第一次读取后程序执行不会在 scanf() 处停止

Question

I want that at every iteration of the do-while() loop the program stops at the scanf() function, but the program loops the same amount of times as the number of white spaces that the read string contains before stoping again at the scanf()

enum Comando
{
    AYUDA,
    LOGIN,
    LOGOUT,
    LISTAR_BUSES,
    LISTAR_RUTAS,
    LISTAR_VIAJES, 
    NULL_COMMAND 
};

//Funcion que registra el comando ingresado por el usuario para indicarle al programa que es lo que debe hacer
pair<Comando, queue<char*>> ProcesarComando(char comandoEntero[20]);
void MostrarAyuda();

int main()
{
    bool salir = false;
    char comando[20];
    Comando cmd;

    do
    {
        printf("\n\t$ ");
        scanf(" %s", comando);

        cmd = ProcesarComando(comando).first;

        switch(cmd)
        {
            case AYUDA:

            break;
            case LOGIN:

            break;
            case LOGOUT:

            break;
            case LISTAR_BUSES:

            break;
            case LISTAR_RUTAS:

            break;
            case LISTAR_VIAJES:

            break; 
            case NULL_COMMAND:

            break;           
        }
    }
    while(!salir);

    //system("pause");
    return 0;
}

pair<Comando, queue<char*>> ProcesarComando(char comandoEntero[20])
{
    int pos = 0;
    char *argumento, *comandoNombre;
    bool tieneParametros = false;
    pair<Comando, queue<char*>> retorno;

    argumento = new char[20];
    
    while(comandoEntero[pos] != '\0')
    {
        if(comandoEntero[pos] == '<'|| comandoEntero[pos] == '[')
        {
            tieneParametros = true;
        }
        else if(tieneParametros && comandoEntero[pos] != ' ' && comandoEntero[pos] != '<' && comandoEntero[pos] != '>' && comandoEntero[pos] != '[' && comandoEntero[pos] != ']')
        {
            strncat(argumento, &comandoEntero[pos], 1);
        }
        else if(tieneParametros && comandoEntero[pos] == ' ')
        {   
            cout<<"HOLAAAAAAA";
            retorno.second.push(argumento);
            memset(argumento, '\0', strlen(argumento));
            tieneParametros = false;
        }
        pos++;
    }

    comandoNombre = new char[20];
    comandoNombre = strtok(comandoEntero, " ");

    if(strcmp(comandoNombre, "ayuda") == 0)
    {
        retorno.first = AYUDA;
        return retorno;
    }
    else if(strcmp(comandoNombre, "login") == 0)
    {
        retorno.first = LOGIN;
        return retorno;
    }
    else if(strcmp(comandoNombre, "logout") == 0)
    {
        retorno.first = LOGOUT;
        return retorno;
    }
    else if(strcmp(comandoNombre, "listar_buses") == 0)
    {
        retorno.first = LISTAR_BUSES;
        return retorno;
    }
    else if(strcmp(comandoNombre, "listar_rutas") == 0)
    {
        retorno.first = LISTAR_RUTAS;
        return retorno;
    }
    else if(strcmp(comandoNombre, "listar_viajes") == 0)
    {
        retorno.first = LISTAR_VIAJES;
        return retorno;
    }

    // printf("\n%s", retorno.second.front());
    // retorno.second.pop();
    // printf("\n%s", retorno.second.front());

    retorno.first = NULL_COMMAND;
    return retorno;
}

So, because the program is not stoping at the scanf(), it is printing all those money signs but without letting me interact with the program until the amount of the string white spaces are reached...

I know that it may be something dumb, but couldn't figure it out, hope that you guys could help me.THANKS:v

Answer 1

Here I am posting a proper C++ implementation of your code. I know that code-only answers are not recommended. But here, I don't have much to tell you. You need to yourself check about the things you lack knowledge about. Better search things on this site .

#include <algorithm>
#include <iostream>
#include <queue>
#include <sstream>
#include <string>
#include <utility>
#include <vector>

enum Comando {
    AYUDA,
    LOGIN,
    LOGOUT,
    LISTAR_BUSES,
    LISTAR_RUTAS,
    LISTAR_VIAJES,
    NULL_COMMAND
};

auto ProcesarComando(std::string comandoEntero) {

    std::string argumento, comandoNombre;
    bool tieneParametros = false;
    std::queue<std::string> retorno;

    for (auto &&i : comandoEntero)
        if (i == '<' or i == '[')
            tieneParametros = true;
        else if (tieneParametros and std::string(" []<>").find(i) == size_t(-1))
            argumento.push_back(i);

        else if (tieneParametros and i == ' ') {
            std::cout << "HOLAAAAAAA\n";
            retorno.push(argumento);
            argumento.clear();
            tieneParametros = false;
        }

    std::stringstream(comandoEntero) >> comandoNombre;
    const std::vector<std::string> cmd = {"ayuda",        "login",
                                          "logout",       "listar_buses",
                                          "listar_rutas", "listar_viajes"};

    return std::make_pair(
        static_cast<Comando>(std::find(cmd.begin(), cmd.end(), comandoNombre) -
                             cmd.begin()),
        retorno);
}

int main() {
    do {
        std::cout << "\n$ ";
        std::string comando;
        std::getline(std::cin, comando);

        switch (ProcesarComando(comando).first) {
        case AYUDA:

            break;
        case LOGIN:

            break;
        case LOGOUT:

            break;
        case LISTAR_BUSES:

            break;
        case LISTAR_RUTAS:

            break;
        case LISTAR_VIAJES:

            break;
        default: // case NULL_COMMAND:

        }
    } while (true);
}