Thread: Need help; stuck with this; read file + compare with user input

Hi all,

I'm stuck with another problem.
I'm trying to make a multiple choice quiz.

Each question has 2 answers, one of them is the right one (A or B).

The questions + answers are stored in a .txt file like this;

What is football?;A car;A game;B

Now i want my code to stop showing the line at

What is football?;A car;A game

and let the user input A or B, then compare with the last character of the line in my file, which is ;A or ;B.

Here's my code;

Code:

void spelen(void)


{
   static const char filename[] = "vragen.txt"; /* the name of a file to open */
   FILE *file = fopen(filename, "r+"); /* try to open the file */
   if ( file )
   {
      char line[BUFSIZ]; /* space to read a line into */
      int k = 0;
      while ( fgets(line, sizeof line, file) ) /* read each line */
      {
         int i;
         char *token = line; /* point to the beginning of the line */
         printf("line %d:\n", ++k);
         for ( i = 0; *token; ++i ) /* loop through each character on the line */
         {
            /* search for delimiters */
            size_t len = strcspn(token, ";\n"); 
            /* print the found text: use *.* in format to specify a maximum print size */
            printf("[%2d] = \"%*.*s\"\n", i, (int)len, (int)len, token);
             /* advance pointer by one more than the length of the found text */
            token += len + 1;
         }
      }
      fclose(file);
   }

}

and here's my output:

Code:

[0]What is football?
[1]A car
[2]A game
[3]B

Any advice, tips or help with this would be great.

Thanks in advance

How can i copy the details (from the file);

Code:

What is football;A game; A car; A

to this structure?

Code:

struct quiz {
   char question[100];         (What is a football)
   char answers[2][100];     (A game)(A car)                                       
   char correct;                     (A)

well i tried with this but still can't figure it out.. :

Code:

struct vragen {   
	 char vraag[MAXVRAAG];
	 char  antw[MAXANTW];
	 char  antw1[MAXANTW];
	 char  keuze[2];
};

Code:

void spelen(void)


{
   static const char filename[] = "vragen.txt"; /* the name of a file to open */
   FILE *file = fopen(filename, "r+"); /* try to open the file */
   if ( file )
   {
      char line[BUFSIZ]; /* space to read a line into */
      int k = 0;
      while ( fgets(line, sizeof line, file) ) /* read each line */
      {
         sscanf(vragen, "%s %s %s %s",
         vragen.vraag,
         vragen.antw,
         vragen.antw1,
         vragen.keuze);
      }
      fclose(file);
   }
   printf("%s", vragen.vraag)
}

Originally Posted by vart

you haven't defined a variable of type struct vragen
I think you should define array of structs in the calling function
and pass it as an argument to the spelen function
also in your while loop you should iterate through the array to fill new struct on each iteration

i don't quite get this, could you give me an example?

thanks in advance

Originally Posted by vart

something like

Code:

int main()
{
	struct vragen quiz[100];
	spelen(quiz,100);
}

void spelen(struct vragen* quiz, int maxQ)
{
	int index = 0;
	...
	while ( fgets(line, sizeof line, file) ) /* read each line */
      {
         sscanf(vragen, "%s %s %s %s",
         quiz[i].vraag,
         quiz[i].antw,
         quiz[i].antw1,
         quiz[i].keuze);
		 i++;
		 if(i == maxQ)
			 break;
      }
...
}

Thanks vart, this works like a charm!
You gave me the insight, thanks for your time & effort!

If someone is wondering; I changed my code to:

Code:

 struct vragen quiz[100]; 
   int i;   
   static const char filename[] = "vragen.txt"; /* the name of a file to open */
   FILE *file = fopen(filename, "r+"); /* try to open the file */
   if ( file )
   {
      char line[BUFSIZ]; /* space to read a line into */
      int i = 0;
      while ( fgets(line, sizeof line, file) ) /* read each line */
      {
         sscanf(line, "%[^]%[^;];%[^;];%[^;]",
         quiz[i].vraag,
         quiz[i].antw,
         quiz[i].antw1,
         quiz[i].keuze);
         i++;
         if(i == MAXVRAAG) break;
      }
      fclose(file);

Originally Posted by vart

what is the MAXVRAAG constant?
I thought it was used in the

char vraag[MAXVRAAG];

to determine the longets question?
Then using it in the loop is out of place
You should use another const QUIZ_COUNT and use it in two place - where you declare the array
struct vragen quiz[QUIZ_COUNT];
and where you check that there is no memory overrun
if(i == QUIZ_COUNT ) break;

MAXVRAAG is from

#define MAXVRAAG 30

and used for the maximum amount of characters in a question (char vraag[MAXVRAAG]).

I've made another const though, MAX 30, and used MAX for the loop, is this ok?