I'm learning about disjoint dynamic memory, so I'm trying to make my own program. I need someone to help me see my problems and show me how to fix them.
I'm almost done with my program, but still have some problems in my program. My problem: my saveData() function and reload() function do not work correctly.
- I'm not sure whether the saveData() function does get all the data I need
- my reload() function just output it has brought back data from the bin file (in saveData() function) and then exit program with some weird code (ex: 8500241654)
Without the above problem, my program works well. Please check the 3 problems in my program in .h file and .c file
C Program Description:
"You will write a program that will store the information about automobiles. The information is about make, mode, yearBuilt, and cost (use struct). The user will choose from menu what they want to do (add auto, display auto with orders of cost or make, use switch).
When the program begins, if there was a previous data file of automobile information it will be loaded automatically. The program will begin where the user last left off. If there is no previous data file, then the program will ask the user how many automobiles record will be needed and the program will start fresh.
When the program ends, all data will be saved to a bin file. All memory will be released from the heap. "
P/s: thank you so much, and appreciate your help. <Here is my .h file>
// FUNCTION PROTOTYPES
typedef struct {
char make[50]; // ex: Ford, Honda, Toyota
char model[50]; // ex: Corolla, Camry
int yearBuilt; // ex: 2001, 2022
int cost; // ex: 20500, 8999, 15000
} AUTOMOBILE; // 108 bytes
void addAuto(AUTOMOBILE* a[], int* eSize, int size);
int compareChars(const void* a, const void* b);
void displayAuto(AUTOMOBILE* autos[], int eSize);
void displayMenu();
void freeMemory(AUTOMOBILE* autos[], int size);
int getInt(char m[]);
int getCh(char m[]);
void quitProgram(int* temp);
AUTOMOBILE** reload(AUTOMOBILE* a[], int* eSize, int* size);
void saveData(AUTOMOBILE *a[], int eSize, int size);
void sortByCost(AUTOMOBILE* autos[], int eSize);
void sortByMake(AUTOMOBILE* autos[], int eSize);
// FUNCTIONS
void addAuto (AUTOMOBILE *a[], int* eSize, int size) {
char again = 'N';
char autoMake[50];
char autoModel[50];
do {
if (*eSize == size) {
printf("No room to add more automobile...it is full!\n");
system("pause");
return;
}
printf("\nAdding a new automobile to the array of items\n");
// add make
printf("What is the automobile's make (uppercase first letter, ex: Honda)? ");
scanf("%s", a[*eSize]->make);
// add model
printf("What is the automobile's model (uppercase first letter, ex: Camry)? ");
scanf("%s", a[*eSize]->model);
// add year built
a[*eSize]->yearBuilt = getInt("When was the automobile built (ex: 2022)? ");
// add cost
a[*eSize]->cost = getInt("How much does the automobile cost (ex: 45500)? ");
*eSize += 1;
printf("\nWould you like to add another item? [Y/N]: ");
scanf(" %c", &again);
} while (toupper(again) == 'Y');
} // end addAuto
int compareChars(const void* a, const void* b) {
const char* arg1 = *(const char**) a;
const char* arg2 = *(const char**) b;
return strcmp(arg1, arg2);
} // end compareChars
void displayAuto(AUTOMOBILE *autos[], int eSize) {
char option;
printf("\nChoose your desired order");
printf("\n[C]ost low to high");
printf("\n[M]ake ascending order");
option = getCh("\nEnter option: ");
if (option == 'C' || option == 'c')
sortByCost(autos, eSize);
else if (option == 'M' || option == 'm')
sortByMake(autos, eSize);
} // end displayAuto
void displayMenu() {
printf("\n[A]dd one automobile");
printf("\n[D]isplay all automobiles by");
printf("\n\t[C]ost low to high");
printf("\n\t[M]ake ascending order"); // ascending order: A-Z
printf("\n[Q]uit program\n");
} // end displayMenu
void freeMemory(AUTOMOBILE* autos[], int size) {
for (int i = 0; i < size; i++) {
free(autos[i]);
}
free(autos);
} // end freeMemory
int getCh(char m[]) {
char result;
char badValue = 'F';
// loop until get integer value
do {
badValue = 'F';
printf("%s", m);
scanf(" %c", &result);
// if "result" isn't an alphabet, do the loop again
if (isalpha(result) == 0) {
printf("\nYou must enter a valid character!\n");
badValue = 'T';
} // end If
} while (badValue == 'T');
return result;
} // end getCh
int getInt(char m[]) {
int result = 0;
char badValue = 'F';
// loop until get integer value
do {
badValue = 'F';
printf("%s", m);
if (scanf("%i", &result) != 1) {
printf("\nYou must enter a valid real numeric value!\n");
badValue = 'T';
} // end If
} while (badValue == 'T');
return result;
} // end getInt
void quitProgram(int *temp) {
printf("\nThank you for using program!\n");
*temp = 1;
} // end quitProgram
AUTOMOBILE** reload(AUTOMOBILE* a[], int* eSize, int* size) {
*eSize = 0;
FILE* fp = fopen("binaryDocument.bin", "rb");
if (fp == NULL) {
printf("\nNo information has been reload!\n");
system("pause");
return a;
} // end if
printf("\nI have brought back the previous saved data into the array!\n");
system("pause");
// get the size
fread(size, sizeof(int), 1, fp);
// memory allocation for [size] pointers, [size] * 4 bytes of space
// use the size to allocate the space for the pointer array
a = calloc(*size, sizeof(AUTOMOBILE*));
if (a == NULL) {
printf("Allocation of memory failed...\n");
exit(-1);
}
// go through each one of them, and allocate 108 bytes each and allow these pointers to refer to it
for (int i = 0; i < size; i++) {
a[i] = calloc(1, sizeof(AUTOMOBILE));
if (a[i] == NULL) {
printf("Allocation of memory at autos[%i] failed...\n", i);
exit(-1);
}
}
// get the eSize and use the eSize to reload the array
fread(eSize, sizeof(int), 1, fp);
fread(a, sizeof(AUTOMOBILE*), *eSize, fp);
fclose(fp);
return a;
} // end reload
void saveData(AUTOMOBILE *a[], int eSize, int size) { // PROBLEM HERE
FILE* fp = fopen("binaryDocument.bin", "wb");
if (fp == NULL) {
printf("\nCould not save the information to a binary file\n");
system("pause");
return;
} // end if
fwrite(&size, sizeof(int), 1, fp);
fwrite(&eSize, sizeof(int), 1, fp);
fwrite(a, sizeof(AUTOMOBILE*), eSize, fp);
fclose(fp);
} // end saveData
void sortByCost(AUTOMOBILE *autos[], int eSize) {
int temp = 0;
int autoCost[1000];
for (int i = 0; i < eSize; i++) {
autoCost[i] = autos[i]->cost;
}
for (int i = 0; i < eSize; ++i) {
for (int j = i + 1; j < eSize; ++j) {
if (autoCost[i] > autoCost[j]) {
temp = autoCost[i];
autoCost[i] = autoCost[j];
autoCost[j] = temp;
}
}
}
printf("\nAutomobiles are displayed from low to high in term of cost: \n");
for (int l = 0; l < eSize; l++) {
for (int k = 0; k < eSize; k++) {
if(autoCost[l] == autos[k]->cost)
printf("%i\t%s\t%s\t%i\n", autoCost[l], autos[k]->make, autos[k]->model, autos[k]->yearBuilt);
}
}
} // end sortByCost
void sortByMake(AUTOMOBILE *autos[], int eSize) {
qsort(autos, eSize, sizeof(AUTOMOBILE*), compareChars);
printf("\nAutomobiles are displayed A-Z: \n");
for (int i = 0; i < eSize; i++) {
printf("%s\t%s\t%i\t%i\n", autos[i]->make, autos[i]->model, autos[i]->yearBuilt, autos[i]->cost);
}
} // end sortByMake
<Here is my .c file>
#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "DJDMHeader.h"
//****************************************************
// MAIN FUNCTION
int main() {
int size = 0;
int eSize = 0;
AUTOMOBILE** autos = NULL; // create the variable to make the array of automobile pointers
int i, temp = 0;
char choice;
// reload data
autos = reload(autos, &eSize, &size);
// case: nothing to reload, start fresh
if (size == 0) {
// get integer value for variable size
size = getInt("How many automobiles will you have at the most: ");
// memory allocation for [size] pointers, [size] * 4 bytes of space
autos = calloc(size, sizeof(AUTOMOBILE*));
if (autos == NULL) {
printf("Allocation of memory failed...\n");
exit(-1);
}
// go through each one of them, and allocate 108 bytes each and allow these pointers to refer to it
for (i = 0; i < size; i++) {
autos[i] = calloc(1, sizeof(AUTOMOBILE));
if (autos[i] == NULL) {
printf("Allocation of memory at autos[%i] failed...\n", i);
exit(-1);
}
}
}
while (temp == 0) {
displayMenu();
choice = getCh("What is your choice?: ");
// switch
switch (choice) {
case 'a':
case 'A':
addAuto(autos, &eSize, size);
break;
case 'd':
case 'D':
displayAuto(autos, eSize);
break;
case 'q':
case 'Q':
quitProgram(&temp);
break;
default:
printf("\nPlease choose the existed choices!\n");
}
}
// Save data
saveData(autos, eSize, size);
// Free memory
freeMemory(autos, size);
return 0;
}
If anything about my program or my question make you unhappy (or something like that), please tell me, I will edit again. So much thanks.
