Reading a file in a table format and print it - c

Question

So, what I'm trying to do is, at first create a file in a table format then read that file and put that file in 4 different dynamic arrays using struct and print them in order
So, here is the struct I'm using: I used capacity = 5 to change the size of dynamic array later but still don't know how to change it
struct score{
char *str1;
char *str2;
int *num1;
int *num2;
};
int main(){
int capacity = 5;
struct score table;
table.str1=(char *)malloc(sizeof(int)*capacity);
table.str2=(char *)malloc(sizeof(int)*capacity);
table.num1=(int *)malloc(sizeof(int)*capacity);
table.num2=(int *)malloc(sizeof(int)*capacity);
After I created a File to write:
inFile = fopen("Subject.txt", "w");
if(inFile == NULL)
{
printf("Error!");
exit(1);
}
char names[] = {"Joe Math 52 85\nBilly Phy 65 70\nSophia Chem 86 71"};
fprintf(inFile,"%s",names);
fclose(inFile);
At the end reading a File and putting them in arrays:
inFile = fopen("Subject.txt", "r");
if(inFile == NULL)
{
printf("Error!");
exit(1);
}
fscanf(inFile, "%s %s %d %d",table.str1, table.str2, table.num1, table.num2);
fclose(inFile);
for(i=0;i<6;i++){
printf("%s %s %d %d\n",table.str1, table.str2, table.num1, table.num2);
}
So, I need this code to print like this, and I couldn't do it:
Name Subj. Test1 Test2
------------------------
Joe Math 52 85
Billy Phy 65 70
Sophia Chem 86 71
Here is my full Code just in case:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
struct score{
char *str1;
char *str2;
int *num1;
int *num2;
};
int main(){
FILE *inFile;
int num, capacity = 5, i;
struct score table;
table.str1=(char *)malloc(sizeof(int)*capacity);
table.str2=(char *)malloc(sizeof(int)*capacity);
table.num1=(int *)malloc(sizeof(int)*capacity);
table.num2=(int *)malloc(sizeof(int)*capacity);
inFile = fopen("Subject.txt", "w");
if(inFile == NULL)
{
printf("Error!");
exit(1);
}
char names[] = {"Joe Math 52 85\nBilly Phy 65 70\nSophia Chem 86 71"};
fprintf(inFile,"%s",names);
fclose(inFile);
inFile = fopen("Subject.txt", "r");
if(inFile == NULL)
{
printf("Error!");
exit(1);
}
fscanf(inFile, "%s %s %d %d",table.str1, table.str2, table.num1, table.num2);
fclose(inFile);
for(i=0;i<6;i++){
printf("%s %s %d %d\n",table.str1, table.str2, table.num1, table.num2);
}
}

Answer 1

You want an array of structs.
But, you've got a fixed number of scores (e.g. num1, num2). This, also, should be an array.
I think you'll be better off with a second struct. That is, struct student and struct score
And, Paul outlined how to do this with fixed limits.
In general, you could allocate things dynamically to accomodate an arbitrary number of students that have an arbitrary (and varying) number of test scores.
Based on your sample data, your input format is:
<name> <subject> <score1> <score2> ... <scoreN>
Because of this, I interpret the subject to be the students major, so it gets grouped in the student record.
Otherwise, we'd need something like:
<name> <subject1> <score1> <subject2> <score2> ... <subjectN> <scoreN>
And, then, the subject would go into the score record
To get it to work, I had to [heavily] refactor your code:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
struct score {
int score;
};
struct student {
char *name;
char *subject;
struct score *scores;
int count;
};
int
main(void)
{
FILE *inFile;
struct student *students = NULL;
int student_count = 0;
struct student *who;
struct score *score;
const char *delim = " \t\n";
char *cp;
char buf[1000];
inFile = fopen("Subject.txt", "w");
if (inFile == NULL) {
printf("Error!");
exit(1);
}
char names[] = { "Joe Math 52 85\nBilly Phy 65 70\nSophia Chem 86 71" };
fprintf(inFile, "%s", names);
fclose(inFile);
inFile = fopen("Subject.txt", "r");
if (inFile == NULL) {
printf("Error!");
exit(1);
}
while (1) {
// get a line
cp = fgets(buf,sizeof(buf),inFile);
if (cp == NULL)
break;
// get the student name
cp = strtok(buf,delim);
if (cp == NULL)
continue;
// allocate new student record
students = realloc(students,
sizeof(struct student) * (student_count + 1));
who = &students[student_count];
student_count += 1;
// save the student name
who->name = strdup(cp);
// get the subject and save it
cp = strtok(NULL,delim);
if (cp == NULL)
break;
who->subject = strdup(cp);
// clear out the scores array
who->count = 0;
who->scores = NULL;
// get all scores
while (1) {
cp = strtok(NULL,delim);
if (cp == NULL)
break;
// increase the size of the scores array for this student
who->scores = realloc(who->scores,
sizeof(struct score) * (who->count + 1));
score = &who->scores[who->count];
who->count += 1;
score->score = atoi(cp);
}
}
fclose(inFile);
for (who = &students[0]; who < &students[student_count]; ++who) {
printf("%10s %10s", who->name, who->subject);
for (score = who->scores; score < &who->scores[who->count]; ++score)
printf("%4d",score->score);
printf("\n");
}
return 0;
}
Here's the program output:
Joe Math 52 85
Billy Phy 65 70
Sophia Chem 86 71

Answer 2

I think you want an array of structs with one array element for each student. Now you are using one struct to hold arrays of the individual pieces of information.
The array would look like:
#define MAX_NAME 30
#define MAX_STUDENTS 10
struct score{
char str1[MAX_NAME];
char str2[MAX_NAME];
int num1;
int num2;
};
struct score table[MAX_STUDENTS];
With this definition you don't need to malloc memory (it is simpler, but not flexible).
You read the information into the array as:
int i=0;
while (fscanf(inFile, "%30s %30s %d %d",table[i].str1, table[i].str2,
&table[i].num1, &table[i].num2) == 4) {
i++;
}