#include<iostream.h>
#include<conio.h>
#include<stdio.h>
#include<dos.h>
#include<sys/stat.h>
#include<alloc.h>
#include<stdlib.h>
typedef struct used
{
int inode;
struct stat temp;
struct used *next;
struct time create;
struct time modi;
int lock;
int ref;
};
used *getnode()
{ used *t=(used *)malloc(sizeof(used));
t->next=NULL;
t->ref=1;
struct time temptime;
gettime(&temptime);
t->create=temptime;
return t;
}
used *fre,*start;
void init(int number)
{
used *t1,*t2,*t3;
// capacity of the inode list is 10
int i,j,k,l;
fre=getnode();
start=NULL;
t2=fre;
for(i=0;i<number;i++)
{ t1=getnode();
t2->next=t1;
t2=t1;
}
}
// max inode number will be 1000
used *cache;
void usenode();
void copy_in(used *);
void input(used *);
void display();
char loop();
void close();
int search(used *);
void incref(used *);
void main()
{
clrscr();
init(19);
char c;
int j=0;
while(1)
{ c=loop();
j=0;
if(c==13)
{ input(cache);
if(search(cache))
incref(cache);
else
usenode();
}
if(c==27)
close();
}
display();
getch();
}
char loop()
{
while(!kbhit())
{ display();
delay(1000);
clrscr();
}
char c=getch();
return c;
}
void usenode()
{
used *t,*temp;
t=fre;
if(t->next==NULL)
{
printf("No fre node avail.\n");
return ;
}
while(t->next!=NULL)
{ temp=t;
t=t->next;
}
temp->next=NULL;
// one node is deleted
t=start;
if(start==NULL)
{
start=getnode();
copy_in(start);
return ;
}
while(t->next!=NULL)
{
t=t->next;
}
temp=getnode();
copy_in(temp);
t->next=temp;
return ;
}
void copy_in(used *temp)
{
temp->inode=cache->inode;
}
void display()
{
used *t;
t=start;
int i=0;
// displaying used incore inodes
while(t!=NULL)
{ gotoxy(10,4+i);
cout<<t->inode<<":"<<t->ref;
printf(" Created on : %2d:%02d:%02d",t->create.ti_hour,t->create.ti_min,t->create.ti_sec);
t=t->next;
i++;
}
cout<<"\nUsed incore copies : "<<i<<"\n\n\n";
i=0;
// displaying fre inode list
t=fre;
while(t!=NULL)
{ t=t->next;
i++;
}
cout<<"Free incore copies : "<<i<<"\n\n\n";
}
void input(used *ch)
{ // clrscr();
int i,j,k;
cout<<"inode number : ";
cin>>ch->inode;
cout<<"\nEnter permission : ";
cin>>i;
ch->lock=i;
}
void close()
{
cout<<"Enter inode for closing file : ";
int i;
cin>>i;
used *t,*pred,*succ;
t=start;
pred=t;
int flag=0;
if(t->inode==i)
{
flag=1;
}
while(t!=NULL && t->inode!=i)
{ pred=t;
t=t->next;
if(t->inode==i)
{ flag=1;
break;
}
}
if(flag==0)
{ printf("No such found..\n");
return ;
}
if(t->ref>=1)
{ t->ref--;
}
if(t->ref!=0)
return ;
if(pred==t)
{ if(start->next!=NULL)
start=start->next;
else
start=NULL;
}
else
{
pred->next=t->next;
t->next=NULL;
}
// increments free inode list
t=fre;
while(t->next!=NULL)
{ t=t->next;
}
succ=getnode();
t->next=succ;
}
int search(used *ch)
{
used *t;
t=start;
if(t==NULL)
return 0;
int flag=0;
while(t!=NULL)
{ if(t->inode == ch->inode)
{ flag=1;
return flag;
}
t=t->next;
}
return flag;
}
void incref(used *ch)
{
used *t;
t=start;
int flag=0;
while(t!=NULL)
{ if(t->inode == ch->inode)
{ t->ref++;
break;
}
t=t->next;
}
}
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