macOS Xcode 4, C++, Importing files?

[kristianmoss]

Hey

I'm having trouble importing files into my C++ code:

#include <iostream>
#include <fstream>
#include <assert.h>  
#include <math.h>
#include "Matrix.h"

using namespace std;

int main() { 
    // Open File
    string line;
    
    ifstream myfile;
    
    myfile.open("SizeImage.txt");
    
    
    if (myfile.good())
    {
        while ( ! myfile.eof())
            {
                myfile >> line;
                cout << line << endl;
            }
        myfile.close();
    }
    
    else cout << "Unable to open file"<< endl; 

        return 0;
        
}

The trouble is probably that "SizeImage.txt" is not in the right folder(But I thought it was). So my question is where in Xcode 4 do I specify the folder that I want to use for my "input" folder, And if you could tell me where I specify the output folder as well that would be great.

 

[chown33]

The trouble is probably that "SizeImage.txt" is not in the right folder(But I thought it was).

No, the real trouble is that the folder where your SizeImage.txt file resides isn't the current working directory when your program runs.

Make sure you understand the concepts of working directory and relative pathname (which your code is using).
http://en.wikipedia.org/wiki/Working_directory
http://en.wikipedia.org/wiki/Path_(computing)


There's no such thing as an "input folder" or "output folder" unless you write code that implements those ideas.

To set the working directory in Xcode 4, try searching Xcode's builtin documentation for keywords working directory.

You will need to edit the Scheme and set the Working Directory to the folder where your file resides. See this Xcode 4 reference doc, under the subheading "Run Your Application to Debug It":
http://developer.apple.com/library/...eptual/Xcode4UserGuide/Building/Building.html
See Figure 5-3.


You might also use the C function getcwd() to confirm at runtime that the working directory is what you expect.

For an example, see my replies here:
https://forums.macrumors.com/threads/1162921/


EDIT (2013-02-12)

The links originally given are broken (now in strikeout). Try this link:
http://developer.apple.com/library/mac/#recipes/xcode_help-scheme_editor/Articles/SchemeProfile.html

If When that breaks, try google search terms:
xcode set working directory site:developer.apple.com
This will search for the given words, confined to the site developer.apple.com.

 

[TastyCocoa]

myfile.open("filepathhere/SizeImage.txt");

Will also work

Also make sure you set xcode to compile in release, not debug mode. The GCC iostream debug libraries don't work very well (or at all sometimes).

 

[lee1210]

Have you tried <cmath>? In C isnan is a macro, in C++ it's an overloaded function. Try cmath and see how it goes.

-Lee