CODEWITHSUNDEEP
cstructio
user47835
user47835

Reputation: 159

reading data from an input file and storing it into a struct array

I plan on reading an input file that has a name and a number separated by an indent such as 

Ben     4
Mary    12
Anna    20
Gary    10
Jane    2

and then later perform a heap sort on the data. I'm having trouble copying the data and storing it into a struct array however.

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define maxcustomers 100

struct customer{
    char name[20];
    int service;
};

int main()
{
    struct customer list[maxcustomers];
    int i;
    char c;

    FILE *input;
    FILE *output;
    input = fopen("input-file.txt","r");
    output = fopen("output-file.txt","w");

    if(input == NULL){
        printf("Error reading file\n");
        exit(0);
    }
    else{
        printf("file loaded.");

    }
    while((c=fgetc(input))!=EOF){
           fscanf(input, "%s %d", &list[i].name,&list[i].service);

           printf("%s %d", list[i].name,list[i].service);
           i++;
    }
    fclose(input);
    //heapsort(a,n);
    //print to output.txt
    fclose(output);

    return 0;
}

so far it registers it opens a file and prints "file loaded" but fails after. im obviously not saving data to the struct.

Upvotes: 2

Views: 101

Answers (2)

t.elazari
t.elazari

Reputation: 280

in addition to what @Keine Lust said, i have no initial value, you cant use/increment integer without value as you did.

try: int i=0

Upvotes: 3

David Ranieri
David Ranieri

Reputation: 41017

You are consuming/walking the file with both fgetc and fscanf, use only fscanf:

while (fscanf(input, "%19s %d", list[i].name, &list[i].service) == 2) {
       printf("%s %d", list[i].name, list[i].service);
       i++;
}

Notice that you don't need the address of operator in &list[i].name because it is already (decays into) a pointer.

Upvotes: 5

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