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I've been searching online to solve the above issue with no success so far. I will describe the issue in more details below.

My program contains only one .cpp file. The program should display text from "test.txt" if this file is opened. Otherwise, it should display the "Failed to open ..." message. The issue follows:

I open terminal, go to the directory containing my file, compile and run with the usual commands: "g++ main.cpp" and "./a.out". When I run my program in this way, using terminal directly, the program works correctly. It displays text when the text file exists and outputs error when it doesn't exist. When I double click the unix executable "a.out", even though the text file exists and is put side by side with the executable, the program displays "Failed to open ..." message. I don't know what to think at that point. Should code contain anything else besides what is below?

Operating system: OS X 10.9.5

#include <iostream>
#include <fstream>
using namespace std;

const int MAX_CHAR_READ = 100;


int main(int argc, const char * argv[])
{
    ifstream read_file;
    cout << endl << endl;

    //Allocate dynamic memory
    char * file = new char[strlen("test.txt") + 1];
    char * text_line = new char[MAX_CHAR_READ + 1];

    strcpy(file, "test.txt");

    //Attempt to open a file for reading
    read_file.open(file);

    if(read_file.is_open() == true)
    {
        cout << "File: " << file << " is open!" << endl;
        read_file.get(text_line, MAX_CHAR_READ, ';');
        cout << text_line << endl;
        read_file.close();
    }
    else
        cout << "Failed to open: " << file << endl;

    cout << endl << endl;

    //Deallocate dynamic memory
    delete [] file;
    delete [] text_line;
    return 0;
}

Program execution example using terminal manually:

$ cd Desktop/Other/Test
$ g++ main.cpp
$ ./a.out

File: test.txt is open!
Hello World!

$

Program execution example double clicking the same executable:

$/Users/vladimirmeshcheryakov/Desktop/Other/Test/a.out ; exit;

Failed to open: test.txt

logout

[Process completed]
Vladimir Meshcheryakov
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  • The program's running directory is probably not Test and therefore can't find the file test.txt. – Anon Mail Dec 09 '16 at 21:14
  • The executable is run from the same directory just in different ways: directly using terminal or double clicking. Do I misunderstand "running directory"? – Vladimir Meshcheryakov Dec 09 '16 at 21:28
  • It's not clear what the running directory is when you double click. You can check by printing out the running directory and also trying to access the file using it's full path. – Anon Mail Dec 10 '16 at 14:30
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    Ok, it seems to be the working directory issue as you've mentioned. When I write additional code in the program above to display the current working directory, the output differs when the program is double clicked from when it is run through terminal. If I place my test.txt file at the location pointed to by the double clicked program (with additional code that prints working directory path), the above program opens test.txt file and works as it should. Now I need to find a solution of obtaining the path to executable. Thank you! – Vladimir Meshcheryakov Dec 15 '16 at 00:45

2 Answers2

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one of the possible things to cause it could be the case of running the terminal as superuser, in a folder with access restriction to the regular user. (superuser doesn't have that restriction)

solution: give current user the right to Read/Write in this folder.

Arty McLabin
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Now I need to find a solution of obtaining the path to executable.

Check whether argv[0] contains it.

Armali
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