Assignment No. 03 Cs201 Total Marks: 20 Due Date: 10/07/2015

[Ayeeza]

Please read the following instructions carefully before submitting assignment.

It should be clear that your assignment will not get any credit if:

 

• The assignment is submitted after due date.
• The submitted assignment does not open or file is corrupt.
• Assignment is copied(partial or full) from any source (websites, forums, students, etc)

 

 

Objective

 

The objective of this assignment is:

• Learn to code, edit, compile and execute C++ program.
• Learn to manipulate and navigate through text files.
• Learn to create and use user defined functions.
• Learn to use string manipulation functions.

Guidelines

 

• Code should properly be indented and well commented.
• Follow C/C++ naming conventions while using variables, functions etc.
• Use only Dev-C++ for this assignment. If you are using any other tool then mention it at top of your code file as comments.

 

Assignment Description

 

In this assignment, you are required to write c++ code that will protect the provided text file using the protection mechanism given in guidelines. It will also check the security of file and if any change is made in the contents of protected file, it will point out the file as changed.

 

Protection mechanism:

The program will protect the file by generating a protection key on the basis of contents of the file. The key will be saved at the end of the file with “%” symbol as prefix. This key will be used to detect either the file contents are changed or not e.g. if file contents are changed the new key generated will not match the existing one, leading to conclusion that file contents have been changed.

 

Solution guidelines

The program should operate in following sequence.

• Program will prompt the user to enter the file name in current directory.
• System will show a menu with two options:
  • Protect the file
  • Check security status
• In case user selects the first option (i.e. protect the file), the system will perform the following steps:
  • Read the file
  • Check if the file is already protected or not.
  • In case if file is not protected, program will protect it by the protection mechanism defined above.
  • If file is already protected, system will display appropriate message and exit.
• If user selects the second option (i.e. check security status), the system will perform following steps:
  • Read the entire file and if key does not exist (i.e. file is not already protected), program will display the message to protect the file first and display menu.
  • If file is already protected, the system will read the contents along with the already existing key. On the basis of contents read, a new key will be generated. If this new key and the existing one (read from the file) do not match, it means that the contents of protected file are changed and vice versa.

 

Important note

A text file (data.txt) is attached with assignment, use it for protection checking. Video file (Output-Demo.mp4) of desired function is also attached with assignment. Watch the demo video carefully to understand the required functionality (output) of program. Your program should work as per functionality performing in demo video file. You do not need to send text file with your solution. Just upload .cpp file from your LMS account. For any query related to assignment no. 3 contact us at [e-mail].

Submission

You are required to submit your solution C++ program through LMS i.e. .cpp file. 

[+ M.Tariq Malik]

#include <iostream>
#include <string>
#include <cstring>
#include <fstream>

using namespace std;

int GenerateKey(string file){
int key = 0;
ifstream myfile();
//int val = 0;
if (myfileis())
{
string line = "";
while (getline(myfile, line))
{
key += line.length(); 
}
return key;
}
}
bool findKey(string);

int ProtectFile(string filename){
int key = GenerateKey(filename);
string mykey = "%";
ofstream myfile;
myfile.open(filename,ios::out |ios::app);
mykey += to_string(key);
myfilemykey;
myfile.close();
return key;
}
int getfileLength(string);
int GetKey(string);
int displayMenu(string filename){
bool check = false;
int key = 0;
int msg = 1;
check = findKey(filename);
int getval = 0;
cout"\nOperations on text file\n";
cout"1. Protect my text file\n";
cout"2. Check Security of my text file\n\n";
cout"Enter your choice (1/2): ";
cin>>getval;
if(check == false && getval == 2){
msg = 1;
}else if(check == false && getval == 1){

key = ProtectFile(filename);
msg = 2;
}
else if(check == true && getval == 1){
//checkForChange();
msg = 3;
}
else if(check == true && getval ==2){
if( GetKey(filename)==getfileLength(filename)){
msg = 4;
}
else if(getfileLength(filename)!=GetKey(filename)){
msg = 5;
}

}
return msg;

}
bool findKey(string filename){
bool check = false;
string key = "%";
string line = "";
ifstream myfile;
myfile.open(filename, ios::in);
size_t pos;
while(myfile.good())
{
getline(myfile,line); 
pos=line.find(key); 
if(pos!=string::npos) 
{
check = true;
break;
}
}
return check;
}
int getfileLength(string filename){
ifstream myfile (filename);
int val = 0;
int key = 0;string line;
if (myfile.is_open())
{ 
while (getline(myfile, line))
{
size_t pos = line.find('%');
if (pos != string::npos)
{
line = line.substr(0,pos);
}
val += line.length();
}

}
myfile.close();
return val; 
}
int GetKey(string filename){
ifstream myfile (filename);
int val = 0;
int key = 0;string line;
if (myfile.is_open())
{

while (getline(myfile, line))
{
size_t pos = line.find('%');
if (pos != string::npos)
{
line = line.substr(pos+1);
}
}
}
myfile.close();
return atoi(line.c_str()); 
}
int main(){
string filename = "";
int key = 0;
bool choice = false;
int msg = 1;
ifstream myfile;
cout"Enter the name of text file in current directory: ";
cin>>filename;

myfile.open(filename);
if(!myfile){
cout"\nSorry the name of file "filename" you entered is not exist in current directory!";
return 0;
}else{
while(msg == 1){
msg = displayMenu(filename);
if(msg == 1)
cout"Your text file is not protected, first protect it by using option \"1\"\n\n";
if(msg == 2){
cout"\nYour text file is protected now!";
break;
}
else if(msg == 3){
cout"\nYour text file is already protected!";
break;
}
else if(msg == 4){
cout"The content of file are not changed after protection.";
break;

}else if(msg == 5){
cout"Alert! The content of file are changed after protection.";
break;
}

}

}

coutendl;
system("pause"); 
}

[Sohail Qureshi]

where is if myfileis() function is declared? 

[+ M.Tariq Malik]

#include
#include
using namespace std;

int get_key(string a_lines)
{ int key = 0;
key += a_lines.length();
return key; }

bool findkey(string a_lines)
{ int answer = a_lines.find("%");
if(answer >= 0)
{ return 1; }
else
{ return 0; } }
bool readkey(string a_lines)
{

}
main()

{ ifstream infile;
ofstream outfile;
char fName[100];
string line;
string lines;
int option;
cout "Enter the name of text file in current directory:";
cin >> fName;
infile.open(fName, ios::in); // opening file in input mode
bool jump = true;
bool answer;
if(!infile)
{ cout "file not found choose 1"; }
else
{ while(!infile.eof())
{ getline(infile, line);
lines += line; }
infile.close();
do
{ cout "\nOperations on text file";
cout "\n1.Protect my text file";
cout "\n2.check security of my text file";
cout "\n1.Enter your choice (1/2)";
cin >> option;
switch(option)
{ case 1:
if(findkey(lines))
{ cout "already protected";
cout " and return " findkey(lines);
infile.close();
jump = false;
break; }
else
{ outfile.open(fName, ios::app);
outfile "%";
outfile get_key(lines);
cout "key added";
cout "and return " findkey(lines);
jump = false;
outfile.close();
break; }
case 2:
if(findkey(lines))
{ cout "file is protected using option 2";
cout "and return " findkey(lines);
jump = false;
break; }
else
{ cout "file is not protected please protect file";
cout "and return " findkey(lines);
jump=false;
break; } } }



while(jump == true);
system("pause");
} }

[abid hussain]

tarik bai ye complet assignment hai???