Thread: Opening a text file in C

I have a program that is to open a text file. The code compiles, appears to validate as it should and so on....except:

If I used this code to open the file:

bank = fopen("C:\\tma307\\itembank.txt", "r");

it opens just fine.

but if I use:

bank = fopen(Bank, "r");

it won't open (I get a popup error that reads "Project1 has caused an error in CC3260MT.DLL. Project1 will now close")

Bank is the itemfile and bank is the pointer for my program.

What hapens is:

--I click on run (using Borland C++ Builder)

--It brings me to a menu in dos and prompts me to select an item

--I select v (for validate file) and it brings me to a blank dos screen where I am prompted to type in the disk file name.

--This is where I first noticed the problem. I don't even have to type in a disk file name to get my text file. I could just hit enter or happy new year for that matter.

I believe that as I have already declared the disk file name in the code, the program already knows where to go. But, if I make changes to the text file (and save them of course), it doesn't recognize anything different.

I have read many many articles on fopen etc. to try and figure this one out but have been unsuccessful.

Any suggestions would be greatly appreciated!

Thanks for replying Shadow. Yes it is late and yes it is confusing.

I am opening the text file to validate certain conditions within the text. For example if a line reads more than 64 characters in length, return error reading "file length is too long - edit line length...".

So I believe that the correct way to open this file to validate it is:

FILE * bank;
bank = fopen(Bank, "r");

but it will only let me open the file with:

FILE * bank;
bank = fopen("C:\\tma307\\itembank.txt", "r");

I don't understand why I have to specify the path address there. I thought that I might have done something in main but all is in order there (I have compared my main.c with another classmate and they are exactly the same.

Perplexing isn't it!

Thanks for reply Salem. I agree that better variable names would have been ideal however they are part of my assignment of which I cannot change. I think they do that to keep us on our toes.

Anyway, here is more code:

int validate_file ( const char Bank[], int D_A[], int summary )
{
FILE * bank; // file pointer variable to item-file Bank

int err,
....

clrscr ();
bank = fopen("C:\\tma307\\itembank.txt", "r"); //

if...
{
printf("Error 7: ...");
...

hit_a_key("\n\n\n");

for( i=0; i!= EOF; ++i)
{
...and so on.

Given that function,
bank = fopen(Bank, "r");
seems OK

So the only question is
How are you calling this function?

I'm calling it as follows:

if(validate_file ( Bank, D_A, summary ) )
{
(bank != NULL)
{
printf("Error 7: Unable to open itembank file.\n");
printf("try to use the full name: C:\\TMA307itembank.txt\n");
}
else if (bank==NULL)
{
printf("The itembank file you have requested has opened successfully");
}
hit_a_key("\n\n\n");

for( i=0; i!= EOF; ++i)
{
...

> (bank != NULL)
This bank is not the same as the local variable bank in the validate_file function.

This bank is uninitialised

Sorry Salem, I missed a part of the code when I was pasting it. It should read:

if (bank != NULL)
...

Perhaps if you posted all your code, not just random snippets

Besides, doesn't matter how you wrote it, you still have a scope problem

In validate_file
bank = fopen("C:\\tma307\\itembank.txt", "r"); //

This is NOT the same bank as the one in the caller of validate_file

Yes, I agree that I have a scope problem. That's why I didn't want to post the whole code (it is very long).

My assignment specs state "Bank is the disk-name of an item-file to be validated"

So if I state Bank=fopen I get the following compiler error:

"can't modify a const object"

I know it must be quite difficult to give me advice when all the project facts are not know. Any suggestions on where I might get further info on "scope" issues or what else I might search under? I am sure that I have reviewed most of the sites on fopen etc.

Thanks

Perhaps it should be like this

Code:

if ( validate_file ( Bank, D_A, summary ) ) {
  bank = fopen(Bank, "r"); 
}

Thanks Salem but I tried that and it won't open the file for me. I just get a blank screen (yes I checked to make sure that there was indeed data in the text file).

Any other suggestions? Anyone?

I know there's a genius out there with the answer. Or any suggestions on where to look (ie a tutorial etc)?

> That's why I didn't want to post the whole code (it is very long).

That's why there's a box at the bottom of the reply window called

"Attach file:"

I would suggest you use it.

I'm worried by the apparent size of this program, and the lack of understanding of some basic C programming principles.