I'm new at C++ and I'm doing a shell, I did an echo command but the text get cut if it has 2 or more args

Asked Jun 23 '22 at 14:17

Active Jun 23 '22 at 14:17

Viewed 48 times

So I'm doing a shell in c++, I'm a noobie here. My code is the following:

#include <iostream>

using namespace std;

int main()
{
    string action;
    bool run = true;
    while (run == true) {
        cout << "shell > ";
        cin >> action;
        if (action == "help" || action == "Help") {
            cout << "Here is a list of commands: \n";
            cout << "help - displays a list of useful commands.\n";

        }else if (action == "echo" || action == "Echo") {
            string echo_c;
            cout << "What to display? ";
            cin >> echo_c;
            cout << echo_c << "\n";
        }
        
    }
}

It prompts me the action and I say "echo", it asks me what to display and I say "Hello world".

Output:

shell > echo
What to display? Hello World
Hello
shell > shell >

It repeats "shell > " and cuts the "world" from "Hello world".

Someone help me plese.

asked Jun 23 '22 at 14:17

A shell is a line based interpreter. You should read lines, not do formatted input. – Captain Giraffe Jun 23 '22 at 14:19
Wdym? Use readline instead of cin? – Jun 23 '22 at 14:20
Oh ok, I oretty new here so that's why I reached for help, thanks guys, – Jun 23 '22 at 14:20
1

`cin >>` to a `std::string` reads only till the first whitespace. – mch Jun 23 '22 at 14:22
Also watch some tutorials on how to use a debugger in your environment. – Captain Giraffe Jun 23 '22 at 14:22
How do I use readline or getline btw? – Jun 23 '22 at 14:25
3

Does this answer your question? [std::cin input with spaces?](https://stackoverflow.com/questions/5838711/stdcin-input-with-spaces) – CharonX Jun 23 '22 at 14:30
`std::string line; if (std::getline(std::cin, line)) {/*do something*/}` – Eljay Jun 23 '22 at 14:31
I cant use getline, it just doesnt appear and generates an error in vs code, is there any other way? – Jun 23 '22 at 14:33
Any other methods? – Jun 23 '22 at 14:42
You forgot to `#include `, [`std::getline`](https://en.cppreference.com/w/cpp/string/basic_string/getline) should work then. – Yksisarvinen Jun 23 '22 at 14:45
It says getline isn't defined. – Jun 23 '22 at 14:45
@Yksisarvinen please help – Jun 23 '22 at 14:47
I MADE IT I JUST NEEDED TO ADD cin.ignore() – Jun 23 '22 at 15:26

I'm new at C++ and I'm doing a shell, I did an echo command but the text get cut if it has 2 or more args

0 Answers0