Thread: File IO

I want to scan a text file:

Code:

jones,1,2,3,4
smith,2,3,4,5
john,57,65,4,2
catherine,25,64,78,65

I want ask a few questions:
(1) Can anybody give me any functions on how I can use to do this (or point me in the general direction).
I tried using fscanf, but it keeps on giving me the wrong answers.
Below is the code

Code:

#include <stdio.h>

#define MAXSTUDENT 40
#define MAXNAME 20

typedef struct student_t{
char name[(MAXNAME+1)];
int exam1,exam2, exam3, exam4;
float average;
};

int main(void)
{                 
FILE *readfile;
int num=4;                            
int check;
student_t student[MAXSTUDENT] = {0};

int i;
                              
if((readfile=fopen("datafile.txt","rt"))==NULL)
{
printf("Error, unable to read file.  Program exiting");
return (1);
}else
 {
 

 for(i=0,check=0;i<num;i++)
 {
 
    do
    {
    check=fscanf(readfile,"%s,%d,%d,%d,%d",&student[i].name,&student[i].exam1,&student[i].exam2,&student[i].exam3,&student[i].exam4);
    printf(".");                   
    }while(check==4);
    
    printf("*");
  }
printf("\n%d",student[0].exam1);
printf("\n%d",student[0].exam2);
printf("\n%d",student[0].exam3);
printf("\n%d",student[0].exam4);

}

return 0;
}

Thanks in advance.

I am still stuck. How would you tell fscanf to read a new line from the data and store it?
I can't give it a value like EOF, since this would mean the end of the file, not a new line.

Again, thanks in advance =).

I've tried changing &student[i].name to student[i].name, but i still can't read the file. The compiler gives something like:
"Data if 'int' supplied where pointer is required"

Code:

#include <stdio.h>

#define MAXSTUDENT 40
#define MAXNAME 20

typedef struct student_t{
char name[(MAXNAME+1)];
int exam1,exam2, exam3, exam4;
float average;
};

int main(void)
{                 
FILE *readfile;
int num=4;                            
int check; 
int i=0;
student_t student[MAXSTUDENT] = {0};


                              
if((readfile=fopen("datafile.txt","rt"))==NULL)
{
printf("Error, unable to read file.  Program exiting");
return (1);
}else
 {
 



   while((fscanf(readfile,"%s,%d,%d,%d,%d",student[i].name,student[i].exam1,student[i].exam2,student[i].exam3,student[i].exam4)!=EOF))
        {
        printf(".");                 
        i++;
        }
      
    


printf("\n%d",student[0].exam1);
printf("\n%d",student[0].exam2);
printf("\n%d",student[0].exam3);
printf("\n%d",student[0].exam4);

}
fclose(readfile);

return 0;
}

For some reason, fscanf seams to be only taking a whole line from the text file and storing it in the string member of the structure. But I want the line to be stored in seperately into different members in the structure. Below is my code:

Code:

#include <stdio.h>

#define MAXSTUDENT 40
#define MAXNAME 20

typedef struct{
char name[(MAXNAME+1)];
int exam1,exam2, exam3, exam4;
float average;
}student_t;

int main(void)
{                 
FILE *readfile;
                            
student_t student [MAXSTUDENT]; 
int i=0;



                              
if((readfile=fopen("datafile.txt","rt"))==NULL)
{
printf("Error, unable to read file.  Program exiting");
return (1);
}else
 {
 



   while((fscanf(readfile,"%s,%d,%d,%d,%d",student[i].name,&student[i].exam1,&student[i].exam2,&student[i].exam3,&student[i].exam4)!=EOF))
        {
        printf(".");                 
        ++i;
        }
      
    


printf("\n%s",student[0].name);
printf("\n%d",student[0].exam1);
printf("\n%d",student[0].exam2);
printf("\n%d",student[0].exam3);
printf("\n%d",student[0].exam4);

}
fclose(readfile);

return 0;
}

However for the print out i seem be getting something like this:

Code:

jones,1,2,3,4 //for student[0].name
0                    //for student[0].exam1
2011641991  //for student[0].exam2
2                    //for student[0].exam3
66                  //for student[0].exam4

But I want it to be something like this:

Code:

jones             //for student[0].name
1                    //for student[0].exam1
2                    //for student[0].exam2
3                    //for student[0].exam3
4                    //for student[0].exam4

Would somebody please help? I've been stuck on this for hours. =(

Thanks.

Well, it's because he is getting everything as string, I suggest you in the file change it to something like this:

Code:

jones 1 2 3 4

And not jones,1,2,3,4.

Also in fscanf you don't need those ',' just use it as:

Code:

fscanf(readfile,"%s%d%d%d%d",student[i].name,&student[i].exam1,&student[i].exam2,&student[i].exam3,&student[i].exam4)

Yes, i know that placing spaces in between would make it easier. But i want to know why it doesn't work it I use the comma operator?

If it does, how can I make fscanf read the line of text?

I tried your code on my compiler, but it doesn't work.

I tried it on my computer at home and now it works. Thanks very much! =)