Printing File Data (Via a Printer)

[Salchester]

I am currently making a program that will read information from a file, but, i would also like to allow the user to print the current record(s) from the file via a printer. How can this be done.

Many Thanks

Here's the coding i have so far:

#include <iostream.h>
#include <fstream.h>
#include <ctype.h>
#include <conio.h>
#include <dos.h>

int main(void)
{
int id;
char name[50];
char next;

ifstream data (".\\data.txt");
do
{
clrscr();
data >> id;
data >> name;
cout << "ID: " << id << endl;
cout << "Name: " << name;
cout << "\n\nShow Next? Y/N: ";
cin >> next;
next = toupper (next);
} while (next == 'Y');
data.close();
return 0;
}

[Locutus]

Your includes seem to suggest you're talking about DOS-style printing, in which case I *think* you should simply be able to do something like this:

std::ofstream printer("LPT1", std::ios::binary);

Btw, although writing "int main(void)" isn't wrong as such, it is generally considered bad style. Just stick to "int main()", IMO.

[Salchester]

How do i print using basic coding, i don't understand the coding you supplied. I am sort of just a beginner.

Would i need to put the path of the file in the code as well, if so where do i put it?

Many Thanks

[Valmont]

Experiment with this:

std::ofstream printer("LPT1", std::ios::out);
std::string MyString("Hello everybody!");
printer << MyString;

[Salchester]

Can you use basic coding please, as i don't understand this! I haven't got a clue on how this works.

How come everybody uses the std:: coding?

Many Thanks

[Locutus]

Originally Posted by Salchester

Can you use basic coding please, as i don't understand this! I haven't got a clue on how this works.

How come everybody uses the std:: coding?

Many Thanks

Namespaces you mean?

In short, namespaces are a way to group related stuff, like groups of functions and variables together.

Suppose you declare a namespace "my", with a function "f"

namespace my
{
        void f();
}

You can then call f() by writing

my::f();

Apart from keeping your code organised, one of the more usefull things about using namespaces is that it helps prevent name clashes.

Suppose you had two headers, my.h and your.h, each of which declare a number of functions and variables.

//my.h
int i;
void f();
bool g();

//your.h
char c;
void f();
void h();

Now, you can't include both at the same time, because the function "void f()" is declared in both headers.

If, on the other hand you put the declarations each in their own namespace, you can.

//my.h
namespace my
{
        int i;
        void f();
        bool g();
}

//your.h
namespace your
{
        char c;
        void f();
        void h();
}

And call with

my::f();
your::f();

There is actually a lot more stuff to know about namespaces, but that's pretty much the basis. Pretty much all the stuff in the standard library is inside the namespace "std", thus all the stuff like std::string, std::ofstream, etc.

For historical reasons however, there are usually two "versions" of most headers in the standard library. Eg, #include <string.h> and #include <string>, #include <iostream.h> and #include <iostream>, etc.

The difference is that the "traditional", .h versions of the headers declare everything in the global namespace, while the versions without the .h put it inside the "std" namespace.

#include        <iostream>

int main()
{
        std::cout << "Hello World!" << std::endl;

        return 0;
}

vs

#include        <iostream.h>

int main()
{
        cout << "Hello World!" << endl;

        return 0;
}

The version with namespaces is generally preferred.

[Valmont]

You could also spend some time in this thread:
return types