I need to 1.) allow to users to store all entries into a location/filename specified by user (or default location) and 2.) retrieve entries from said location.
At the moment I can't retrieve files (pRead keeps coming up NULL). I think pWrite is saving the data to file, but b/c I can't retrieve the file I can't be sure of that. I think the issue is with letting the user specify the name of the File, but obviously I'm not sure. My compiler isn't showing any errors, but is there something wrong with my syntax or something? I'm hoping someone can help me narrow down the problem.
Here are my functions:
Here's my entire program for reference.Code://Store entries in file void StoreFile() { int iPick; char FileName[50]; int i; printf("\n1) Name the file yourself or\n2) Use the default name(phone_book.txt)\n\nSelect your option (enter 1 or 2): "); scanf("%d", &iPick); if (iPick == 2) { pWrite = fopen("phone_book.txt", "w"); } else { printf("What do you want to name the file?"); scanf("%s", FileName); pWrite = fopen("FileName", "w"); } if (pWrite == NULL) { printf("\nFile cannot be opened\n"); } else { for (i = 0; i < count; i++) { fprintf(pWrite, "%s\t%s\t%s\n", lt[i].FirstName, lt[i].LastName, lt[i].PhoneNumber); fclose(pWrite); }//End for loop printf("\nEntries saved to file\n"); } }//End Function //Retrieve entries from file void RetrieveFile() { char rFileName[50]; int i; printf("\nName of file you want to retrieve? "); scanf("%s", rFileName); pRead = fopen("rFileName", "r"); if (pRead == NULL) { printf("\nFile cannot be opened\n"); } else { for (i = 0; i < count; i++) { fscanf(pWrite, "%s\t%s\t%s\n", lt[i].FirstName, lt[i].LastName, lt[i].PhoneNumber); printf("\n%s\t%s\t%s", lt[i].FirstName, lt[i].LastName, lt[i].PhoneNumber); }//End for loop } }//End Function
Code:#include <stdio.h> #include <stdlib.h> #include <string.h> #include <time.h> //Function prototypes void Add(); void Delete(); void Display(); void Alphabetical(); void Number(); void Random(); void DeleteAll(); void StoreFile(); void RetrieveFile(); //Structure for Phonebook list typedef struct PhoneBookList { char *FirstName; char *LastName; char *PhoneNumber; } list; //Structure for delete typedef struct DeleteEntry { char *FirstName; char *LastName; } take; //Pointers to structures list *lt; take *tk; //Global variables int count = 0; int delCount = 0; //Files FILE *pWrite; FILE *pRead; int main(void) { //Variable declarations int iSelection; do { //Print menu to screen, ask user for selection printf("\n\nPhone Book:\n\n"); printf("1) Add friend\n"); printf("2) Delete friend\n"); printf("3) Display phone book\n"); printf("4) Sort and display entries alphabetically by last name\n"); printf("5) Find phone number for given name\n"); printf("6) Randomly select contact\n"); printf("7) Delete all contacts\n"); printf("8) Store all entries in a file\n"); printf("9) Retrieve entries from file\n"); printf("10) Exit\n"); printf("What do you want to do? "); scanf("%d", &iSelection); switch (iSelection) { case 1: //Add entry Add(); break; case 2: //Delete entry Delete(); break; case 3: //Display all entries Display(); break; case 4: //Sort entries alphabetically Alphabetical(); break; case 5: //Find phone number Number(); break; case 6: //Randomly select contact Random(); break; case 7: //Delete all contacts DeleteAll(); break; case 8: //Store entries in a file StoreFile(); break; case 9: //Retrieve entries from file RetrieveFile(); break; case 10: //Break loop and close program break; default: //User entered an invalid number printf("\nYou entered an invalid selection. Try again.\n"); break; } //End Switch } while (iSelection != 10); //End Do While loop //Return used memory free(tk); free(lt); tk = NULL; lt = NULL; return 0; } //End Main //Function definitions //Add an entry void Add() { char *leftName; if (count == 0) { lt = (list *) malloc ((count*25) + 25); } else { lt = (list *) realloc (lt, (count*50) + 50); } if (lt == NULL) { printf("You cannot add more memory\n"); } else { lt[count].FirstName = (char *) malloc(sizeof(char)*15); lt[count].LastName = (char *) malloc(sizeof(char)*15); lt[count].PhoneNumber = (char *) malloc(sizeof(char)*15); printf("\nEnter their First Name: "); scanf("%s", lt[count].FirstName); printf("\nEnter their Last Name: "); scanf("%s", lt[count].LastName); printf("\nEnter their Phone Number: "); scanf("%s", lt[count].PhoneNumber); printf("\nContact added\n"); } count++; }//End Function //Delete an entry void Delete() { int i; int q = 0; char *userName; if (delCount == 0) { tk = (take *) malloc ((delCount*25) + 25); } else { tk = (take *) realloc (tk, (delCount*1) + 1); } if (tk == NULL) { printf("This cannot be deleted (out of memory)\n"); } else { tk[delCount].FirstName = (char *) malloc(sizeof(char)*15); tk[delCount].LastName = (char *) malloc(sizeof(char)*15); printf("\nEnter their First Name: "); scanf("%s", tk[delCount].FirstName); printf("\nEnter their Last Name: "); scanf("%s", tk[delCount].LastName); } for (i = 0; i < count; i++) { if (lt[i].FirstName == NULL && lt[i].LastName == NULL) continue; if (strcmp(lt[i].FirstName, tk[delCount].FirstName) == 0 && strcmp(lt[i].LastName, tk[delCount].LastName) == 0) { printf("\n%s %s has been deleted\n", lt[i].FirstName, lt[i].LastName); lt[i].FirstName = NULL; lt[i].LastName = NULL; lt[i].PhoneNumber = NULL; q = 1; break; } } //End for loop if (q != 1) { printf("\nThis person is not in the Phonebook\n"); } delCount++; count--; }//End function //Display all phonebook entries void Display() { int i; printf("\nYour contacts:\n"); for (i = 0; i < count; i++) { if (lt[i].FirstName != NULL && lt[i].LastName != NULL) { printf("\n%s %s: %s\n", lt[i].FirstName, lt[i].LastName, lt[i].PhoneNumber); } }//End for loop system("pause"); }//End function //Sort entries alphabetically by last name. void Alphabetical() { int i; int j; char temp[50][50]; printf("\nYour contacts:\n"); for (i = 0; i < count; i++) { for (j = i + 1; j < count; j++) { if (strcmp(lt[i].LastName, lt[j].LastName) > 0) { strcpy(temp[i], lt[i].LastName); strcpy(lt[i].LastName, lt[j].LastName); strcpy(lt[j].LastName, temp[i]); } } }//End for loop for (i = 0; i < count; i++) printf("\n%s\n", lt[i].LastName); system("pause"); }//End function //Find phone number for given name void Number() { int i; int q = 0; char fName[25]; char lName[25]; printf("\nEnter their First Name: "); scanf("%s", fName); printf("\nEnter their Last Name: "); scanf("%s", lName); for (i = 0; i < count; i++) { if (strcmp(lt[i].FirstName, fName) == 0 && strcmp(lt[i].LastName, lName) == 0) { printf("\n%s %s's phone number is: %s\n", lt[i].FirstName, lt[i].LastName, lt[i].PhoneNumber); q = 1; break; } } if (q != 1) { printf("\nThis person is not in the Phonebook\n"); } system("pause"); }//End function //Randomly select contact void Random() { srand(time(NULL)); int iRandomNum; iRandomNum = (rand() % count) + 1; printf("%s %s: %s\n", lt[iRandomNum].FirstName, lt[iRandomNum].LastName, lt[iRandomNum].PhoneNumber); system("pause"); }//End function //Delete everyone from phone book void DeleteAll() { int i; for (i = 0; i < count; i++) { do{ lt[i].FirstName = NULL; lt[i].LastName = NULL; lt[i].PhoneNumber = NULL; break; } while (i <= count); } printf("\nAll contacts deleted\n\n"); system("pause"); }//End function //Store entries in file void StoreFile() { int iPick; char FileName[50]; int i; printf("\n1) Name the file yourself or\n2) Use the default name(phone_book.txt)\n\nSelect your option (enter 1 or 2): "); scanf("%d", &iPick); if (iPick == 2) { pWrite = fopen("phone_book.txt", "w"); } else { printf("What do you want to name the file?"); scanf("%s", FileName); pWrite = fopen("FileName", "w"); } if (pWrite == NULL) { printf("\nFile cannot be opened\n"); } else { for (i = 0; i < count; i++) { fprintf(pWrite, "%s\t%s\t%s\n", lt[i].FirstName, lt[i].LastName, lt[i].PhoneNumber); fclose(pWrite); }//End for loop printf("\nEntries saved to file\n"); } }//End Function //Retrieve entries from file void RetrieveFile() { char rFileName[50]; int i; printf("\nName of file you want to retrieve? "); scanf("%s", rFileName); pRead = fopen("rFileName", "r"); if (pRead == NULL) { printf("\nFile cannot be opened\n"); } else { for (i = 0; i < count; i++) { fscanf(pWrite, "%s\t%s\t%s\n", lt[i].FirstName, lt[i].LastName, lt[i].PhoneNumber); printf("\n%s\t%s\t%s", lt[i].FirstName, lt[i].LastName, lt[i].PhoneNumber); }//End for loop } }//End Function
