fwrite() not working to write integer in binary file

Question

Can someone tell my why won\'t this function work? I just can\'t get it...

void writeRegister(FILE *arq, Book *L){ //writes in actual file position
  char          


        

Answer 1

the following code:

1) eliminates the bad practice of typedef'ing a struct
2) removed the mis-leading all caps of the struct field names
3) contains the needed #includes
4) contains the needed prototypes for the external (in another file) functions
5) checks for the worst of the many possible runtime errors
6) replaces the mis-leading 'L' with a meaningful name
7) modifies the file pointer variable to a commonly known name

suggest compiling with all warnings enabled (and fix the warnings)
for gcc, at a minimum, use '-Wall -Wextra -pednatic'


#include 
#include 
#include 



struct Book
{
    char *title;
    char *author;
    char *publisher;
    int   year;
    char *language;
    int   pages;
    float price;
};

int reglen( struct Book * );
int readData( struct Book * );


void writeRegister(FILE *fp, struct Book *myBook)
{ //writes in actual file position
    char c = '|';
    int sizeRegWrite = reglen(myBook); //reglen() returns the size of Book
    fwrite(&sizeRegWrite, sizeof(int), 1, fp);

    fwrite(myBook->title, sizeof(char), strlen(myBook->title), fp);
    fwrite(&c, sizeof(char), 1, fp); //writing delimiter

    fwrite(myBook->author, sizeof(char), strlen(myBook->author), fp);
    fwrite(&c, sizeof(char), 1, fp); //writing delimiter

    fwrite(myBook->publisher, sizeof(char), strlen(myBook->publisher), fp);
    fwrite(&c, sizeof(char), 1, fp); //writing delimiter

    fwrite(&(myBook->year), sizeof(int), 1, fp);
    fwrite(&c, sizeof(char), 1, fp); //writing delimiter

    fwrite(myBook->language, sizeof(char), strlen(myBook->language), fp);
    fwrite(&c, sizeof(char), 1, fp); //writing delimiter

    fwrite(&(myBook->pages), sizeof(int), 1, fp);
    fwrite(&c, sizeof(char), 1, fp); //writing delimiter

    fwrite(&(myBook->price), sizeof(float), 1, fp);
    fwrite(&c, sizeof(char), 1, fp); //writing delimiter
    return;
} // end function: writeRegister


int main( void )
{
    FILE *fp = fopen("BD_books2.bin", "rb");
    if(fp == NULL)
    {
        perror( "fopen for BD_books2.bin failed" );
        exit( EXIT_FAILURE );
    }

    // implied else, fopen successful

    struct Book myBook;
    int goodRead = readData(&myBook); //Reads all fields from keyboard and places in Book. Working properly
    if( goodRead )
    {
        writeRegister(fp, &myBook);
    }

    system("pause");
    return 0;
} // end function: main