Reading from a File to an Array - C

Question

int main()
{

    FILE* infile1;

    int stockCode[15];
    char stockName[100];
    int stockQuantity[15];
    int stockReorder[15];
    int unitPrice[15];
    int i;

    infile1  = fopen("NUSTOCK.TXT", "r");

    while(fscanf(infile1, "%d %s %d %d %f",
         &stockCode, stockName, &stockQuantity, &stockReorder, &unitPrice) != EOF)
    {
        printf("  %3d  %-18s  %3d  %3d  %6.2f \n",
          stockCode, stockName, stockQuantity, stockReorder, unitPrice);
    }

    fclose(infile1);

}

What I'm trying to do is to take information from a file and store it into 5 separate arrays. However, when printing out, it only prints out the name correctly.

1394854864 Prune-Basket 1394854688 1394854624 0.00
1394854864 Pear-Basket 1394854688 1394854624 0.00
1394854864 Peach-Basket 1394854688 1394854624 0.00
1394854864 Deluxe-Tower 1394854688 1394854624 0.00

The original file looks like this. So all the numbers aren't being scanned in and I can't figure out why...

101 Prune-Basket 065 060 25.00
105 Pear-Basket 048 060 30.00
107 Peach-Basket 071 060 32.00
202 Deluxe-Tower 054 040 45.00

QJGui · Accepted Answer · 2014-03-06 03:03:00Z

2

I think what you want to do is designing a structure for saving many personal records. And each record contain:

code
name
quantity
reorder
unitPrice

You should know the meaning of each type in C language.

I suggest you rewrite your codes like these:

#include <stdio.h>
#include <stdlib.h>
struct OneRecord{
    int code;
    char name[100];
    int quantity;
    int recorder;
    float unitPrice;
};

int main(){


    struct OneRecord* records = (struct OneRecord*)calloc(15, sizeof(struct OneRecord));
    int i = 0;

    FILE* infile1  = fopen("NUSTOCK.TXT", "r");
    int max=0;

    //%99s is used for max string length, because of we can protect the out of string's memory length
    while((max<15)&&(fscanf(infile1, "%d %99s %d %d %f",
                &records[i].code, records[i].name, &records[i].quantity, &records[i].recorder, &records[i].unitPrice) == 5))
    {
        i++;
        max++;
    }
    for(i=0;i<max;i++){
        printf("  %3d  %-18s  %3d  %3d  %6.2f \n",
                records[i].code,records[i].name,records[i].quantity,records[i].recorder,records[i].unitPrice);
    }

    fclose(infile1);
    free(records);
}

And how to use the C Structure in functions or many other places? In C programming language, there are different types such as int, char, struct and so on. You can use struct like many other types.

void printRecords(const struct OneRecord* records, int max)
{
    int i;
    for(i=0;i<max;i++){
        printf("  %3d  %-18s  %3d  %3d  %6.2f \n",
                records[i].code,records[i].name,records[i].quantity,records[i].recorder,records[i].unitPrice);
    }
}

edited Mar 6, 2014 at 3:03

answered Mar 5, 2014 at 2:54

QJGui

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3 Comments

chux Over a year ago

Minor: Suggest ""%d %99s %d %d %f"" and while (fscanf(...) == 5)

user3357457 Over a year ago

Thank you! I didn't think of using a structure and after researching to understand a bit more I think I got it. My next question is, how would I use that structure in a function I write?

QJGui Over a year ago

@user3357457 Please see the example. You can use struct like many other types.

Lee Duhem · Accepted Answer · 2014-03-05 05:24:56Z

1

You are using those arrays incorrectly. Try this:

i = 0;
while(fscanf(infile1, "%d %s %d %d %f",
            stockCode+i, stockName, stockQuantity+i, stockReorder+i, unitPrice+i) != EOF)
{
    printf("  %3d  %-18s  %3d  %3d  %6.2f \n",
            stockCode[i], stockName, stockQuantity[i], stockReorder[i], unitPrice[i]);
    i++;
}

Also, the unitPrice should be a array of float, not of int.

edited Mar 5, 2014 at 5:24

answered Mar 5, 2014 at 2:18

Lee Duhem

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1 Comment

Lee Duhem Over a year ago

@chux Yes, you are right. I forgot to mention that.

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