Hello
I am having trouble with my project crashing for every case. We are told to read in a data text file and store into structs and create a linked list of data and allow a user to choose from 4 menu options. I am completely new to linked lists and am having a hard time understanding how to string compare user entered names and find them amongs the text file given.
If anyone could give some aid or help as to what I am doing incorrect or why it is crashing, it would be much appreciated. There are no compiler errors so i am completely at a standstill of what to do
#include <stdio.h>
#include <stdlib.h>
#define Max 100
struct account {
char *firstname;
char *lastname;
int *digits;
} ;
struct node {
char *firstname;
char *lastname;
int *digits;
struct account emp;
struct node* Pnext;
struct node* Pprev;
};
int count=0;
struct node* Phead;
struct node* Ptail;
struct node* create(struct account emp);
struct node*add(struct account emp);
struct node*searchbyfirstname (char *firstname);
struct node*searchbylastname (char *lastname);
void main(void)
{
FILE *infile= NULL;
FILE *outfile= NULL;
int choice=4, i, *digits, x;
char *infilename, *outfilename, *firstname, *lastname;
struct account emp;
struct node*ppt;
struct node*ptr;
struct node*account;
struct node*z;
struct node* create(struct account emp);
struct node*add(struct account emp);
struct node*searchbyfirstname (char *firstname);
struct node*searchbylastname (char *lastname);
infilename=(char *)malloc(Max* sizeof(char ));
outfilename=(char *)malloc(Max* sizeof(char ));
firstname=(char *)malloc(Max* sizeof(char ));
lastname=(char *)malloc(Max* sizeof(char ));
digits=(int *)malloc(Max* sizeof(int ));
do
{
printf("Input filename:");
scanf("%s",infilename);
if((infile = fopen(infilename, "r")) == NULL)
{
printf("ERROR: file %s can not be opened!\n",infilename);
}
}while(infile == NULL);
for(i=0 ; *(infilename + i) != '.'; i++)
{
*(outfilename + i) = *(infilename + i);
}
*(outfilename + i) = '\0';
strcat(outfilename, "_out.txt");
if((outfile = fopen(outfilename, "w")) == NULL){
{
printf("ERROR: file %s can not be opened!\n",outfilename);
}
}while(outfile == NULL);
while(fscanf(infile, "%s\t%s/t%s", &firstname, &lastname, &digits)!=EOF)
{
fscanf(infile, "%s\t%s\t%s", &firstname, &lastname, &digits);
}
while(choice!=0)
{
printf("\nA Program to Calculate\n\nWould you like to Add, Subtract, or Divide?\n\n");
printf("(0) Write output file and exit \n");
printf("(1) Print the phone book\n");
printf("(2) Add new account at head of the phone book\n");
printf("(3) Find by last name\n");
printf("(4) Find by first name\n\n");
scanf("%d", &choice);
switch(choice)
{
case 0: while(digits != NULL)
{
fprintf(outfile, "%s %s %s", &firstname, &lastname, &digits);
}
break;
case 1:
while(digits == NULL)
{
printf("%s %s %s", &firstname, &lastname, &digits);
}
break;
case 2:
printf("Enter the First name");
scanf("%s", &firstname);
printf("Enter the Last name");
scanf("%s", &lastname);
printf("Enter the phone number");
scanf("%s", &digits);
ptr= create (emp);
struct node* ptr;
ptr = (struct node*)malloc(sizeof(struct node));
strcpy(ptr->firstname,firstname);
ptr->lastname=lastname;
ptr->digits=digits;
ptr->Pnext= account emp;
break;
case 3:
printf("Type the first name of the account");
scanf("%s", emp.firstname);
ppt=searchbyfirstname(emp.firstname);
if(ppt==NULL)
{
printf("Name is not found");
}
else
{
printf("account last name is : %s", ppt->emp.lastname);
printf("account number is %ld", ppt->emp.digits);
}
break;
case 4:
printf("Type the last name of the account");
scanf("%s", emp.lastname);
ppt=searchbylastname(emp.lastname);
if(ppt==NULL)
{
printf("Name is not found");
}
else
{
printf("account first name is : %s", ppt->emp.firstname);
printf("account number is %ld", ppt->emp.digits);
}
break;
}
}
}
/*create a node*/
struct node* create(struct account emp)
{
struct node*ptr;
ptr=(struct node*)malloc(sizeof(struct node));
if (ptr)
{
ptr->emp=emp;
ptr->Pprev=NULL;
ptr->Pnext=NULL;
}
return(ptr);
}
struct node*searchbyfirstname (char *firstname)
{
struct node*ptr;
struct node*Pmid;
int i;
int mid;
int low;
int high;
ptr=NULL;
low=0;
high=count+1;
while((low<=high))
{
mid=(low+high)/2;
Pmid=Phead;
for(i=0;i<mid;i++)
{
Pmid=Pmid->Pnext;
}
if(strcmp(Pmid->emp.firstname,firstname)==0)
{
ptr=Pmid;
break;
}
else
{
if(strcmp(Pmid->emp.firstname,firstname)>0)
{
high=mid-1;
}
else
{
if(strcmp(Pmid->emp.firstname,firstname)<0)
{
low=mid+1;
}
}
}
}
return ptr;
}
struct node*searchbylastname (char *lastname)
{
struct node*ptr;
struct node*Pmid;
int i;
int mid;
int low;
int high;
ptr=NULL;
low=0;
high=count+1;
while((low<=high))
{
mid=(low+high)/2;
Pmid=Phead;
for(i=0;i<mid;i++)
{
Pmid=Pmid->Pnext;
}
if(strcmp(Pmid->emp.lastname,lastname)==0)
{
ptr=Pmid;
break;
}
else
{
if(strcmp(Pmid->emp.lastname,lastname)>0)
{
high=mid-1;
}
else
{
if(strcmp(Pmid->emp.lastname,lastname)<0)
{
low=mid+1;
}
}
}
}
return ptr;
}
