C C++ tut error

[Keiyentai]

Hey everyone I did a tutorial on a website that seems to combines C and C++ for the program witch is an inventory program.

Here it is. It runs and compiles fine but after I enter the data at the end it crashes on me. I am still new to C\C++ so any help is verry apreciated.

 // Program to perform file processing using the FILE structure
// Author: Jules Larson. Revised by Jeremy Jones 2005
#include <iostream>
using namespace std;
int main()
{
	char Make[20], Model[20];
	unsigned int CarYear;
	long Mileage;
	
	FILE *CarInventory = fopen("cars.inv", "w");
	
	cout << "Enter the following pieces of information\n";
	cout << "Make:	 "; gets(Make);
	cout << "Model:	"; gets(Model);
	cout << "Year:	"; cin >> CarYear;
	cout << "Mileage:  "; cin >> Mileage;
	
	fprintf(CarInventory, "%s\n", Make);
	fprintf(CarInventory, "%s\n", Model);
	fprintf(CarInventory, "%s\n", CarYear);
	fprintf(CarInventory, "%s\n", Mileage);

	FILE *Carinventory = fopen("cars.inv", "r+");
	
		 fscanf(CarInventory, "%s\n", Make);
		 fscanf(CarInventory, "%s\n", Model);
		 fscanf(CarInventory, "%d\n", &CarYear);
		 fscanf(CarInventory, "%d\n", &Mileage);
		 
		 cout << "Information about the car";
		 cout << "\nMake:   " << Make;
		 cout << "\nModel:  " << Model;
		 cout << "\nYear:   " << CarYear;
		 cout << "\nMIleage:  " << Mileage;
							   
		 fclose(CarInventory);
	
		 cout << endl;
		 return 0;
}

Thanks

[mrafcho001]

this seems to be C, should've posted it in the C section.

[Daved]

^^ It combines C and C++ as the OP stated, so I guess it's fine here.

You have two FILE* variables, one called CarInventory and one called Carinventory. Case matters, and so the file pointer that is open for reading is not used, the one open for writing is instead. You should close the first file when you are done with it, then make a separate variable name for reading or just fix the typo. If you fix the typo you will get a compile error that is easy to fix - just remove the FILE* part in front of the second declaration.

[Keiyentai]

Odd...I fixed the spelling and removed the second FILE * and it still crashes...I am using BloodShed Dev-C++. THank you though for all help

[Salem]

> Hey everyone I did a tutorial on a website that seems to combines C and C++
Is it on this site?
Because it's lousy C and lousier C++.
gets() is NEVER a good sign in any language.


> I fixed the spelling and removed the second FILE * and it still crashes
Well post the latest.

[arjunajay]

> gets() is NEVER a good sign in any language.

Why?

[Keiyentai]

Here is the revise.

 // Program to perform file processing using the FILE structure
// Author: Jules Larson. Revised by Jeremy Jones 2005
#include <iostream>
using namespace std;
int main()
{
	char Make[20], Model[20];
	unsigned int CarYear;
	long Mileage;
	
	FILE *CarInventory = fopen("cars.inv", "w");
	
	cout << "Enter the following pieces of information\n";
	cout << "Make:	 "; gets(Make);
	cout << "Model:	"; gets(Model);
	cout << "Year:	"; cin >> CarYear;
	cout << "Mileage:  "; cin >> Mileage;
	
	fprintf(CarInventory, "%s\n", Make);
	fprintf(CarInventory, "%s\n", Model);
	fprintf(CarInventory, "%s\n", CarYear);
	fprintf(CarInventory, "%s\n", Mileage);

		  CarInventory = fopen("cars.inv", "r+");
	
		 fscanf(CarInventory, "%s\n", Make);
		 fscanf(CarInventory, "%s\n", Model);
		 fscanf(CarInventory, "%d\n", &CarYear);
		 fscanf(CarInventory, "%d\n", &Mileage);
		 
		 cout << "Information about the car";
		 cout << "\nMake:   " << Make;
		 cout << "\nModel:  " << Model;
		 cout << "\nYear:   " << CarYear;
		 cout << "\nMileage:  " << Mileage;
							   
		 fclose(CarInventory);
	
		 cout << endl;
		 return 0;
}

Compiles and runs just fine but after I imput the info it crashes giving me the whole "This program has ran in to an error and needs to close" blah blah typical MS stuff.

[Salem]

@ arjunajay
Read the FAQ - http://faq.cprogramming.com/cgi-bin/...&id=1043284351

@ Keiyentai
1. You don't check for errors on your fopen calls

FILE *CarInventory = fopen("cars.inv", "w");
if ( CarInventory == NULL ) {
  // do something else
} else {
  // read the file
}

> CarInventory = fopen("cars.inv", "r+");
The bigger problem here (apart from not checking for errors) is that you've still got the file open for writing, and now you're trying to open it for reading.

Try

fclose( CarInventory );
CarInventory = fopen("cars.inv", "r+");

I would suggest you stick to "r" mode until you're ready for the extra features which "+" gets you.

[Keiyentai]

arg...ok now it dies in the middle of doing work after making these changes.

 // Program to perform file processing using the FILE structure
// Author: Jules Larson. Revised by Jeremy Jones 2005
#include <iostream>
using namespace std;
int main()
{
	char Make[20], Model[20];
	unsigned int CarYear;
	long Mileage;
	
	FILE *CarInventory = fopen("cars.inv", "w");
	if (CarInventory == NULL ) {
	   // do something else
	   } else {
	   // read the file
}					 
	cout << "Enter the following pieces of information\n";
	cout << "Make:	 "; gets(Make);
	cout << "Model:	"; gets(Model);
	cout << "Year:	"; cin >> CarYear;
	cout << "Mileage:  "; cin >> Mileage;
	
	fprintf(CarInventory, "%s\n", Make);
	fprintf(CarInventory, "%s\n", Model);
	fprintf(CarInventory, "%s\n", CarYear);
	fprintf(CarInventory, "%s\n", Mileage);

		  CarInventory = fopen("cars.inv", "r+");
	
		 fscanf(CarInventory, "%s\n", Make);
		 fscanf(CarInventory, "%s\n", Model);
		 fscanf(CarInventory, "%d\n", &CarYear);
		 fscanf(CarInventory, "%d\n", &Mileage);
		 
		 cout << "Information about the car";
		 cout << "\nMake:   " << Make;
		 cout << "\nModel:  " << Model;
		 cout << "\nYear:   " << CarYear;
		 cout << "\nMileage:  " << Mileage;
							   
		 fclose(CarInventory);
		 CarInventory = fopen("cars.inv", "r+");
		 
		 return 0;
}

hmm maybe I am just not seeing something or to new to C\C++ sorry for the anoyence. Just dont know why I am getting the "Windows needs to close this program" error...mar..Thanks for the help anyways.

[Salem]

Maybe you should start with reading.
I rather expected you to intelligently apply what I said to your code, not blindly copy/paste it into what you have.

Like this for example

#include <iostream>
using namespace std;
int main()
{
    char Make[20], Model[20];
    unsigned int CarYear;
    long Mileage;

    FILE *CarInventory = fopen("cars.inv", "w");
    if (CarInventory == NULL) {
        cout << "Can't open";
    } else {
        cout << "Enter the following pieces of information\n";
        cout << "Make:	 ";
        gets(Make);
        cout << "Model:	";
        gets(Model);
        cout << "Year:	";
        cin >> CarYear;
        cout << "Mileage:  ";
        cin >> Mileage;

        fprintf(CarInventory, "%s\n", Make);
        fprintf(CarInventory, "%s\n", Model);
        fprintf(CarInventory, "%s\n", CarYear);
        fprintf(CarInventory, "%s\n", Mileage);
        fclose(CarInventory);
    }

    CarInventory = fopen("cars.inv", "r");
    if (CarInventory == NULL) {

    } else {
        fscanf(CarInventory, "%s\n", Make);
        fscanf(CarInventory, "%s\n", Model);
        fscanf(CarInventory, "%d\n", &CarYear);
        fscanf(CarInventory, "%d\n", &Mileage);

        cout << "Information about the car";
        cout << "\nMake:   " << Make;
        cout << "\nModel:  " << Model;
        cout << "\nYear:   " << CarYear;
        cout << "\nMileage:  " << Mileage;

        fclose(CarInventory);
    }
    return 0;
}

[Antigloss]

You forgot to close the file before reopening it.

fclose( CarInventory );   /* Add the close statement here */
CarInventory = fopen("cars.inv", "r+");

btw, kimi, nihonjin desuka?

[Antigloss]

also, change your code

fprintf(CarInventory, "%s\n", CarYear);
fprintf(CarInventory, "%s\n", Mileage);

to

	fprintf(CarInventory, "%d\n", CarYear);
	fprintf(CarInventory, "%d\n", Mileage);