Thread: Big problems with the Text function

Hammer, the mistake was only made here, when I posted the code and not in my program.

Now I discovered that when I try to open the file in the ReadLanguage () function with the STPFILE constant, I get the error that the file could not be opened. That's strange. Beacuse when I write it like this "fopen ("setup.cfg", "rb")" everything is OK. What could be wrong??

When you spot that you cannot open the file, use this code to find out why (or a similar version of):

Code:

if ((fp = fopen(STPFILE, "rb")) == NULL)
{
       perror(STPFILE);  /* This will print a sensible error message. */
       return (1);
}
/* good open, so continue */

The bug is 100% in this function:

Code:

char *ReadLanguage () // function reads a language file from the file "setup.cfg"
{
    FILE *fin = NULL;
    Setup file;

    if ((fin = fopen (STPFILE, "rb")) != NULL)
    {
        fread (&file, sizeof (Setup), 1, fin);
	fclose (fin);	
	return file.LanguageFile;
    }
    else return NULL;
}

The file STPFILE is opened but I get no return. It's like that the "file.LanguageFile" is empty, but when I open the "setup.cfg" I see that is not empty and contains the right path and filename. Anyone knows what could be wrong in this function?

I already wrote that I get the empty string. And I'm sure that the fread sentence is wrong, but I don't know how to fix it.

The file STPFILE is opened but I get no return. It's like that the "file.LanguageFile" is empty, but when I open the "setup.cfg" I see that is not empty and contains the right path and filename. Anyone knows what could be wrong in this function?

- How do you know the file is opened correctly?
- Put the perror() line in the bottom end of the function to ensure that it tells you if it fails to do the open.
- Put printf() in, like suggested before, except, don't do this:
>printf ("The read language file is %d\n", file.LanguageFile);
because if will fail. You'll need something like this
>printf ("The read language file is %s\n", file.LanguageFile);

And last, change your fread() call to something like this

Code:

if (fread (&file, sizeof (Setup), 1, fin) != 1)
{
     printf("Failed to read 1 record from the config file\n");
     fclose(fin);
     return (NULL);
}

This will ensure that you actually read enough data from the config file to file the struct. I presume that your config file has enough bytes in it?? If not, fread() won't read anything in.

How do you know the file is opened correctly?
- Put the perror() line in the bottom end of the function to ensure that it tells you if it fails to do the open.

Beacuse I put the perror in the if sentence and then it tells me that there is no error.

Put printf() in, like suggested before, except, don't do this:
>printf ("The read language file is %d\n", file.LanguageFile);
because if will fail. You'll need something like this
>printf ("The read language file is %s\n", file.LanguageFile);

In the if sentence I get the result. But when I was calling the function the result was an empty string. And of course, I used the second sentence to do that.

And finally I found the bug. The bug was the "return file.LanguageFile" sentence. Here's the code that fixes the bug .

Code:

char *ReadLanguage () // function reads a language file from the file "setup.cfg"
{
    FILE *fin = NULL;
    Setup file;
    char *Text = NULL, *Temp = NULL;

    if ((fin = fopen (STPFILE, "rb")) != NULL)
    {
        fread (&file, sizeof (Setup), 1, fin);
	fclose (fin);	
        Text = malloc (sizeof (char) * 30);
        if (Text == NULL) exit (1); // this is just temporary
        Temp = Text;
        strncpy (Temp, file.LanguageFile, strlen (file.LanguageFile) + 1);
	return Text;
    }
    else return NULL;
}

I thought that I'll get that warning that I must not return the temporary variable.

Ok. Thanks guys for helping me.