Thread: I have tried a lot...but this is not working.

>help????
I'm afraid to compile and run your code, but in such cases I suggest that you ditch what you have and start over, this time taking a more structured approach. In other words:

1) Create the inventory type.
2) Write a function to fill one variable of the inventory type from interactive input.
3) Write a function to write one variable of the inventory type to interactive output.
6) Write a function to update one variable of the inventory type.
4) Write a function to fill one variable of the inventory type from a file stream.
5) Write a function to write one variable of the inventory type to a file stream.

With these functions in hand you can do a surprising amount of useful things. More importantly, you are able to work with the smallest object in your program in its entirety. Just by using these functions in a loop, you have a database.

Your task after that is to work with sequences of inventory objects, such as sorting and searching. Both of these at their most naive are ridiculously easy, so you should have no problem there.

The key is to break the program down into teeny tiny pieces that you can work with and test individually so that when you put them together, they all work as they should. It saves you a lot of trouble when you have a few hundred (experienced programmers read this as hundred-thousand) lines of code and a bug that you can't seem to find.

Originally posted by Prelude

1) Create the inventory type.
2) Write a function to fill one variable of the inventory type from interactive input.
3) Write a function to write one variable of the inventory type to interactive output.
6) Write a function to update one variable of the inventory type.
4) Write a function to fill one variable of the inventory type from a file stream.
5) Write a function to write one variable of the inventory type to a file stream.

hmmm....okay....but can you explaing what you mean by^^^3

>2) Write a function to fill one variable of the inventory type from interactive input.

but then i have chars, ints and floats.....does that mean 3 diff functions.

>but then i have chars, ints and floats.....does that mean 3 diff functions.
All of those are in a single structure variable, so you can simply fill it and use that:

Code:

struct inventory interactive_fill ( void )
{
  struct inventory rv;
  char buff[BUFSIZ];

  printf ( "Name: " );
  fflush ( stdout );
  fgets ( rv.name, sizeof rv.name, stdin );
  printf ( "Price: " );
  fflush ( stdout );
  fgets ( buff, sizeof buff, stdin );
  sscanf ( buff, "%f", &rv.price );
  ...

  return rv;
}

>where was i going wrong...
The only obvious problem is that saveData doesn't close the file that it opened and you don't cose it elsewhere either. A cursory look doesn't show anything else seriously wrong as long as you avoid the undefined behavior that you know about already and assuming the pretty printing works as it should.

Code:

int loadData(structure inventory[],int* arrayL)

I haven't looked at the attached file, so I don't know if the above is an alias or not, but you'd use the struct keyword for structures.

scrap the fflush(stdin) before the others catch it.
use strtol instead of atoi
lose gets(buf), and use fgets instead

I *believe* you can simply the reading/writing to one function by passing in your data files from main, or open a single file for both reading and writing.

Code:

int fileOps(struct *, int *, FILE *, FILE *);

>I have simplified my programme to these 3 functions
Your problems are coming from addItems. And since you've apparently narrowed the problem down to these three functions, it should be easy to locate where things go wrong if you've been paying attention.

>int i=*arrayL;
Because you use feof as a loop condition when reading the file, *arrayL probably has a value one higher than you want, which is also probably why you subtract one from it when you save the data. As such, this should also be

int i = *arrayL - 1;

Or you could fix the code that you "already know" is wrong. When your willful ignorance effects the normal operation of your programs, it's time to take your head out of your ass and learn to do things the right way instead of try to (poorly) work around the issues that could easily be avoided.

>arrayL++;
This does nothing but advance the pointer to the next block of memory, it doesn't increment arrayL the way you think it does. Try this instead:

(*arrayL)++;

Note that while ++ and * have the same precedence, they are associated from right to left, so the ++ is performed first, resulting in moving the pointer to the next memory block and dereferencing that address. Parentheses force the dereference to be performed first, resulting in incrementing the contents of arrayL as you would expect.

>but you'd use the struct keyword for structures.
It is a typedef'd structure, so the code is correct.

>scrap the fflush(stdin) before the others catch it.
>lose gets(buf), and use fgets instead
nomi already asked that we not comment on these in another thread. We can inform the ignorant, but we can't help the stupid if they don't want us to.

Moving on to phase 3....

I decided i will scrap the fflush(stdin)
Replacement = while(getchar () != '\n');???

ALthough i dont know how I can replace the gets(buff)?
>gets(buff1);
Replacement = fgets(buff1,MAXchar,stdin);???

Are my replacements okay? and
Why replace gets with fgets???
Is it bcoz of '\n', coz i have used a much longer way to take them out.....

EDIT: cool....my program works, now to format it and put some pretty stuff in...

>Although i dont know how gets is wrong???....
Look in the Top Secret Files for super secret information.

>Is that a direct insult to me....
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I'm sorry. I'm a little off today, but I have no excuse for insulting you like that.
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