First record returning null??
Hi,
I'm having some trouble with this file which ultimately needs linking to two other files, Stock, and Order.
The problem is that after adding the first record, I debug the code posted below and it doesn’t seem to recognize the first record I added, which causes trouble when adding the second record. It adds the node correctly which causes the cycle to go through the correct number of times, but when it gets to the last cycle it is returned a NULL value, which is supposed to be the first record I added.
Can anyone spot the flaw in the code?
Code:
#include <stdio.h>
#include
#include <string.h>
#include
FILE *fSupplier;
void DisplaySupplierMenu();
void SearchBySupplierCode();
void AddSupplierRecord();
void AmendSupplierRecord();
bool SearchSupplier();
void DisplaySearchedSupplierRecord();
bool WriteNewSupplierRecord();
void LoadSupplierRecord(struct SupplierRefer **q);
void AddSupplierNode(struct SupplierRefer **q, int num);
void AssignSupplierRefer(struct SupplierRefer **p);
void OpenSupplierFile();
void CloseSupplierFile();
int CurrSupplierRecNum=0;
int TotalSupplierNode=0;
char SearchedSupplierCode[7];
struct Supplier{
char SupplierCode[7];
char SupplierName[21];
char SupplierAddress[21];
char SupplierPhone[11];
};
struct Supplier Supplier;
struct SupplierRefer{
char SupplierCode[7];
struct SupplierRefer *Supplierlink;
};
struct SupplierRefer *mySupplierrefer;
int main() {
mySupplierrefer=(struct SupplierRefer*)malloc(sizeof(struct
SupplierRefer));
LoadSupplierRecord(&mySupplierrefer);
bool isExit=false;
while (!isExit) {
DisplaySupplierMenu();
char ch;
gets(&ch);
switch (ch) {
case '1':
SearchBySupplierCode();
break;
case '2':
AddSupplierRecord();
break;
case '3':
AmendSupplierRecord();
break;
case '0':
isExit=true;
}
}
return 0;
}
void DisplaySupplierMenu() {
puts(" \n");
puts(" * 1 : View Supplier Record *\n");
puts(" * 2 : Add Supplier Record *\n");
puts(" * 3 : Amend Supplier Record *\n");
puts(" * 0 : Exit *\n");
puts(" \n");
}
void OpenSupplierFile() {
fSupplier=fopen("a:\\Supplier.txt", "r+");
if (fSupplier==0) {
fSupplier=fopen("a:\\Supplier.txt", "w");
fclose(fSupplier);
fSupplier=fopen("a:\\Supplier.txt", "r+");
}
}
void CloseSupplierFile() {
fclose(fSupplier);
}
void SearchBySupplierCode() {
OpenSupplierFile();
puts("Enter Supplier Code For The Record You Want To
Search\n");
gets(SearchedSupplierCode);
if (SearchSupplier()) {
DisplaySearchedSupplierRecord();
CloseSupplierFile();
return;
}
else {
printf("Supplier Code Wasn't Found");
return;
}
}
void DisplaySearchedSupplierRecord() {
long offset;
printf("Searched Record Details\n");
offset=sizeof(Supplier)* CurrSupplierRecNum;
fseek(fSupplier,offset,0);
fread(&Supplier, sizeof(Supplier), 1, fSupplier);
puts("\nSupplier Code");
puts(Supplier.SupplierCode);
puts("\nSupplier Name");
puts(Supplier.SupplierName);
puts("\nSupplier Address");
puts(Supplier.SupplierAddress);
puts("\nSupplier Phone");
puts(Supplier.SupplierPhone);
printf("\nSearched Successfully");
}
void AddSupplierRecord() {
puts("\nEnter New Supplier Code\n");
gets(SearchedSupplierCode);
OpenSupplierFile();
while(true) {
if (SearchSupplier()) {
printf("\nEntered Supplier Code Already Exixts\n");
puts("\nEnter New Supplier Code\n");
gets(SearchedSupplierCode);
}
else {
if (WriteNewSupplierRecord()) {
AddSupplierNode(&mySupplierrefer, TotalSupplierNode);
CloseSupplierFile();
return;
}
else {
CloseSupplierFile();
return;
}
}
}
CloseSupplierFile();
}
bool WriteNewSupplierRecord() {
long offset;
char temp_name[21];
char temp_address[21];
char temp_phone[11];
offset=sizeof(Supplier)* TotalSupplierNode;
fseek(fSupplier, offset, 0);
fflush(stdin);
if(strlen(SearchedSupplierCode)== 6) {
strcpy(Supplier.SupplierCode, SearchedSupplierCode);
puts("Enter Value For Supplier Name, Should Have Atleast
Single Character\n");
gets(temp_name);
if(strlen(temp_name)>0 & strlen(temp_name)<21) {
strcpy(Supplier.SupplierName, temp_name);
puts("Enter Value For Supplier Address\n");
gets(temp_address);
if(strlen(temp_address)>0 & strlen(temp_address)<21) {
strcpy(Supplier.SupplierAddress, temp_address);
puts("Enter Value For Supplier Phone Number, Should Be
Between 1-10 Characters");
gets(temp_phone);
if(strlen(temp_phone)>0 & strlen(temp_phone)<11) {
strcpy(Supplier.SupplierPhone, temp_phone);
fwrite(&Supplier, sizeof(Supplier), 1, fSupplier);
puts("New Record Added Successfully");
return true;
}
else {
puts("Enterd Supplier Phone Number Is Not Valid, Should
Be Between 1-10 Characters");
return false;
}
}
else {
puts("Enterd Supplier Address Is Not Valid, Should Be
Between 1-20 Characters");
return false;
}
}
else {
puts("Enterd Supplier Name Is Not Valid, Should Be Between
1-20 Characters, Should Have Atleast Single
Character");
AddSupplierRecord();
}
}
else {
puts("Enterd Supplier Code Is Not Valid, Should Be 6
Characters\n");
AddSupplierRecord();
}
}
void AmendSupplierRecord() {
long offset;
char temp_name[21];
char temp_address[21];
char temp_phone[11];
fflush(stdin);
puts("\nEnter Supplier Code You Want To Amend\n");
gets(SearchedSupplierCode);
OpenSupplierFile();
if (SearchSupplier()) {
offset=sizeof(Supplier)* CurrSupplierRecNum;
fseek(fSupplier, offset, 0);
fread(&Supplier, sizeof(Supplier), 1, fSupplier);
puts(Supplier.SupplierName);
puts("\nEnter New Value For Supplier Name\n");
gets(temp_name);
if(strlen(temp_name)>0 & strlen(temp_name)<21)
strcpy(Supplier.SupplierName, temp_name);
else {
printf("Entered Supplier Name Is Not Valid, Should Be
Between 1-20 Characters");
return;
}
puts(Supplier.SupplierAddress);
puts("Enter New Value For Supplier Address\n");
gets(temp_address);
if(strlen(temp_address)>0 & strlen(temp_address)<21)
strcpy(Supplier.SupplierAddress, temp_address);
else {
printf("Entered Supplier Address Is Not Valid, Should Be
Between 1-20 Characters");
return;
}
puts(Supplier.SupplierPhone);
puts("Enter New Value For Supplier Phone Number\n");
gets(temp_phone);
if(strlen(temp_phone)>0 & strlen(temp_phone)<11)
strcpy(Supplier.SupplierPhone, temp_phone);
else {
printf("Entered Supplier Phone Number Is Not Valid, Should
Be Between 1-10 Characters");
return;
}
fseek(fSupplier, offset, 0);
fwrite(&Supplier, sizeof(Supplier),1,fSupplier);
fflush(stdin);
puts("Record Successful Amended");
CloseSupplierFile();
LoadSupplierRecord(&mySupplierrefer);
}
else {
printf("Searched Supplier Code Does Not Exist");
fflush(stdin);
}
}
bool SearchSupplier() {
int index=0;
struct SupplierRefer *temp;
temp=mySupplierrefer->Supplierlink;
if (TotalSupplierNode==0 ) {
puts("File Is Empty.");
return false;
}
while (index<=TotalSupplierNode-1) {
if (strcmp(SearchedSupplierCode,temp->SupplierCode)==0) {
CurrSupplierRecNum=index;
return true;
}
else {
index+=1;
temp=temp->Supplierlink;
}
}
return false;
}
bool FindSupplierName() {
OpenSupplierFile();
return false ;
}
void LoadSupplierRecord(struct SupplierRefer **q) {
long offset;
struct SupplierRefer *temp;
temp=*q;
TotalSupplierNode=0;
OpenSupplierFile();
while(true) {
if(fread(&Supplier, sizeof(Supplier),1,fSupplier)==1) {
if (temp==NULL) {
temp=(struct SupplierRefer*)malloc(sizeof(struct
SupplierRefer));
AssignSupplierRefer(&temp);
}
else {
temp->Supplierlink=(struct SupplierRefer*)malloc(sizeof
(struct SupplierRefer) );
temp=temp->Supplierlink;
AssignSupplierRefer(&temp);
}
}
else {
CloseSupplierFile();
break;
}
}
return;
}
void AssignSupplierRefer(struct SupplierRefer **p) {
struct SupplierRefer *temp;
temp=*p;
long offset=sizeof(Supplier)*TotalSupplierNode;
fseek(fSupplier, offset, 0);
fread(&Supplier, sizeof(Supplier), 1,fSupplier);
strcpy(temp->SupplierCode,Supplier.SupplierCode);
TotalSupplierNode+=1;
return;
}
void AddSupplierNode(struct SupplierRefer **q, int num) {
int index;
struct SupplierRefer *temp;
if (TotalSupplierNode==0 || *q==NULL) {
*q=(struct SupplierRefer*)malloc(sizeof(struct SupplierRefer));
temp=*q;
AssignSupplierRefer(&temp);
return;
}
else {
while(index<=TotalSupplierNode) {
temp=temp->Supplierlink;
}
temp=(struct SupplierRefer*)malloc(sizeof(struct
SupplierRefer) );
AssignSupplierRefer(&temp);
}
return;
}
