#include<string.h>

#include<stdlib.h>

#include<stdio.h>

#include<string>

int _System(const std::string cmd, std::string &output)

{

    FILE * fp;

    int res = -;

    if ((fp = popen(cmd.c_str(), "r") ) == NULL)

    {

        printf("Popen Error!\n");

        return -;

    }

    else

    {

        char pRetMsg[]={};

        //get lastest result

        while(fgets(pRetMsg,, fp) != NULL)

        {

            output+=pRetMsg;

        }

        if ( (res = pclose(fp)) == -)

        {

            printf("close popenerror!\n");

            return -;

        }

        return ;

    }

}

int main()

{

    //test cmd

    //char *cmd = "lsmod";

    std::string cmd = "curl -s members.3322.org/dyndns/getip";

    int ret = ;

    std::string result;

    ret  = _System(cmd, result);

    printf("ret = %d \nresult = %s\nlength = %d \n", ret, result.c_str(),result.length());

    return ;

}

[login@server ~]$ g++ callsystemrt.cpp && ./a.out

ret =

result = 120.132.101.54

length =