Why is std::getline() skipped?

Question

I have this C++ simple program;

#include <iostream>
using std::endl;
using std::cout;
using std::cin;
using std::getline;

#include <string>
using std::string;


struct Repository
{
    string name;
    string path;
    string type;
    string command;
};


int main()
{
    Repository rp;

    cout << "\nEnter repo name: ";
    cin >> rp.name;

    cout << "Enter repo path: ";
    cin >> rp.path;

    cout << "Enter repo type: ";
    cin >> rp.type;

    cout << "Enter repo command: ";
    getline(cin, rp.command);

    cout << "\nRepository information: " << endl;
    cout << rp.name << "\n" << rp.path << "\n" << rp.type << "\n" << rp.command << endl;

    return 0;
}

When execution reaches getline(cin, rp.command) the program just print "Enter repo command: " and skips the getline(cin, rp.command) line so that the user is not given time to respond. What could be the possible problem?

Need more detail. Crash how? What's the type of `.command` ? — MSalters, Aug 01 '14 at 07:02
This still doesn't make a minimal, complete example. Show a small but complete test case from include to main and everything else needed to compile it. — Flexo, Aug 01 '14 at 07:26
The code above shouldn't crash, your problem is probably elsewhere, post a minimal compilable example that shows the crash. — user657267, Aug 01 '14 at 07:27
@Amani [see here](http://stackoverflow.com/help/mcve) for guidelines on posting code — M.M, Aug 01 '14 at 07:33
@Amani the code does not crash for me either, just leaves the `rp.command` empty. — Ferenc Deak, Aug 01 '14 at 07:44
Your heap is probably corrupt before you even enter addToDatabase. Are you mixing versions of Visual Studio or using a Release dll in a debug application. Remember it is generally not safe to use a dll compiled with a different version of Visual Studio in your application. This creates more than 1 independent heap. — drescherjm, Aug 01 '14 at 08:12
@drescherjm, addToDatabase is my own implementation, and though on Windows 7 but I'm using MinGW. — Amani, Aug 01 '14 at 08:40
I think you should use `#include ` and clear buffers in the beginning — MarmiK, Aug 01 '14 at 10:07

score 10 · Accepted Answer · edited May 23 '17 at 11:49

10

Duplicate question answered here.

basically, cin>> doesn't remove new lines from the buffer when the user presses enter. getline() mistakes this for user input along with enter.

You can use cin.ignore() to get rid of those extra characters before using getline().

edited May 23 '17 at 11:49

Community

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answered Aug 01 '14 at 09:40

Johan Hjalmarsson

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score 0 · Answer 2 · edited May 23 '17 at 11:49

0

There are newline characters in cin's buffer, so getline() takes it as an input from user.

You should flush cin buffer before using getline().

edited May 23 '17 at 11:49

Community

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answered Aug 01 '14 at 09:50

Wacek

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Why is std::getline() skipped?

2 Answers2