从cplusplus.com论坛获得它，只需调用GetSystemOutput("/usr/bin/lsb_release -a")即可.

Got it from cplusplus.com forums, a simple call GetSystemOutput("/usr/bin/lsb_release -a") works.

char* GetSystemOutput(char* cmd){
        int buff_size = 32;
    char* buff = new char[buff_size];

        char* ret = NULL;
        string str = "";

    int fd[2];
    int old_fd[3];
    pipe(fd);


        old_fd[0] = dup(STDIN_FILENO);
        old_fd[1] = dup(STDOUT_FILENO);
        old_fd[2] = dup(STDERR_FILENO);

        int pid = fork();
        switch(pid){
                case 0:
                        close(fd[0]);
                        close(STDOUT_FILENO);
                        close(STDERR_FILENO);
                        dup2(fd[1], STDOUT_FILENO);
                        dup2(fd[1], STDERR_FILENO);
                        system(cmd);
                        //execlp((const char*)cmd, cmd,0);
                        close (fd[1]);
                        exit(0);
                        break;
                case -1:
                        cerr << "GetSystemOutput/fork() error\n" << endl;
                        exit(1);
                default:
                        close(fd[1]);
                        dup2(fd[0], STDIN_FILENO);

                        int rc = 1;
                        while (rc > 0){
                                rc = read(fd[0], buff, buff_size);
                                str.append(buff, rc);
                                //memset(buff, 0, buff_size);
                        }

                        ret = new char [strlen((char*)str.c_str())];

                        strcpy(ret, (char*)str.c_str());

                        waitpid(pid, NULL, 0);
                        close(fd[0]);
        }

        dup2(STDIN_FILENO, old_fd[0]);
        dup2(STDOUT_FILENO, old_fd[1]);
        dup2(STDERR_FILENO, old_fd[2]);

    return ret;
}