Constant pointer array with struct fields that may point to malloc allocated fields?
int main() {
Employee *array[SIZE]; //Employee is a typedef struct --includes char *name, DATE *dateOfBirth, DATE is also a typedef struct, has 3 int fields month, day, year,`
fillArray(array, &count, fpin1, fpin2);
freeMemory(array, int count);
}
fillArray(Employee *array[], int *count, FILE *fpin1, FILE *fpin2)
char buffer[MAX], buffer2[MAX];
while (fgets(buffer, MAX, fpin1) != NULL && fgets(buffer2, MAX, fpin2) != NULL){
array[*count]->name = (char *) malloc(sizeof(char)*25);
assert(array[*count]->name != NULL);
strncpy(array[*count]->name, buffer, 15);
strncpy(buffer2, temp, 2);
array[*count]->dateOfBirth->day = atoi(temp)
}
The code compiles but keeps failing w开发者_开发百科ith segmentation fault, it seems to fail at my fgets? or my malloc, what am I doing wrong? I really can't seem to figure that out.
Also how would you go about freeing this memory in a
freeMemory(Employee *array[], int count)
function?
Should be:
int main() {
Employee array[SIZE]; //Employee is a typedef struct --includes char *name, DATE *dateOfBirth, DATE is also a typedef struct, has 3 int fields month, day, year,`
fillArray(&array, &count, fpin1, fpin2);
freeMemory(&array, int count);
}
You aren't allocating your Employee
objects anywhere, so array[0] points to some random address.
Employee* array[SIZE];
This is an array that stores pointers to Employee
structs.
I think you mean
fillArray(Employee* array[], int* count, FILE *fpin1, FILE *fpin2)
{
char buffer[MAX], buffer2[MAX];
int i = 0;
while ( fgets(buffer, MAX, fpin1) != NULL &&
fgets(buffer2, MAX, fpin2) != NULL )
{
// the array does not hold any valid memory address.
array[i] = malloc( sizeof(Employee) );
assert( array[i] != NULL );
// now on the new employee add some char memory
(array[i])->name = malloc( sizeof(char) * 25 );
assert(array[i]->name != NULL);
strncpy(array[i]->name, buffer, 15);
strncpy(buffer2, temp, 2);
array[i]->dateOfBirth->day = atoi(temp)
++i;
(*count)++;
}
}
doing array[*count]
besides looking weird, always modifies the same index. You never modified *count
anywhere.
This code does not check that you do not exceed the bounds of the array
passed.
Also : for the freeMemory()
freeMemory(Employee* array[], int count)
{
int i = 0;
while( i < count )
{
free(array[i]);
array[i] = NULL;
++i;
}
}
精彩评论