Thread: iostream problem

This all the contents in common.h
extern int currentLineNumber;
extern int currentNestingLevel;

This all the contents in common.cpp
int currentNestingLevel = 0;
int currentLineNumber = 0;

Now you can see why I did not include it in the post, but I did include it in buffer.cpp! Commenting out this include is an error, I actually do include it!
It's only used in one function.

I did not know you cannot use namespaces in header files!!! But I also did not try to use it in header files for this project!

I also made a little test project using fstream: I opened for reading, read, closed, opened for writing, wrote, closed etc and all compiled OK. I even put in "fstream file;" the line that my other project is complaining about and the compiler took that line also. So it can't be the compiler or the project. Something has got to be screwed up with the code of the includes in buffer.cpp.

> I did not know you cannot use namespaces in header files!
I didn't say you cannot.
I said it's a supremely BAD idea to do so.

> I still have to figure out why std:: namespaces are needed in a header file that uses a library.
Because everything in modern C++ is in one namespace or another.

Here is an example program using namespaces.

Code:

#include <iostream>
#include <fstream>

void foo ( ) {
    std::cout << "This is foo\n";
}

namespace cprog {

int bar ( ) {
    return 42;
}

}

int main ( ) {
    std::fstream is;        // fstream is in the std:: namespace
    foo();                  // foo is in the global namespace
    int x = cprog::bar();   // bar is in the cprog namespace
    std::cout << "Bar=" << x << "\n";
}

And the same with using namespace

Code:

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

void foo ( ) {
    cout << "This is foo\n";
}

namespace cprog {

int bar ( ) {
    return 42;
}

}

int main ( ) {
    fstream is;             // fstream is in the std:: namespace
    foo();                  // foo is in the global namespace
    int x = cprog::bar();   // bar is in the cprog namespace
    cout << "Bar=" << x << "\n";
}

In short, "using namespace std;" is a lazy one line sop to make ancient C++ programs somewhat usable in modern C++ (when everything moved from the global namespace to the std namespace).

While you're writing toy programs that depend only on the standard library, it's somewhat harmless.

But when you get to writing code importing namespaces from several external libraries, then knowing how to use namespaces properly becomes far more important.
So if you want to save some future grief, stop being lazy and learn to write std:: in front of all the references to the standard library.

There is a half-way house approach.

Code:

#include <iostream>
#include <fstream>

// I use std::cout a lot, so just make this one thing a bit
// easier on the eye and the fingers.
// Everything else would need to be qualified with std::
using std::cout;

void foo ( ) {
    cout << "This is foo\n";
}

namespace cprog {

int bar ( ) {
    return 42;
}

}

int main ( ) {
    std::fstream is;        // fstream is in the std:: namespace
    foo();                  // foo is in the global namespace
    int x = cprog::bar();   // bar is in the cprog namespace
    cout << "Bar=" << x << "\n";
}

> After entering in the .h and .cpp files main.cpp is no longer needed so I remove it ...
Make sure to save the project.

Code:

TTextInBuffer::TTextInBuffer(const char *pInputFileName, TAbortCode ac)
    : pFileName(new char[strlen(pInputFileName) + 1])
{
    //--Copy the input file name.
    strcpy(pFileName, pInputFileName);

//--Open the input file.  Abort if failed.
    file.open(pFileName, std::ios::in /* | std::ios::noreplace */ );  // +=+ file is declared in buffer.h per discussion(std::fstream file)
    if (!file.good())           // +=+ file.good() is not working!!!
        AbortTranslation(ac);   // +=+ this is exiting the program!!!
}

When I run this is in the debugger, pFileName comes from argv[1] and the watch shows the intended file from the command line. 'noreplace' has been commented out, but the code skips to the AbortTranslation line and exits! If I take out the last 2 lines, the code runs, but all I get are empty entries from the not opened file! So the only thing left is the file.open line and the only thing that I changed there was to eliminate the 'noreplace'! Why doesn't the file open?

I do have the most recent compiler, version 13.1.0) and that should allow -std=c++23 but I have not figured out how to do this in either CodeBlocks or DevC++!

Your string idea was nice but my code, an enum of strings, didn't seem feasible so I just changed char * to const char * and the compiler was very happy.
maxcy

Try getting more information, rather than saying "it doesn't work".

Code:

    if (!file.good()) {
        std::cerr << "Could not open >" << pFileName << "<\n";
        std::cerr << "Error=" << std::strerror(errno) << "\n";  // #include <cerrno>
        AbortTranslation(ac);   // +=+ this is exiting the program!!!

Note the use of printing >< immediately around the filename, as this helps spot things like stray spaces and/or newlines in whatever you think the filename is.

> When I run this is in the debugger, pFileName comes from argv[1]
Bear in mind that what the program considers to be "the current directory" can differ depending on how you invoke the program.
- running in the debugger
- running from an IDE menu 'run'
- running from an external command line.

The file may exist, but you could be looking in the wrong place.

Find out where it's looking
_getcwd, _wgetcwd | Microsoft Learn
getcwd(3) - Linux manual page

The current directory isn't necessarily where the executable is.

Good, now do the same thing in the error path when it can't find the file.

The current directory isn't a fixed thing set at the start of the program. If some other part of your code does a chdir (that you don't know about, or you forgot about), then you can easily be looking in the wrong place.

Code:

file.open (pFileName, std::fstream::in);
if (file.fail())
{
   // This is the error path (through the code)
   cout << "*pFileName:  ";
   for ( int i =0; i <= 7; i++) {
        cout << pFileName[i];  // name is good
   }
   cout << endl;
   std::cerr << "Could not open >" << pFileName << "<\n"; // so is this
   std::cerr << "Error=" << std::strerror(errno) << "\n";  // #include <cerrno>
   AbortTranslation(ac);
   file.clear();
}

Put the getcwd code here also, to find out in what directory it tried to find the file.