Storing data from text file into array?

Hi, I'm having trouble storing information from a text file into an array. I have the code working fine if it stores into non-array variables, but as soon as I try to use an array the program stalls. Can somebody point out the issue?

Code that works without array

Code:

---

        FILE *fp = fopen("students.txt", "r");
        int stu;
        char name[30];
        double t1, t2, a, labs, exams;
       
        fscanf(fp, "%d,%lf,%lf,%lf,%lf,%lf,%[A-Za-z /]", &stu, &t1, &t2, &a, &labs, &exams, name);
        printf("%d,%s,%lf,%lf,%lf,%lf,%lf", stu, name, t1, t2, a, labs, exams);

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Code that fails with array

Code:

---

        FILE *fp;
        fp = fopen("students.txt", "r");
        int stu[MAX_SIZE], i = 0;
        char name[MAX_SIZE][20];
        double t1[MAX_SIZE], t2[MAX_SIZE], a[MAX_SIZE],
        labs[MAX_SIZE], exams[MAX_SIZE];
       

        fscanf(fp, "%d,%lf,%lf,%lf,%lf,%lf,%[A-Za-z /]", stu[i], t1[i], t2[i], a[i], labs[i], exams[i], name[i]);
        printf("%d %s %lf %lf %lf %lf %lf", stu[i], name[i], stu[i], t1[i], t2[i], labs[i], exams[i]);

---

The file is structured in this format:

Code:

---

00101010,80.0,79.0,88.0,67.0,90.0,Bob Newhart
00111010,88.0,77.0,66.0,57.0,56.0,Alex Trebek
00121010,80.0,79.0,88.0,67.0,90.0,Stephen Harper
00131010,88.0,77.0,66.0,57.0,56.0,Alfred Newman

---

Code:

---

fscanf(fp, "%d,%lf,%lf,%lf,%lf,%lf,%s",&stu[i], &t1[i],&t2[i],&a[i], &labs[i],&exams[i], name[i]);

---

You forgot something. Also, compile with warnings on.


Quzah.

Thought that the ampersand was omitted for arrays, forgot that only applies to strings.

Thanks a bunch.

Check the return value of fscanf.

Code:

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for( x = 0; x < arrayelements; x++ )
{
    if( fscanf( ... ) != numberexpected && feof( ... ) )
        break;
}

---

Something like that would be fine. Optionally, you could add the colored condition there too.

Quzah.

Yeah, found that right before you posted haha.

Once last question :P

I've completed the program and it compiles and runs fine in Windows with MinGW. When I try to compile it through my school's Linux cluster, it compiles fine but I get a Segmentation Fault whenever I try to run it. Any idea?

Please do tell if you need to see the code or not. My school has a pretty strict policy and I don't want to get kicked out 2 semesters down the road out of some slim chance they see that I posted my program online :P

See if it dumps a .core file, and debug it with gdb. It should help you find out what function it's in when it crashes.


Quzah.

Quote:

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Originally Posted by flaris

Thought that the ampersand was omitted for arrays, forgot that only applies to strings.

Thanks a bunch.

---

Ampersand IS omitted for arrays since an array name by itself is already an address of sorts. This applies whether it's a char array, int array, double array, whatever.
But in the fscanf() case, you are referencing array[i] - a specific element. Not an address. So you need to use the ampersand after all.