Thread: Struct + File

Hi, I got this problem when I was running my code. I am a beginner in this field so it'd be great to know what is the problem in my code. The error is when I finished putting in my input, it could not read my input and my filename.txt stopped working.

Code:

#include <stdio.h>#include <stdlib.h>


typedef struct details
{
    char plateNo[50];
    char vehicleType[50];
    char carBrand[50];
    int date;
    int driverID;
    char ticketNo[50];
}details;




int main ()
{
    details b;
        
    FILE *fpwrite,* fpread;
    
    fpwrite - fopen ("data_test.txt", "w");    
    if( fpwrite == NULL )
    {
        printf("Error! File not found");
        exit(1);
    }
    newEntry :
     
    printf("\n---New Details---");
    
    printf("\nPlate No. : ");
    gets(b.plateNo);
    
    printf("\nVehicle Type : ");
    scanf("%s", &b.vehicleType);
    
    printf("\nCar Brand : ");
    scanf("%s", &b.carBrand);
    
    printf("\nDate : (example: DD/MM/YY) \n");
    scanf("%d", &b.date);
    
    printf("\nDriver ID : ");
    scanf("%d", &b.driverID);
    
    printf("\nTicket Issued : ");
    scanf("%d", &b.ticketNo);
    
    fflush (stdin);
    fwrite(&b,sizeof(b),10,fpwrite);
    fclose(fpwrite);
    
    fpread = fopen("data_test.txt", "r");
    while (fread(&b, sizeof(b),10,fpread) > 0)
        printf("%s\n %s\n %d\n %d\n %d\n",b.plateNo,b.vehicleType,b.carBrand,b.date,b.driverID,b.ticketNo);
    fclose(fpread);
}

Oh my gosh, goodness me.
I got a lot of errors here and there, thank you so much

Hallo,

Salem is right, you can use

Code:

scanf("%49[^\n]", b.plateNo);

This line reads all character including the space(ASCII 32dec)
The number 49 limits the length of the input to 49 Bytes to prevent a overflow.
Example:

Code:

#include <stdio.h>
#include <stdlib.h>

void clpuf(void)
 {
 while (getc(stdin) != '\n')
    ;
 }

int main()
{
 int i;
 char c_posi[200],  c_nega[200];

 for (i = 0; i < 200; i++)
      c_posi[i] = c_nega[i] = 0;

 printf("Example Positiv- and negativ Liste with scanf\n");

 printf("\nPlease for example enter a String like \nexample.....: 123430abc  \nEnter string:  ");

/**  reads only characters where between the braces, and finishes the inputwhen the first character was read in where not in this list */
 scanf("%[0123456789+-*/=]", c_posi);
 printf("The Input was:: %s \n\n", c_posi);

 /** clears keyboard buffer */
 clpuf();

 printf("\nPlease for example enter a String like \nexample.....: asdfgh123  \nEnter string:  ");
  scanf("%[^1234567890]", c_nega);
 printf("The Input was: %s \n\n", c_nega);

 clpuf(); /** clears keyboard buffer*/

 printf("\nPlease enter a string witch includes space-character\nEnter:  ");
 /** reads all characters, but not the newline-sign(Enter)*/
 scanf("%199[^\n]", c_nega);
 printf("The Input was: %s \n\n", c_nega);

 printf("End of Program\n");
return EXIT_SUCCESS;
}

Hi Syazzz

here an example to write ONE set of details:

Code:

 
typedef struct details
{
    char plateNo[50];
    char vehicleType[50];
    char carBrand[50];
    int date;
    int driverID;
    char ticketNo[50];
}details;
 
 void clpuf(void)
 {
 while (getc(stdin) != '\n')
    ;
 }

 
 
 
int main()
{
    details b;
    char datname[100] = {0};
    FILE *fpwrite,* fpread;
    int watu = 21;
    
    strcpy(datname,"data_test.txt"); 

 do     
 switch (watu)
 {
   default:
         printf("\n---structreadrest\n");
         printf("\nEnd of Program............0\n");
         printf("\nread file.................2\n");
         scanf("%d", & watu); 
         clpuf();
       break;
  
  case 0:
         printf("\nEnd of Program\n");
         return 0;
       break;  
     

  case 1:
    //newEntry :
    printf("\n---New Details---");
     
    printf("\nPlate No. : ");
    scanf("%[^\n]", b.plateNo);
  
    clpuf();
     
    printf("\nVehicle Type : ");
    scanf("%[^\n]", b.vehicleType);
    
    clpuf();
         
    printf("\nCar Brand : ");
    scanf("%[^\n]", b.carBrand);
     
    clpuf(); 
     
    printf("\nDate : (example: DD/MM/YY) \n");
    scanf("%d", &b.date);
     
    clpuf(); 
     
    printf("\nDriver ID : ");
    scanf("%d", &b.driverID);
     
    clpuf(); 
     
    printf("\nTicket Issued : ");
    scanf("%[^\n]", b.ticketNo);
     
    clpuf();
    
    printf("\nTry to create %s\n", datname);
    fpwrite = fopen (datname, "w");    
    if( fpwrite == NULL )
    {
        printf("Error! File not found");
        return(0);
    }
    
    fwrite(&b,sizeof(struct details),1,fpwrite);
    fclose(fpwrite);
    watu = 21;
   break; 
    
case 2: 
    printf("\nTry to read    %s\n", datname);     
    fpread = fopen(datname, "r");
    if (fpread == NULL) 
     { 
      printf("\nError open file\n"); 
      watu = 21;
      break; 
     } 
   
 while (fread(&b, sizeof(struct details),1, fpread))
    {  
     printf("Plate No.... :  %s\n",  b.plateNo);
     printf("Vehicle Type :  %s\n",  b.vehicleType); 
     printf("Car Brand... :  %s\n",  b.carBrand); 
     printf("Date ....... :  %d\n ", b.date);
     printf("Driver ID... :  %d\n",  b.driverID);
     printf("Ticket Issued:  %s\n",  b.ticketNo);  
    }
    fclose(fpread);
    
        
     watu = 21;
   break;  
   
   
 }while(watu != 0);
 printf("\nEnd of Program\n"); 
 return 0;   
}

the row

Code:

while(fread(&bc[i++], sizeof(struct buch3), 1, infile))

writes 1 time a set of details.
When you have a fixed number like 10, it could be happen that
the Program writes any nonsens as data and you will have an error
when you will try to read the file.

rusyoldguy & Syazzz:

Instead of using:

Code:

scanf("%[^\n]", b.plateNo);

I strongly urge the use of fgets() instead and then remove the newline form the end of the string.

scanf() is fine for inputing numbers, but please use fgets() for strings. And please use #defines instead of "Magic Numbers"

Code:

#define DIM 50
...
char plateNo[DIM];
...
// Not
...
char plateNo[50];
...