I'm trying to create an array of structs that will expand as the user wants to input more. Here is the struct:

struct employee{
    char name[20];
    int id;
    char job[35];
    float basePay;
    float overTimePay;
    float totalPay;
    float totalPayBenefits;
    int year;
    char agency[15];
    int count;
};

I have implemented the expanding struct array here (this will continue adding structs to the array for as long as the user specifies to do so):

struct employee *createEmployees(){
    //Declare and initialize necessary variables
    int i = 1;
    char continueChar = 'y';
    struct employee *employeeList = malloc(sizeof(employeeList));
    //While user selects continue
    while(continueChar == 'y'){
        char temp;
        //reallocate based on how many times the user has continued
        if(i != 1){
            employeeList = realloc(employeeList, i * sizeof(employeeList));
        }
        printf("Enter Employee %d name: ", i);
        //Clear char from input
        scanf("%c",&temp);
        //Set employee name
        scanf("%[^\n]", employeeList[i-1].name);
        //Get user continue selection
        printf("Would you like to enter another employee? (y/n): ");
        scanf(" %c", &continueChar);
        i  ;
    }
    //Keep a count of all employees in list in the first employee cell
    employeeList[0].count = i - 1;
    //Return formed employees struct array
    return employeeList;
}

When I test that all the names are set in main it appears that they are. The count also is correct in main. My problem comes when I pass this array of structs to a separate function to read a file and input the contents into the struct array. Here is main:

int main(){
    //Declare an array to hold all employees
    struct employee *employeeList = createEmployees();
    //Get userID from txt file
    getID(employeeList);
}

And here is getID (This function will search the entire employeeInformation.txt file until it finds a match for the given name. It will repeat this X times where X is the count stored in employeeList[0].count):

void getID(struct employee *employeeList){
    char line[100];
    int stop = 1;
    FILE *fptr = fopen("employeeInformation.txt", "r");
    if(!fptr){
        perror("Error");
        exit(0);
    }
    //skip first line
    fgets(line, 100, fptr);
    for(int i = 0; i < employeeList[0].count; i  ){
        while (!feof(fptr) && stop) {
            int id;
            char name[20];
            char job[35];
            fscanf(fptr, "%d\t%[^\t]%[^\n]", &id, &name, &job);
            printf("%d\t%s\t%s\n", id, name, job);
            if(strcmp(employeeList[i].name, name) == 0){
                employeeList[i].id = id;
                strcpy(employeeList[i].job, job);
                stop = 0;
            }
            fgets(line, 100, fptr);
        }
        fseek(fptr, 0, SEEK_SET);
        stop = 1;
    }
    fflush(fptr);
    fclose(fptr);
}

So my problem is that employeeList[0].count doesn't seem to be passing correctly. I can get the count correctly in main and before I open a file within the getID method, but after I open a file it says the value is equal to some very long number. I think the problem is in one of two places; either I'm allocating the struct array incorrectly or I'm passing the struct array incorrectly. I've tried numerous methods to try to fix this but I just can't seem to wrap my head around what the issue is. Any help with this would be greatly appreciated!

CodePudding user response：

What's the sizeof(employeeList)?

struct employee *employeeList = malloc(sizeof(employeeList));

Try this:

struct employee *employeeList = malloc(sizeof(*employeeList));

CodePudding user response：

1. Memory allocation isn't right.

/* create employee list with 4 elements */
size_t members_count = 4;
struct employee *employeeList = malloc(sizeof(struct employee) * members_count); 

2. Always(!!!) check what malloc returns

/* create employee list with 4 elements */
size_t members_count = 4;
struct employee *employeeList = malloc(sizeof(struct employee) * members_count);
if (NULL == employeeList)
    return;

3. If you want to increase dynamically number of members better choose other data structure for that. Not array. Take a look at lists. Because array should be placed in continuous block and this not good for memory in some cases.