struct address {
char name[30] ;
char street[30] ;
char city[20] ;
char code[4] ;
char Tel[10] ;
struct address *next ;
struct address *prior ;
} list_entry ;

struct address *start ;
struct address *last ;

void enter() , display() , search() ;
void save() , load() , list() , del();
void display(struct address *info, int *row);

struct address *find(char *);
int menu_select();
struct address *store(struct address *, struct
address *);

int main ()
{
start = last = NULL ;
for(;;) {
switch(menu_select()) {
case 1: enter(); break ;
case 2 : del(); break ;
case 3: list() ;
break ;
case 4: search(); break ;
case 5: save(); break ;
case 6: load(); break ;
case 7: exit(0) ;
}//end of switch
}//end of for
}//end of main
//****************
int menu_select()
{
char s[5];
clrscr() ;
gotoxy(25, 4) ;
cout << “1. enter a name ” ;
gotoxy(25, 6) ;
cout << “2. delete a name ” ;
gotoxy(25, 8) ;
cout << “3. list all files ” ;
gotoxy(25, 10) ;
cout << “4. search “;
gotoxy(25, 12) ;
cout << “5. save the file “;
gotoxy(25, 14) ;
cout << “6. load the file “;
gotoxy(25, 16) ;
cout << “7. quit ” ;
do {
gotoxy(20, 18) ;
cout<<“enter your select-(1-7):”;
gets(s);
} while (atoi(s) < 0 || atoi(s) > 7) ;
return atoi(s) ;
}
//*********************
void enter ()
{
struct address *info ;
int i ;
char ch ;
clrscr() ;
gotoxy(3, 2) ;
cout << ” name street city
code Tel”;
gotoxy(3, 3) ;
cout << ” ———— ——– “;
cout << “——– —– ——- “;
i = 4 ;
for (;;) {
info = (struct address *)malloc(sizeof
(list_entry)) ;
if(!info) {
cout << “\n out of memory. press a key ”
;
getch();
return ;
}
gotoxy(3, i) ;
gets(info -> name) ;
if (!info -> name[0]) {
gotoxy(15, i + 1) ;
cout << “press a key to continue”;
getch() ;
break ;
}//end of if
gotoxy(18, i);
gets(info -> street) ;
gotoxy(28, i) ;
gets(info -> city) ;
gotoxy(38, i) ;
gets(info -> code) ;
gotoxy(45, i) ;
gets(info -> Tel) ;
i++ ;
start = store(info, start) ;
} /* entry loop */
}
//**************
struct address *store(struct address *i, struct
address *top)
{
struct address *old, *p ;
if(last == NULL) {
i -> next = NULL ;
i -> prior = NULL ;
start = i;
last = i ;
return i ;
}
p = top ;
old = NULL ;
while (p != NULL) {
if(strcmp(p -> name, i -> name) < 0) {
old = p ;
p = p -> next ;
}//end of if
else {
if (p -> prior) {
p -> prior -> next=i ;
i -> next=p ;
i -> prior=p -> prior;
p -> prior=i ;
return top ;
}//end of if
i -> next = p ;
i -> prior = NULL ;
p -> prior = i ;
return i ;
}//end of if
} // end of while
old -> next = i ;
i -> next = NULL ;
i -> prior = old ;
last = i ;
return start ;
}
//******************
void del()
{
struct address *info;
char name[80];
gotoxy(20, 20) ;
cout << ” enter name for delete : “;
gets(name) ;
info = find(name) ;
if(info == NULL) {
gotoxy(10, 20) ;
cout << ” name not found! press a key to
continue.”;
getch() ;
}
if (info)
if (start == info)
{
start = info -> next ;
if(start)
start -> prior = NULL ;
else
last = NULL ;
} //end of if
else {
info -> prior -> next = info -> next;
if(info != last)
info -> next -> prior = info ->
prior;
else
last = info -> prior ;
} //end of else
free(info) ;
gotoxy(10,20) ;
cout << “name deleted, press a key to
continue.”;
getch() ;
}