is c++ alright for writing vhd files

[flyhigh]

i have visual studio 6.0 if i buy c++ will it run with this and is there lots of people using it like vb6?
thanks

[akhileshbc]

VS6.0 is a suite that contains several language in series like, VB6, VC++6, VF6, etc... Why do you need to buy it separate ?

If you are moving to .Net, then try Visual Studio 2010. Or get the free Express versions of the languages from Microsoft's site.

Or, if you are a student, you might get the free Pro versions of these languages via DreamSpark initiative of Microsoft.

[szlamany]

I believe the OP wants to work with VHD files (virtual hard drives).

[akhileshbc]

I believe the OP wants to work with VHD files (virtual hard drives).

oops sorry !

[flyhigh]

never paid attention to the others time to start

[flyhigh]

ive been googling alot on how to make /create an vhd file ,what exactly do i look under to find more info?
thanks

[szlamany]

Just curious - you aren't trying to break into a VHD file - are you?

[flyhigh]

nope.
just strickly making one my self,i know theres tons of programs out there to do this ,i have some of them,just something i do to learn how it works and i like to do it myself , at least as much as i can...

[szlamany]

I searched up

VHD FILE FORMAT

This looks like a good link - with more links at the bottom

http://www.enotes.com/topic/VHD_(file_format)

[flyhigh]

hey msdn says the api for Virtual Hard Disk have to be running win 7 can it still be used in win xp?

[flyhigh]

hi
what does (cin) stand for?
how do i put my name and age in without having to prompt the user?
thanks

  // prompt user to enter the new info  
  cout << "Set database info...\n";
  cout << "Name: ";
  cin.getline(per.name, 8);
  
  cout << "Age: ";
  (cin >> per.age).get();// add the .get() to clear the newline character
  
  cout << "Salary: ";
  (cin >> per.salary).get();// note .getline() clears its own newline character

  // save the new user-entered data  
  if (SaveDB(&per))
    cout << "\nDatabase saved!\n";
  else
    cout << "\nUnable to save database!\n";

  // give the user a chance to look things over before quitting
  cout << "\n[hit enter]";  
  cin.get();

  // return 0 on success (main() should never be void!)
  return 0;

[akhileshbc]

cin is for input operations(to read user inputs) and cout is for output operations(displaying on the screen)

[flyhigh]

do i have to use (char) letters and (int) for numbers?


 
// the data that will go into the database
struct Person {
  char name[40];
  int age;
  float salary;
};

[akhileshbc]

char is the datatype for storing character. Inorder to store a string, you would use an array of characters(a string would contain a number of characters. So we are using array of char to store strings)

And int is to hold numbers within a specific range. It's of the range -32K to +32K I think. So you could store any values within that range in an int variable. Unsigned int would have a range of 0 to 64K. Just google it to know more.

[flyhigh]

im getting an error at this line.
Person Per ;{

the error is

 error C2447: '{' : missing function header (old-style formal list?)

am i doing something wrong
thanks

#include <fstream> // for ifstream, ofstream, ios_base
#include <iostream>// for cin, cout, endl
// you can just say `using namespace std;` here instead of all these 'using's
using std::ios_base;
using std::cout;
using std::cin;
using std::endl;

// just creating a constant for the name of the database
static const char *DATABASE_FILE = "pr1.bin";

// the data that will go into the database
struct Person {

  char name[8];
   int Features;
   int FFVersion;  
   int DataOffset;
   int TimeStamp;
  char CreatorApplication[4];
   int CreatorVersion;  
   int CreatorHostOS;
   int OriginalSize;
   int CurrentSize;
   int DiskGeometry;
   int DiskType;
   int Checksum;  
   int UniqueId;
   int SavedState;
   //int Reserved;

};


Person  Per ;{



    name = williamc;
    Features = 0000;
    FFVersion = 0100;  
    DataOffset = FFFFFFFF;
    TimeStamp = 1000;
    CreatorApplication = wmc ;
    CreatorVersion = 0100;  
    CreatorHostOS = Wi2k;
    OriginalSize = 5243392;
    CurrentSize = 5243392;
    DiskGeometry = 00065535;
    DiskType = 0002;
    Checksum = 0512;  
    UniqueId = 1234567812345678;
    SavedState = 1;
}








// this function takes a pointer to a Person struct
// that will be filled with the data in the file
bool LoadDB(Person *per) {
  // first parameter is the name of the file
  // second is the open flags. 
  //    `in` says you will read from the file
  //    `binary` says you will read binary data instead of simple text
  std::ifstream fin(DATABASE_FILE, ios_base::in | ios_base::binary);
  
  // if we couldn't open the file (it may not exist); fail
  if (!fin.is_open())
    return false;
  
  // the file is open; tell the read function to look at `per` as a
  // char pointer instead of a Person pointer so that `fin` can place
  // one byte at a time into the struct
  // the second parameter tells read() how many bytes to read
  // Note: do not use the ">>" operator to read from a binary file 
  fin.read((char*)per, sizeof(Person));
  fin.close();// close the file - not necessary, but we should be neat

  // success  
  return true;
}

// this function takes a pointer to a Person struct
// that will be written into the file
bool SaveDB(Person *per) {
  // these flags say:
  //    `out` - we will be writing data into the file
  //    `binary` - we will be writing binary data and not simple text
  //    `trunc` - if the file already exists, truncate (wipe out) the existing data
  std::ofstream fout(DATABASE_FILE, ios_base::out | ios_base::binary | ios_base::trunc);
  // couldn't open it (disk error?); fail
  if (!fout.is_open())
    return false;

  // notice this time we cast the Person pointer to a const char* because we aren't
  // altering the structure this time; rather we're just looking at it's contents.  
  fout.write((const char*)per, sizeof(Person));
  fout.close();// close the file - not necessary, but we should be neat

  // success  
  return true;
}

int main() {
  // create an empty person struct
  Person per;
   
  // load the data in the db file
  if (LoadDB(&per)) {
    // print what we loaded into our Person struct
    cout << "Loaded Database...\n";
    cout << "Name = " << per.name << endl;    
    cout << endl;
  }
   
 
  // save the new user-entered data  
  if (SaveDB(&per))
    cout << "\nDatabase saved!\n";
  else
    cout << "\nUnable to save database!\n";

  system("pause");

  // return 0 on success (main() should never be void!)
  return 0;
}

[szlamany]

This

Person Per ;{

should be this

Person Per {

I would believe...

[flyhigh]

nope tried that .

yall have a good mothers day


thanks all

[akhileshbc]

Try accessing it's member's using the dot on the object.

Example:

Person  Per ;
    Per.name = "williamc";
    Per.Features = 0000;
    Per.FFVersion = 0100;  
    Per.DataOffset = FFFFFFFF;
    //...