How do I scan from a txt file (only the country names) and store them in a 2D array?

Question

Australia   67      57      54   
England     57      66      53   
Canada      26      32      34   
India       22      16      23   
NewZealand  20      12      17   
Scotland    13      11      27   
Nigeria     12      9       14   
Wales       8       6       14   
SAfrica     7       9       11    
Uganda      3       0       2
Samoa       1       4       0
BVIslands   2       0       0
Ghana       0       2       3
Namibia     0       0       4
Dominica    0       2       0

The above is the text from the text file.

Here is my code:

#define COUNTRIES 15
#define MEDALCAT 3
#define MAX_LENGTH_CNAME 100

void
readFromFile(char fileWithMedals[30], int country[COUNTRIES][MEDALCAT],
    char countryNames[COUNTRIES][MAX_LENGTH_CNAME])
{

    FILE *cWealth = fopen("commonWealth.txt", "r");
    char single = fgetc(cWealth);

    if (cWealth == NULL) {
        printf("Error! File was not created!");
        exit(1);
    }
    int line = 0;

    while (!feof(cWealth) && !ferror(cWealth)) {
        if (fgets(countryNames[line], MAX_LENGTH_CNAME, cWealth) != NULL) {
            line++;
        }
    }

    fclose(cWealth);

    for (int i = 0; i < line; i++) {
        printf("%s", countryNames[i]);
    }

    fclose(cWealth);
}

I need to somehow read and store only the country names from this. And store the column 1, 2, 3 of numbers seperately.

Answer 1

A few issues ...

1. char single = fgetc(cWealth); should be done after the if (cWealth == NULL) block.
2. It serves no purpose and would be flagged by the compiler with -Wall
3. As mentioned above use of feof [and ferror] are wrong.
4. You have "parallel" arrays (country and countryNames), indexed by the country count/index. Better to use a struct.
5. fileWithMedals is not used. Why is it length 30 (a hardwired/magic constant)?
6. I'm guessing this is the filename to open??? But, you open "commonWealth.txt"?
7. fclose is called twice. The second call will bork.

---

Here is the refactored code. It uses a struct to combine the data. It shows two ways to read the input:

1. The first method is the simplest translation of the code. But, it assumes hardwired values for MAX_LENGTH_CNAME and MEDALCAT
2. The second method allows those #define to be changed arbitrarily.

#include <stdio.h>
#include <stdlib.h>

#define COUNTRIES 15                    // max number of countries
#define MEDALCAT 3                      // max number of medals / country
#define MAX_LENGTH_CNAME 100            // maximum country name length

struct country {
    char name[MAX_LENGTH_CNAME];        // country name
    int medals[MEDALCAT];               // medals won
};

int
readFromFile(const char *fileWithMedals,struct country countries[COUNTRIES])
{

    FILE *cWealth = fopen(fileWithMedals, "r");

    if (cWealth == NULL) {
        printf("Error! File was not created!");
        exit(1);
    }

    int count = 0;

    char buffer[1000];
    struct country *country;
    int *medals;

    while (fgets(buffer,sizeof(buffer),cWealth) != NULL) {
        // too many countries? should we error out here?
        if (count >= COUNTRIES)
            break;

        country = &countries[count];
        medals = country->medals;

        // syntax error -- should we error out here?
        if (sscanf(buffer,"%99s %d %d %d",
            country->name,&medals[0],&medals[1],&medals[2]) != 4)
            continue;

        ++count;
    }

    fclose(cWealth);

    for (int i = 0; i < count; i++) {
        country = &countries[i];
        medals = country->medals;
        printf("%s %d %d %d\n",
            country->name,medals[0],medals[1],medals[2]);
    }

    return count;
}

int
readFromFile2(const char *fileWithMedals,struct country countries[COUNTRIES])
{

    FILE *cWealth = fopen(fileWithMedals, "r");

    if (cWealth == NULL) {
        printf("Error! File was not created!");
        exit(1);
    }

    int count = 0;

    struct country *country;
    int *medals;

    // given that MAX_LENGTH_CNAME is 100, we want a format of "%99s" for
    // safety with fscanf
    char namefmt[10];
    sprintf(namefmt,"%%%ds",MAX_LENGTH_CNAME - 1);

    while (1) {
        // too many countries? should we error out here?
        if (count >= COUNTRIES)
            break;

        country = &countries[count];
        medals = country->medals;

        if (fscanf(cWealth,namefmt,country->name) != 1)
            exit(1);

        for (int i = 0;  i < MEDALCAT;  ++i) {
            if (fscanf(cWealth,"%d",&medals[i]) != 1)
                exit(2);
        }

        ++count;
    }

    fclose(cWealth);

    for (int i = 0; i < count; i++) {
        country = &countries[i];
        medals = country->medals;

        printf("%s",country->name);

        for (int j = 0;  j < MEDALCAT;  ++j)
            printf(" %d",medals[j]);

        printf("\n");
    }

    return count;
}

int
main(int argc,char **argv)
{

    --argc;
    ++argv;

    if (argc != 1) {
        fprintf(stderr,"need filename\n");
        exit(1);
    }

    struct country countries[COUNTRIES];

    printf("ORIGINAL:\n");
    readFromFile(argv[0],countries);

    printf("\nMODIFIED:\n");
    readFromFile2(argv[0],countries);

    return 0;
}

---

For the given input file, here is the program output:

ORIGINAL:
Australia 67 57 54
England 57 66 53
Canada 26 32 34
India 22 16 23
NewZealand 20 12 17
Scotland 13 11 27
Nigeria 12 9 14
Wales 8 6 14
SAfrica 7 9 11
Uganda 3 0 2
Samoa 1 4 0
BVIslands 2 0 0
Ghana 0 2 3
Namibia 0 0 4
Dominica 0 2 0

MODIFIED:
Australia 67 57 54
England 57 66 53
Canada 26 32 34
India 22 16 23
NewZealand 20 12 17
Scotland 13 11 27
Nigeria 12 9 14
Wales 8 6 14
SAfrica 7 9 11
Uganda 3 0 2
Samoa 1 4 0
BVIslands 2 0 0
Ghana 0 2 3
Namibia 0 0 4
Dominica 0 2 0