Reading a text file to a doubly linked list - c

Question

I'm coding a contact manager using a doubly linked list that is manipulated by functions using pointers that reads in a contactList.txt.
#include<stdio.h>
#include<conio.h>
#include<string.h>
#include<process.h>
#include<stdlib.h>
#include<dos.h>
//functions
listelement * getFirst(listelement *listpointer,string query[MAX]);
void getLast();
void getEmail();
void getCompany();
void getNumber();
void editCon();
void delCon();
void addCon();
void listAll();
void sortCon();
void Menu (int *choice);
#define MAX 20
//struct to order contactList
struct contact
{
string firstName[MAX],lastName[MAX],email[MAX],companyName[MAX];
long phoneNum[MAX];
struct listelement *link
struct contact *next;
struct contact *prev;
}list;
int main()
{
listelement listmember, *listpointer;
string query;int iChoice = 0;
listpointer = NULL;
Menu (&iChoice);
int iChoice;
fflush(stdin);
scanf_s("%d", &iChoice);
// user enters one of 9 values
// options are as follows: get first name,last name,list all contacts,search through contacts,add a new contact,edit/delete or sort contacts.
switch(iChoice)
{
case 1:
{
printf ("Enter contact first name to get details ");
scanf ("%d", &query);
listpointer = getFirst (listpointer, query);
break;
}
case 2:
{
getLast();
break;
}
case 3:
{
listAll();
break;
}
case 4:
{
getEmail();
break;
}
case 5:
{
getCompany();
break;
}
case 6:
{
getNumber();
break;
}
case 7:
{
addCon();
break;
}
case 8:
{
editCon();
break;
}
case 9:
{
delCon();
break;
}
case 10:
{
sortCon();
break;
}
case 11: // exit
{
printf("\n\nProgram exiting!...");
exit(0);//terminates program
break;
}
default:
printf ("Invalid menu choice - try again\n");
break;
}//end of switch
return(iChoice);
}//end of main
//menu function to test if invalid input was entered in a menu choice.
void Menu (int *iChoice)
{
char local;
system("cls");
printf("\n\n\t\\n\n");
printf("\n\n\t\tWelcome to my Contact Manager\n\n");
printf("\n\t\t1. First name");
printf("\n\t\t2. Last name");
printf("\n\t\t3. List all contacts");
printf("\n\t\t4. Search email");
printf("\n\t\t5. Search company name");
printf("\n\t\t6. Search number");
printf("\n\t\t7. Add contact");
printf("\n\t\t8. Edit contact");
printf("\n\t\t9. Delete contact");
printf("\n\t\t10. Sort contacts");
printf("\n\t\t11. Exit");
printf("\n\n\t\tEnter your menu choice: ");
do
{
local = getchar ();
if ( (isdigit(local) == FALSE) && (local != '\n') )
{
printf ("\nYou must enter an integer.\n");
printf ("");
}
} while (isdigit ((unsigned char) local) == FALSE);
*iChoice = (int) local - '0';
}
//function to get a contact by entering first name
listelement * getFirst (listelement *listpointer, string query)
{
//variables
char query[MAX],firstName[MAX];
FILE *fp, *ft;
int i,n,ch,l,found;
system("cls");
do
{
found=0;
l=strlen(query);
fp=fopen("ContactList.txt","r");
system("cls");
printf("\n\n..::Search result for '%s' \n===================================================\n",query);
while(fread(&list,sizeof(list),1,fp)==1)
{
for(i=0;i<=l;i++)
firstName[i]=list.firstName[i];
firstName[l]='\0';
if(stricmp(firstName,query)==0)
{
printf("\n..::First Name\t: %s\n..::Second Name\t: %ld\n..::Email\t: %s\n..::CompanyName\t: %s\n..::Number\t: %s\n",list.firstName,list.lastName,list.email,list.companyName.list.phoneNumber);
found++;
if (found%4==0)
{
printf("..::Press any key to continue...");
getch();
}
}
}
if(found==0)
printf("\n..::No match found!");
else
printf("\n..::%d match(s) found!",found);
fclose(fp);
printf("\n ..::Try again?\n\n\t[1] Yes\t\t[11] No\n\t");
scanf("%d",&ch);
}while(ch==1);
}
Anyone have any idea as to where I'm going wrong in the code?Thanks

Answer 1

Your errors are because:
1) you don't define listelement anywhere
2) you don't define string anywhere (and it's not a type in C)
3) You need to move the #define MAX up above before you use it.
4) You don't define FALSE anywhere (and it's not a type in C)
5) You're redefining elements too, in getFirst() you've passed in query as a "string", then you
define a new query as a char array
6) You get redefinition errors because you've got more than one define. That's somewhat #5 but there's more as well. In your main you declare iChoice here: string query;int iChoice = 0;
then you declare it again int iChoice; right after your Menu() call
7) Please don't do fflush(stdin) that's undefined behavior as per the C standard