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:

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#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:

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char FileName;

---

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

Code:

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char FileName[MAX_PATH];

---

or use a string object

Code:

---

string FileName;

---

Quote:

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Originally Posted by Quantum1024

Code:

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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;

---

---

Looking at these lines:

Code:

---

const int MaxFileNameSize=256;

// prompt and extract the name of the file

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

char FileName;

---

it looks like you meant to do this:

char FileName[MaxFileNameSize];

In addition, you never even read in the file name to begin with:

Code:

---

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

char FileName;

//validate the file name provided

ifstream fin (FileName);

---

You used the variable FileName to create your input stream, but you never assigned a value to FileName, i.e. you never read in the file name from the user.

Quote:

---

Originally Posted by Quantum1024

Code:

---

or use a string object
string FileName;

---

---

You should probably stick to char arrays, since the argument for this function:

ifstream fin(FileName)

has to be a char array. If you do use a string type instead of a char array, then you need to do this:

Code:

---

string FileName;

//read in FileName from user

ifstream fin(FileName.c_str());

---

which converts the string type to a char array type for the function.

Quote:

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C:\encrypt2Function.cpp(80) : error C2181: illegal else without matching if

---

Get rid of the parentheses(look up the format for a switch statement):

Code:

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default:

                {

                        cerr<<"Bad request"<<endl;

                        return 1;
                }

---

Quote:

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C:\encrypt2Function.cpp(100) : error C2601: 'Interface' : local function definitions are illegal

---

Because of your parentheses problem above, the compiler thinks your function definitions are inside main().