()) {
        getline(vm_info, lines);
            if(lines.empty())
                break;

            lines_feat.push_back(lines);
    }
}

std::vector<std::string> split(const std::string& s, char delimiter) {
    std::vector<std::string> tokens;
    std::string token;
    std::istringstream tokenStream(s);

    while(std::getline(tokenStream, token, delimiter)) {
        tokens.push_back(token);
    }
    return tokens;
}

int stringtoint(const std::string& s) {
    std::istringstream iss(s);

    int num;

    return iss>>num?num:0;
}

void printip(const std::string& s) {
    std::vector<std::string> temp, ip_segment;

    temp=split(s, '-');
    ip_segment=split(temp.front(), '.');

    std::string ip_start=ip_segment.back(), ip_end=temp.back();
    int start, end;
    start=stringtoint(ip_start);
    end=stringtoint(ip_end);

    for(size_t i=start;i<=end;++i) {
        std::cout<<ip_segment[0]<<"."<<ip_segment[1]<<"."<<ip_segment[2]<<"."<<i<<"\n";
    }

}

int main() {
    std::string file_path("vm.data");
    std::vector<std::string> ip_vec;

    ReadDataFromFile(file_path, ip_vec);
    for(std::vector<std::string>::const_iterator it=ip_vec.begin();it!=ip_vec.end();++it) {
        printip(*it);
    }

    return 0;
}