Doubt: File I/O and DLLs

Hello everybody!

I'm a newbie on programming and I'm trying to create a routine to write some calculated variables on a text file. There is a lot of file I/O examples on the internet, and I've made some by myself (they work fine), but when I try to use them on a DLL, nothing happens, though the compilation runs successfully.

Is there any mystery about File I/O and DLLs on C?

Thanks in advance,

Gabriel Casagrande

I don't get this question.
Post code...
...and, C or C++?

I'm using this language to edit an open-source software, which has a graphical interface that uses an engine (a DLL made in C). This software is for hydraulic systems project. On my final thesis, I have to change the original water demand calculations of this model.

So, I am trying to create a routine to write the variables on a text file and then, pass by pass, know if what I am calculating is correct or not.

When I use the codes I created in a different project (a console application), everything runs fine: the text file is created, and the variables are written on the file. But, using the same code on the DLL, nothing happens.

The code is:

Code:

---


void demands()

{
    FILE *f;
    int i;
    f = fopen("demands.txt", "w");
    for (i=1; i<=Njuncs; i++)
  {
      fprintf(f, "%d %d/n", i, D[i]);
  }
  fclose(f);

}

---

Where D[i] is the demands array, calculated in other function. I've tried to run the code inside that function, but nothing happened either.

Thanks,

Gabriel

Are D and Njuncs global variables? Are you sure Njuncs has the value you think it has? It looks like you're using C and not C++, so this topic should be moved to appropriate section of the forum. Or, are you using C++?

Also, newline char is '\n' and not "/n". ;)

What does 'nothing happens' mean? Ensure your function is called properly. And check if the file is even created.

Quote:

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Originally Posted by Xupicor

Are D and Njuncs global variables? Are you sure Njuncs has the value you think it has? It looks like you're using C and not C++, so this topic should be moved to appropriate section of the forum. Or, are you using C++?

Also, newline char is '\n' and not "/n". ;)

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Ops! Sorry, It's true, the topic is in the wrong section... I'm using C
How could I move it to the right section?

D[i] and Njuncs are global and I've tried to use this code inside the D[i] calculation routine. I guess everything's alright with Njuncs, but I'll look at this carefully. :)

Quote:

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Originally Posted by kmdv

What does 'nothing happens' mean? Ensure your function is called properly. And check if the file is even created.

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I mean that the file is not created =)

Quote:

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Originally Posted by gabrielksa

Ops! Sorry, It's true, the topic is in the wrong section... I'm using C
How could I move it to the right section?

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Moved to C programming forum.