OS-(II) Assignment 2: Slot 1- 1)

A bit vector (array) of size n which is initialized randomly to 0 or 1.
A menu with the options
- Show Bit Vector
- Create New File
- Show Directory
- Delete File
- Exit

I) Write a program to simulate Sequential (Contiguous) file allocation method. Assume disk with n number of blocks. Give value of n as input. Write menu driver program with menu options as mentioned above and implement each option.

Solution:

#include <stdio.h>

#include <string.h>

#include <conio.h> 

#include <malloc.h>

struct dir

{

char filename[20];

int start;

int len;

struct dir *next;

};

struct dir *d,*newNode,*lastNode,*temp;

int Bit[100],n;

void Generate_BitVector()

{

int i,num;

for(i=0;i<=n;i++)

    {  

    num=rand();

    Bit[i]=num%2;

    }

}

void Show_BitVector()

{

int i;

printf("\nGiven Bit Array is\n");

for(i=0;i<=n;i++)

    {   

printf(" %d ",Bit[i]);   

    }

}

void ShowDirectory()

{

printf("\nFilename\tStart\tLength\n");

temp=d;

while(temp)

{

     printf("%s\t\t%d\t%d\n",temp->filename,temp->start,temp->len);

    temp=temp->next;

}

}

void CreateFile()

{

char filename[20];

int i,l,j,k,n1,start,flag;;

printf("\nEnter The File Name\n");

scanf("%s",filename);

printf("\nEnter The Length of File\n");

scanf("%d",&l);

for(i=0;i<=n;i++)

        {

    if(Bit[i]==1)

    {

    start=i;

    flag=1;

    k=i;

    for(j=0;j<l;j++)

    {

    if(Bit[k]==0)

    {

    flag=0;

    start=-1;

break;

}

k++;

}

}

if(flag==1)

{

break;

}

}

if(start>=0)

{

i=start;

n1=0;

while(n1<l)

{

Bit[i]=0;

i++;

n1++;

}

Show_BitVector();

    newNode=(struct dir *)malloc(sizeof(struct dir));

strcpy(newNode->filename,filename);

newNode->len=l;

newNode->start=start;

if(d==NULL)

{

lastNode=d=newNode;

}

else

{

lastNode->next=newNode;

lastNode=lastNode->next;

}

printf("\nFile Allocation is Successfull\n");

}

else

printf("\nFile Allocation Failed\n");

}

void DeleteFile()

{

struct dir *temp1;

int start, len,i,j;

char filename[20];

printf("\nEnter The Filename to delete");

scanf("%s",filename);

temp=d;

if(d==NULL)

{

printf("\nError...!Directory Is Empty\n");

}

else

{

if(strcmp(temp->filename,filename))

{

temp1=temp->next;

d=temp1;

temp=NULL;

}

else

{

while(temp)

{

if(strcmp(temp->next->filename,filename))

break;

temp=temp->next;

}

temp1=temp->next;

}

}

start=temp1->start;

len=temp1->len;

i=start;

j=0;

while(j<len)

{

Bit[i]=1;

i++;

j++;

}

Show_BitVector();

if(temp!=NULL)

{

temp->next=temp1->next;

temp1->next=NULL;

free(temp1);

}

}

int main()

{

    int Bit[100],i,j,k,start,flag,ch;

    d=NULL;

    printf("\nEnter The Number Of Blocks!\n");

    scanf("%d",&n);

    Generate_BitVector();

    do 

    { 

        printf("\n\n--------MENU------------"); 

     printf("\n\n1.ShowBitVector:\n2.Create New File:\n3.Show Directory\n4.Delete File\n5.exit:"); 

        printf("\n\n Enter your choice:"); 

        scanf("%d",&ch); 

        switch(ch) 

        { 

            case 1: Show_BitVector();

                break; 

            case 2: CreateFile(d); 

                break;

    case 3: ShowDirectory(d);

break;

    case 4: DeleteFile();

    break;

    } 

    }while(ch!=5);

    return 0;

}