#include struct clientData { unsigned int acctNum; char lastName[15]; char firstName[10]; double balance; }; unsigned int enterChoice(void); void textFile(FILE* readPtr); void updateRecord(FILE* fPtr); void newRecord(FILE* fPtr); void deleteRecord(FILE* fPtr); int main(void) { FILE* cfPtr; if ((cfPtr = fopen("accounts.dat", "rb+")) == NULL) { puts("File could not be opened."); } else { unsigned int choice; while ((choice = enterChoice()) != 5) { switch (choice) { case 1: textFile(cfPtr); break; case 2: updateRecord(cfPtr); break; case 3: newRecord(cfPtr); break; case 4: deleteRecord(cfPtr); break; default: puts("Incorrect choice"); break; } } fclose(cfPtr); } } void textFile(FILE* readPtr) { FILE* writePtr; if ((writePtr = fopen("accounts.txt", "w")) == NULL) { puts("File could not be opened."); } else { rewind(readPtr); fprintf(writePtr, "%-6s%-16s%-11s%10s\n", "Acct", "Last Name", "First Name", "Balance"); while (!feof(readPtr)) { struct clientData client = { 0, "", "", 0.0 }; int result = fread(&client, sizeof(struct clientData), 1, readPtr); if (result != 0 && client.acctNum != 0) { fprintf(writePtr, "%-6d%-16s%-11s%10.2f\n", client.acctNum, client.lastName, client.firstName, client.balance); } } fclose(writePtr); } } void updateRecord(FILE* fPtr) { printf("%s", "Enter account to update (1 - 100): "); unsigned int account; scanf("%d", &account); fseek(fPtr, (account - 1) * sizeof(struct clientData), SEEK_SET); struct clientData client = { 0, "", "", 0.0 }; fread(&client, sizeof(struct clientData), 1, fPtr); if (client.acctNum == 0) { printf("Account #%d has no information.\n", account); } else { printf("%-6d%-16s%-11s%10.2f\n\n", client.acctNum, client.lastName, client.firstName, client.balance); = printf("%s", "Enter charge (+) or payment (-): "); double transaction; scanf("%lf", &transaction); client.balance += transaction; printf("%-6d%-16s%-11s%10.2f\n", client.acctNum, client.lastName, client.firstName, client.balance); fseek(fPtr, (account - 1) * sizeof(struct clientData), SEEK_SET); fwrite(&client, sizeof(struct clientData), 1, fPtr); } } void deleteRecord(FILE* fPtr) { printf("%s", "Enter account number to delete (1 - 100): "); unsigned int accountNum; scanf("%d", &accountNum); fseek(fPtr, (accountNum - 1) * sizeof(struct clientData), SEEK_SET); struct clientData client; fread(&client, sizeof(struct clientData), 1, fPtr); if (client.acctNum == 0) { printf("Account %d does not exist.\n", accountNum); } else { fseek(fPtr, (accountNum - 1) * sizeof(struct clientData), SEEK_SET); struct clientData blankClient = { 0, "", "", 0 }; fwrite(&blankClient, sizeof(struct clientData), 1, fPtr); } } void newRecord(FILE* fPtr) { printf("%s", "Enter new account number (1 - 100): "); unsigned int accountNum; scanf("%d", &accountNum); fseek(fPtr, (accountNum - 1) * sizeof(struct clientData), SEEK_SET); struct clientData client = { 0, "", "", 0.0 }; fread(&client, sizeof(struct clientData), 1, fPtr); if (client.acctNum != 0) { printf("Account #%d already contains information.\n? ", client.acctNum); scanf("%14s%9s%lf", &client.lastName, &client.firstName, &client.balance); client.acctNum = accountNum; fseek(fPtr, (client.acctNum - 1) * sizeof(struct clientData), SEEK_SET); fwrite(&client, sizeof(struct clientData), 1, fPtr); } } unsigned int enterChoice(void) { printf("%s", "\nEnter your choice\n" "1 - store a formatted text file of accounts called\n" " \"accounts.txt\" for printing\n" "2 - update an account\n" "3 - add a new account\n" "4 - delete an account\n" "5 - end program\n? "); unsigned int menuChoice; scanf("%u", &menuChoice); return menuChoice; } Can someone explain this to me. This is C Programming
#include <stdio.h>
struct clientData {
unsigned int acctNum;
char lastName[15];
char firstName[10];
double balance;
};
unsigned int enterChoice(void);
void textFile(FILE* readPtr);
void updateRecord(FILE* fPtr);
void newRecord(FILE* fPtr);
void deleteRecord(FILE* fPtr);
int main(void) {
FILE* cfPtr;
if ((cfPtr = fopen("accounts.dat", "rb+")) == NULL) {
puts("File could not be opened.");
}
else {
unsigned int choice;
while ((choice = enterChoice()) != 5) {
switch (choice) {
case 1:
textFile(cfPtr);
break;
case 2:
updateRecord(cfPtr);
break;
case 3:
newRecord(cfPtr);
break;
case 4:
deleteRecord(cfPtr);
break;
default:
puts("Incorrect choice");
break;
}
}
fclose(cfPtr);
}
}
void textFile(FILE* readPtr) {
FILE* writePtr;
if ((writePtr = fopen("accounts.txt", "w")) == NULL) {
puts("File could not be opened.");
}
else {
rewind(readPtr);
fprintf(writePtr, "%-6s%-16s%-11s%10s\n", "Acct", "Last Name", "First Name",
"Balance");
while (!feof(readPtr)) {
struct clientData client = { 0, "", "", 0.0 };
int result = fread(&client, sizeof(struct clientData), 1, readPtr);
if (result != 0 && client.acctNum != 0) {
fprintf(writePtr, "%-6d%-16s%-11s%10.2f\n", client.acctNum,
client.lastName, client.firstName, client.balance);
}
}
fclose(writePtr);
}
}
void updateRecord(FILE* fPtr) {
printf("%s", "Enter account to update (1 - 100): ");
unsigned int account;
scanf("%d", &account);
fseek(fPtr, (account - 1) * sizeof(struct clientData), SEEK_SET);
struct clientData client = { 0, "", "", 0.0 };
fread(&client, sizeof(struct clientData), 1, fPtr);
if (client.acctNum == 0) {
printf("Account #%d has no information.\n", account);
}
else {
printf("%-6d%-16s%-11s%10.2f\n\n", client.acctNum, client.lastName,
client.firstName, client.balance);
=
printf("%s", "Enter charge (+) or payment (-): ");
double transaction;
scanf("%lf", &transaction);
client.balance += transaction;
printf("%-6d%-16s%-11s%10.2f\n", client.acctNum, client.lastName,
client.firstName, client.balance);
fseek(fPtr, (account - 1) * sizeof(struct clientData), SEEK_SET);
fwrite(&client, sizeof(struct clientData), 1, fPtr);
}
}
void deleteRecord(FILE* fPtr) {
printf("%s", "Enter account number to delete (1 - 100): ");
unsigned int accountNum;
scanf("%d", &accountNum);
fseek(fPtr, (accountNum - 1) * sizeof(struct clientData), SEEK_SET);
struct clientData client;
fread(&client, sizeof(struct clientData), 1, fPtr);
if (client.acctNum == 0) {
printf("Account %d does not exist.\n", accountNum);
}
else {
fseek(fPtr, (accountNum - 1) * sizeof(struct clientData), SEEK_SET);
struct clientData blankClient = { 0, "", "", 0 };
fwrite(&blankClient, sizeof(struct clientData), 1, fPtr);
}
}
void newRecord(FILE* fPtr) {
printf("%s", "Enter new account number (1 - 100): ");
unsigned int accountNum;
scanf("%d", &accountNum);
fseek(fPtr, (accountNum - 1) * sizeof(struct clientData), SEEK_SET);
struct clientData client = { 0, "", "", 0.0 };
fread(&client, sizeof(struct clientData), 1, fPtr);
if (client.acctNum != 0) {
printf("Account #%d already contains information.\n? ", client.acctNum);
scanf("%14s%9s%lf", &client.lastName, &client.firstName, &client.balance);
client.acctNum = accountNum;
fseek(fPtr, (client.acctNum - 1) * sizeof(struct clientData), SEEK_SET);
fwrite(&client, sizeof(struct clientData), 1, fPtr);
}
}
unsigned int enterChoice(void) {
printf("%s", "\nEnter your choice\n"
"1 - store a formatted text file of accounts called\n"
" \"accounts.txt\" for printing\n"
"2 - update an account\n"
"3 - add a new account\n"
"4 - delete an account\n"
"5 - end program\n? ");
unsigned int menuChoice;
scanf("%u", &menuChoice);
return menuChoice;
}
Can someone explain this to me. This is C
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