C - Storing Values from text into Arrays

Question

I'm trying to store different values that are taken from a file line by line. The lines in the text file read as something shown below

100000,player1,long title name
300000,someotherplayer,another long title name
45512845,thisplayer,one more long title name

I want to store each value that is comma separated into three different arrays, (int)number, (str)player_name, (str)title_name.

I have some code below, but it doesn't compile.

ptr_file=fopen("text.txt", "r");
char buffer[1000];
int line;
line = 0;

while(fgets(buffer, sizeof(buffer), ptr_file) != NULL){
    char number[line]=strtok(buffer, ",");  
    char player_name[line]=strtok(NULL, ",");
    char title_name[line]=strtrok(NULL, ",");
}

Can someone give me some advice on this?

Have you forgot the * before identifier in your variable declarations? — Jack
– Jack, Commented Nov 23, 2012 at 4:07
"o" is wrong, but it's runtime error. ptrfile vs. ptr_file is surely compile time error. and contents of the loop is some kind of heresy — keltar
– keltar, Commented Nov 23, 2012 at 4:09

Gille · Accepted Answer · 2012-11-23 04:18:51Z

2

So, there are a couple of issues with your code,

You open the file in mode "o" which I'm not really sure what it is, I suspect you want "r" strtok returns a char * which you cannot assign to a char[]. One the second run through the loop you will overwrite the data in buffer. I would do something like this:

struct player {
    int number;
    char player_name[64];
    char title_name[256];
};

int main(void) {
    FILE *ptrfile=fopen("text.txt", "r");
    char buffer[1000];
    int line;
    struct player players[16];
    line = 0;
    if(ptrfile==NULL) return 0;
    while(fgets(buffer, sizeof(buffer), ptrfile) != NULL){
        if(strcmp(buffer, "") == 0) return 0;
        char *number=strtok(buffer, ",");
        char *player_name=strtok(NULL, ",");
        char *title_name=strtok(NULL, ",");
        players[line].number=atoi(number);
        strcpy(players[line].player_name, player_name);
        strcpy(players[line].title_name, title_name);;
        line++;
    }
    fclose(ptrfile);
    return 0
}

answered Nov 23, 2012 at 4:18

Gille

5,7831 gold badge19 silver badges16 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Jonathan Leffler Over a year ago

Officially, you should check the memory allocations, or comment that you're ignoring error checking.

lenik · Accepted Answer · 2012-11-23 04:09:05Z

1

function strtok return a pointer, so it should be

char* p = strtok(...)

Check the reference here

edited Nov 23, 2012 at 4:09

lenik

23.6k4 gold badges38 silver badges44 bronze badges

answered Nov 23, 2012 at 4:07

Matt

6,06027 silver badges37 bronze badges

Comments

bigfetz · Accepted Answer · 2012-11-23 04:19:49Z

1

This is something I did that was similar to what you seem to be doing. The problem you will find is that you want to make each value into a char* but you have to malloc each one then you can connect this char* into the array. It would also just be easier to do that with the numbers to then turn them into int later on.

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

    int main()
    {
        char *msg[100]; 
        char temp[100];
        int length, i;
        int num = 0;


        while((scanf("%s", &temp[0]) != EOF))
        {
            length = strlen(temp);
            msg[num] = malloc((length+1 )* sizeof(char));
            strcpy(msg[num], temp);
            num++;
        }

        printf("There are %d words in the this input.\n", num);

        for(i = 0; i < num; i++)
        {
            printf("%s\n", msg[i]);
        }
        return 0;
    }

The thing with the malloc is that you will have to have each one unique because the words are all different sizes. I know this example isn't exactly what your doing but it will get you in the right direction.

answered Nov 23, 2012 at 4:19

bigfetz

3271 gold badge5 silver badges12 bronze badges

1 Comment

Jonathan Leffler Over a year ago

Officially, you should check the memory allocations, or comment that you're ignoring error checking.

Collectives™ on Stack Overflow

C - Storing Values from text into Arrays

3 Answers 3

1 Comment

Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

1 Comment

Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related