Problem with some code

This is a discussion on Problem with some code within the C Programming forums, part of the General Programming Boards category; Here is my code. The problem is when I run the Addrecords function the first time it works, but the ...

  1. #1
    Registered User
    Join Date
    Nov 2001
    Posts
    6

    Question Problem with some code

    Here is my code. The problem is when I run the Addrecords function the first time it works, but the next time I run it, it goes straight back to the main menu. I don't understand why!

    Can someone have a look and see if they can spot why....





    /* Header files defined */
    #include <stdio.h>

    /* Constants defined */
    #define makemax 50
    #define modelmax 50
    #define yearregmax 10
    #define regmarkmax 10
    #define mileagemax 10
    #define pricemax 10
    #define maxrecords 30

    /* Structed defined */
    struct carrecords
    {
    char make[makemax];
    char model[modelmax];
    char yearreg[yearregmax];
    char regmark[regmarkmax];
    char mileage[mileagemax];
    char price[pricemax];
    int used;

    }record[maxrecords];

    /* Variables defined */
    int i, k, count;
    char quit, option;
    int makel, modell, yearregl, regmarkl, mileagel, pricel;

    /* File Pointer defined */
    FILE *fp;


    /* Function to add records to that database */
    void addrecord(void)
    {
    if ((fp = fopen("car.data", "a+b"))==NULL) /* Opens the database file for writing to */
    {
    printf("\n\nCannot open file!\n\n"); /* Error statement if database file can not be opened */
    }

    else
    {
    char sync = getchar(); /* Captures carriage return from menu */
    fread(&record, sizeof(struct carrecords), maxrecords, fp); /* Reads database file into structure records */


    for (k=0;k <= maxrecords;k++)
    {
    if (record[k].used & 1) /* Searches through the structure for first available record */
    {
    ;
    }
    else
    {
    break; /* Breaks when it finds an available record. */
    }
    }

    for(i = k; quit != 'q'; i++) /* Starts at that available record to enter record data */
    {

    printf("\n\nEnter details for each car\n\n");

    printf("Make of Car: ");
    fgets(record[i].make, makemax, stdin);
    makel = strlen(record[i].make);
    record[i].make[makel - 1] = '\0';

    printf("Model of Car: ");
    fgets(record[i].model, modelmax, stdin);
    modell = strlen(record[i].model);
    record[i].model[modell - 1] = '\0';

    printf("Year of Registration: ");
    fgets(record[i].yearreg, yearregmax, stdin);
    yearregl = strlen(record[i].yearreg);
    record[i].yearreg[yearregl - 1] = '\0';

    printf("Registration Number: ");
    fgets(record[i].regmark, regmarkmax, stdin);
    regmarkl = strlen(record[i].regmark);
    record[i].regmark[regmarkl - 1] = '\0';

    printf("Car Mileage: ");
    fgets(record[i].mileage, mileagemax, stdin);
    mileagel = strlen(record[i].mileage);
    record[i].mileage[mileagel - 1] = '\0';

    printf("Price: ");
    fgets(record[i].price, pricemax, stdin);
    pricel = strlen(record[i].price);
    record[i].price[pricel - 1] = '\0';

    record[i].used = 1;

    printf("\nPress q to display records or Enter to enter more data:");
    scanf("%c", &quit);
    }
    }
    fwrite(&record, sizeof(struct carrecords), maxrecords, fp); /* Writes the structure to the database file */
    fclose(fp); /* Closes the file */
    main(); /* Goes back to the main menu */
    }

    void browserecord(void)
    {
    if ((fp = fopen("car.data", "r+b"))==NULL)
    {
    printf("\n\nCannot open file!\n\n");
    main();
    }

    fread(&record, sizeof(struct carrecords), maxrecords, fp);

    for(i=0; i<=maxrecords; i++)
    {
    printf("%s, %s, %s, %s, %s, %s\n", record[i].make, record[i].model, record[i].yearreg, record[i].regmark, record[i].mileage, record[i].price);
    }

    fclose(fp);

    }


    int main(void)
    {
    printf("\nCar Database\n");
    printf("===============================\n");
    printf("1. Add Records\n");
    printf("2. Browse Records\n");
    printf("3. Exit Program\n");
    printf("\n");

    while(1)
    {

    printf("Please enter an option 1,2 or 3: ");
    scanf("%s", &option);

    switch(option)
    {
    case '1':
    addrecord();
    break;
    case '2':
    browserecord();
    break;
    case '3':
    exit(0);
    break;
    default:
    printf("\n\nBad Input. Please try again!\n\n");
    break;

    }
    }

    }

  2. #2
    apparitionzero
    Guest
    i suggest using "return;" to exit a void function rather than calling another instance of "main()"

  3. #3
    Registered User C_Coder's Avatar
    Join Date
    Oct 2001
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    523
    Yeah calling main inside a function gave me loads of problems when I tried it, *shudders* never again!!!
    Last edited by C_Coder; 03-16-2002 at 01:47 PM.
    All spelling mistakes, syntatical errors and stupid comments are intentional.

  4. #4
    Registered User
    Join Date
    Nov 2001
    Posts
    6
    Yes thanks for that will use return instead of calling main.

    However it still doesn't solve my problem.
    Any more ideas?

    Thanks

    Zac

  5. #5
    Registered User C_Coder's Avatar
    Join Date
    Oct 2001
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    523
    The problem is when I run the Addrecords function the first time it works, but the next time I run it, it goes straight back to the main menu.
    Is this still the problem? When I ran your code(changed the calls to main to return statements) Addrecords was called correctly each time, allowing me to enter as many car details as I wanted, well as many as maxrecords would allow.
    All spelling mistakes, syntatical errors and stupid comments are intentional.

  6. #6
    Registered User
    Join Date
    Jan 2002
    Posts
    11

    car records

    Hello there,
    maybe I am being stupid but your code does not write to disk, you need to change the file open line to "a:\\cardata.bin,rb
    this will test for your file name on the drive you specify and create it if it is not already there.

    Change the a:\\ to c:\\ if you want it on your hard disk. Then add some data,and open the data file in notepad to verify that it contains data .

    I did this and the data is written to disk. However I could not view the records, I think some additional code is needed here, can you reply if you still want some help with this program.
    If its not 5.00p.m. on Friday its crap!!

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