int writeToDisk(int fileDisId,char *buffer,int length)

#include <sys/types.h>
#include <unistd.h>
#include <sys/fcntl.h>
#include <cstdio>
#include <iostream>
#include <string>

#define DISK_NAME "/dev/loop0"

using namespace std;


/**
Initialize the Virtual Disk File
*/
int initDisk()
{
    int fd=open(DISK_NAME, O_RDWR);

    if(fd < 0)
    {
        perror("Couldn't open device");
        return 1;
    }
    return fd;
}


/**
Read a set of Blocks into the Buffer
*/
int readFromDisk(int fileDisId,char *buffer,int length)
{
    ssize_t readBytes;
    readBytes=read(fileDisId, buffer, length);
    close(fileDisId);
    return (int)readBytes;
}

/**
Write the Buffer Content to HDD Blocks
*/
int writeToDisk(int fileDisId,char *buffer,int length)
{
    ssize_t writeBytes;
    writeBytes=write(fileDisId,buffer,length);
    close(fileDisId);
    return (int)writeBytes;
}

/**
Seek out a Particular Block In the Disk
Block_SIZE=512bytes
*/
int seekDisk(int fileDisId)
{
    cout<<"Seeking the File Disk..."<<endl;

    if(lseek(fileDisId, 0L, SEEK_SET) != 0L)
    {
        perror("Couldn't seek");
        close(fileDisId);
        return(1);
    }
    close(fileDisId);
    return 0;
}



int main(void)
{

    cout<<"\n"<<"Running the OS File Manager....Main"<<endl;

    /*
    Test The File Manager
    */

    int diskId;


    char buffer[1024];
     diskId = initDisk();
    cout<<"No of Bytes Read : "<<readFromDisk(diskId,buffer,1024)<<endl;

     diskId = initDisk();
     seekDisk(diskId);

    diskId = initDisk();
    cout<<"No of Bytes Written : "<<writeToDisk(diskId,buffer,1024)<<endl;

    return 0;
}

int writeToDisk(int fileDisId,char *buffer,int length)