Is there an option besides system("pause") for keeping an executable open?

Question

I am trying to run the Caesar program from understanding C++ & it won't stay open once debugged. What to do?

I have used system("pause") to no avail. I have also tried getchar(), which has worked in other applications but does not work for this executable.

#include <iostream>
#include <fstream>
#include <string>
#include <sstream>

using namespace std;

/** 
Encrypts a stream using the Caesar cipher
@param in- the stream to read from
@param out- the stream to write to 
@param k- the encryption key
*/

void encrypt_file(ifstream& in, ofstream& out, int k)
{
    char ch;
    while (in.get(ch))
    {
        out.put(ch + k);
    }
}

int main(int argc, char* argv[])
{
    int key = 3;
    int file_count = 0; // The number of files specified
    ifstream in_file;
    ofstream out_file;

    for (int i = 1; i < argc; i++) //Process all command-line arguments
    {
        string arg = argv[i]; // The currently processed argument

        if (arg == "-d") // The decryption option
        {
            key = -3;
        }
        else // It is a file name
        {
            file_count++;

            if (file_count == 1) // The first file name
            {
                in_file.open(arg.c_str());
                if (in_file.fail()) // Exit the program if opening failed
                {
                    cout << "Error opening input file " << arg << endl;
                    return 1;
                }
            }
        }
    }

    if (file_count != 2) // Exit if the user didn't specify two files
    {
        cout << "Usage: " << argv[0] << " [-d] infile outfile" << endl;
        return 1;
    }

    encrypt_file(in_file, out_file, key);

    getchar();
    //system("pause");

    return 0;
}

Expected result is the application staying open while deciphering the code.

The program will run until main is finished. The fact that it is returning means execution is finished(baring any faults). It also doesn't look like you're defining out_file anywhere? — BTables, Sep 17 '19 at 01:07
`out_file` is *declared* at the top of `main()`, below `in_file`, but `out_file` is never actually *opened* before `encrypt_file()` is called. — Remy Lebeau, Sep 17 '19 at 01:08
@RemyLebeau It's declared, not defined...Where is it supposed to be writing to? — BTables, Sep 17 '19 at 01:11
This may be an XY problem. It sounds like maybe what you really want is for the *console* to stay open after the application terminates. That would be something to configure in your OS / windowing system / development environment, not something that would be part of your program. — Nate Eldredge, Sep 17 '19 at 01:27
Possible duplicate of [Preventing console window from closing on Visual Studio C/C++ Console application](https://stackoverflow.com/questions/1775865/preventing-console-window-from-closing-on-visual-studio-c-c-console-applicatio) — Nate Eldredge, Sep 17 '19 at 01:29
Possible duplicate of [Alternative to system("PAUSE")?](https://stackoverflow.com/questions/36797905/alternative-to-systempause) — , Sep 17 '19 at 02:41
I suggest you could try to explicitly set the Subsystem to Console under Configuration Properties / Linker / System. — Jeaninez - MSFT, Sep 17 '19 at 06:10
Try: `Debug / Start Without Debugging` or just debug and set a breakpoint at the closing brace of `main`. — harper, Sep 17 '19 at 10:44

score 0 · Answer 1 · answered Sep 17 '19 at 01:21

0

You're not actually pointing the ofstream to anywhere. As far as I can tell an ofstream will buffer input until you give it somewhere to point to(disclaimer, I could be wrong).

Regardless, since you're not opening anything for out_file, it will not write to whatever file you're wanting it to. Thus, it will look like your program isn't doing what you want and simply returning.

answered Sep 17 '19 at 01:21

BTables

4,413
2
11
30

"*As far as I can tell an ofstream will buffer input until you give it somewhere to point to(disclaimer, I could be wrong)*" - if the `ofstream` is not opened, it simply won't write anywhere, and its `badbit` state will be set. – Remy Lebeau Sep 17 '19 at 01:24

score 0 · Answer 2 · answered Sep 17 '19 at 06:13

0

You can try using system("pause/nul"); which i use when making prograns in VS because they wont stay open but i put them only before the return 0; so they close after i press a button but i think it works everywhere, give it a try.

answered Sep 17 '19 at 06:13

xX randomryze Xx

155
11

Is there an option besides system("pause") for keeping an executable open?

2 Answers2