Thread: Functions and pointers

Dear friends,

I have previosly posted part of this code. I am improving on it to take its input from a file and output to another file. I am also trying to make it more user interactive.

I achieved writing the program output to a file using:

ofstream file_op("c:\\file.txt",ios::app);
file_op<<n;
file_op.close();


I am using CV++ 6.0 to compile this code. The following errors are reported. Can someone please help me
learn how to remove these errors.

Compiling...
encrypt2Function.cpp
C:\encrypt2Function.cpp(36) : error C2664: '__thiscall std::basic_ifstream<char,struct std::char_traits<char> >::std::basic_ifstream<char,struct std::char_traits<char> >(const char *,int)' : cannot convert parameter 1 from 'char' to 'const char *'
Conversion from integral type to pointer type requires reinterpret_cast, C-style cast or function-style cast
C:\encrypt2Function.cpp(80) : error C2181: illegal else without matching if
C:\encrypt2Function.cpp(100) : error C2601: 'Interface' : local function definitions are illegal
C:\encrypt2Function.cpp(131) : error C2601: 'EncDec' : local function definitions are illegal
Error executing cl.exe.

encrypt2Function.obj - 4 error(s), 0 warning(s)

My code is

Code:

#include <iostream>
#include <string>
#include <time.h>
#include <conio.h>
#include <fstream>

#define DATA	 0x378  //Data Register base address
#define STATUS   DATA+1 // Status Register address
#define CONTROL  DATA+2  //Control Register address


using namespace std;

//Function prototyping

void Interface (ifstream &fin, char (*Secure)(char c));

char EncDec (char c);

//main (): manage file stream extraction

int main ()

{

	const int MaxFileNameSize=256;

	// prompt and extract the name of the file

	cout<<"Enter the name of the file:"<<flush;

	char FileName;

	//validate the file name provided

	ifstream fin (FileName);

	if (fin)

	{
		//we have a valid file, so determine the action

		cout<<"The file contents to be made secure through"

			<<"bit level transformation (Y,N):"<<flush;

		char reply;

		cin>>reply;

		//process the file according to the user request

		switch (reply)

		{

		case 'Y':

			Interface(fin, EncDec);

			break;

		case 'N':

			cout<<"File is left in plain version";

			break;

		default:

			{

				cerr<<"Bad request"<<endl;

				return 1;
			}

		}

	else 

		{

			cerr<<"Invalid file name:"<<FileName<<endl;

			return 1;

		}

return 0;

}

	//Interface (): Manage the interface to the stream cipher 

	//using the EncDec () function.

	void Interface (ifstream &fin, char (*secure)(char c))

	{

		//Extract, modify and save one-character-at-a-time 

		//from the file.

		char CurrentChar;  //currenrly extracted character

		while (fin.get(CurrentChar))

		{	//modify and save the current character using
			//Secure()

			CurrentChar=(*Secure)(CurrentChar);

			ofstream   file_op("C:\\CodeOutput file_out.txt"), ios::out);

			file_op<<CurrentChar;

		}

		return;

	}

	//EncDec(): manage writing to and reading from the 

	//standard parallel port.

	char EncDec (char c )

	{
		char s, n;

		_outp(CONTROL,_inp(CONTROL)&0xF0|0x04); /*initialise the
																CONTROL port for data input*/

		_outp(DATA, s);   /*write c to the DATA register*/

		clock_t start_time;

		start_time=clock();

		while ((clock()-start_time)<0.25*CLK_TCK);//propagation delay time

		n=(_inp(STATUS)&0xF0);  /* read MSnibble*/

		n=n|(_inp(CONTROL)&0x0F);/*Read LSnibble*/

		n=n^0x84; /*toggle bit 2 and 7 */
		/*pins 11(bit 7)-BUSY- is hardware inverted. Pin 16 has been inverted by the external 		hardware*/
					
		return s;
	

	}

}

Code:

char FileName;

This is a single char. Either declare an array like this

Code:

char FileName[MAX_PATH];

or use a string object

Code:

string FileName;