C++ program to remove comments from a file

error.cc

#include<iostream>
#include<string>
#include "error.h"
#include "/home/cs689/common/689.h"
/****************************************************************

   FUNCTION:   error

   ARGUMENTS:  string

   RETURNS:    void

   NOTES:      This prints the  error message
****************************************************************/

void error(string msg)//this is for printing the error message.
{
	cerr<<msg<<endl;
	exit(EXIT_FAILURE);
}

error.h

#ifndef TEST
#define TEST
#include<iostream>
#include<string>
#include "/home/cs689/common/689.h"
/****************************************************************

   FUNCTION:   error

   ARGUMENTS:  string

   RETURNS:    void

   NOTES:      This is declaration for the error function which prints error 
****************************************************************/
void error(string msg);
#endif

prog4.cc

#include <iostream>
#include "/home/cs689/common/689.h"
#include <fstream>
#include"prog4.h"
#include "error.h"
using namespace std;
/****************************************************************

   FUNCTION:   open_files()

   ARGUMENTS:  input file stream and output file stream

   RETURNS:    void i.e nothing

   NOTES:      This is used for opening the files and calling process_data() function
****************************************************************/
void open_files(ifstream& read,ofstream& write)//Definition for the open_files()
{
    string infile="prog4d.cc";//reading the file
    read.open(infile.c_str());//open the read file
    string outfile="prog4out.cc";
    write.open(outfile.c_str());//open the write file
    process_data(read,write);//calling the process_data() function
    return;
}
/****************************************************************

   FUNCTION:   process_data()

   ARGUMENTS:  input file stream and output file stream

   RETURNS:    void

   NOTES:      Removes the comment line part
****************************************************************/
void process_data(ifstream& read,ofstream& write)//Definition for the process_data()
{
	unsigned int number=0,position,flag1 = 0, flag2 = 0 , flag3 = 0;//I am using flags to check the different conditions we encounter
	if(read.is_open())
	{
	while(getline(read,s))//to read the whole file line by line
        {
		unsigned int i;
		string s1;
                position = s.size();
                flag2 = 0;
                flag3 = 0;
                for(i = 0 ;i<s.size(); i++)
                {
                        // this checks for the double quotes "
                        if(s[i] == '"' && flag1 == 0 && flag2 == 0 && number == 0)
                        {
  	                      flag3=1;
                              number = 1;
                              s1 += '"';
                              i++;
                        }
          		if(s[i] == '"' && flag1 == 0 && flag2 == 0 && number == 1)
              		{
                        	flag3 = 0;
                        	number = 0;
                        	s1 += '"';
                        	i++;
                        }

                        //this checks for Double-slash //
                        if(s[i] == '/' && s[i+1] == '/' && flag3 == 0 && flag1 == 0)
                        {
                                flag2 = 1;
                                position = i;
                        }

                        // This checks for slash-star /*
                        if(s[i] == '/' && s[i+1] == '*' && flag2 == 0 && flag3 == 0)
                        {
                                flag1 = 1;
                                i += 2;
                        }
                        if(s[i] == '*' && s[i+1] == '/' && flag2 == 0 && flag3 == 0)
                        {
                                flag1 = 0;
                                i += 2;
                                if(s[i] == '/' && s[i+1] == '*')
                                {
                                        flag1 = 1;
                                }
                        }
                        

                        if(flag1 == 0)
                        {
                                if(i < position)
                                {
                                        s1 += s[i];
                                }
                        }
                }
                write<<s1<<endl;
        
        }
}
else
{
error("Error in opening the file");
}
}
/****************************************************************

   FUNCTION:   close_files()

   ARGUMENTS:  input file stream and output file stream

   RETURNS:    void

   NOTES:      Closes the files
****************************************************************/
void close_files(ifstream& read,ofstream& write)//Definition for the close_file() function
{
read.close();//this is close the read file
write.close();//this is close the write file
}
/****************************************************************

   FUNCTION:   main

   RETURNS:    Integer

   NOTES:      Here we call the open_file and close_file contents 
****************************************************************/
int main ()
{
ifstream read;//variable for the input file 
ofstream write;//variable for the output file
open_files(read,write);//calling the open_files() function
close_files(read,write);//calling the close_files() function
}

prog4.h

#ifndef PROG4_H_INCLUDED
#define PROG4_H_INCLUDED
#include<fstream>
#include<iostream>
#include<string>
using namespace std;
void open_files(ifstream&,ofstream&);
void process_data(ifstream&,ofstream&);
void close_files(ifstream&,ofstream&);
char c1, c2;
string s;
unsigned int flag, flag2, flag3,position,num;
bool isInsideComment;
#endif // PROG4_H_INCLUDED

prog4out.cc

#include "/home/cs689/common/689.h"
#define DATA_FILE "/home/cs689/progs/p4/prog4d.d"

const unsigned MAXWORDS = 1000; 
const unsigned MAXLEN   = 20;   
const unsigned LINESIZE = 5;    

unsigned num_words = 0;         
char word_name [ MAXWORDS ] [ MAXLEN + 1 ]; 
char prog_name1 [ ] = "// Begin Program Data //";
char prog_name2 [ ] = "/* End Program Data */";



void get_words ( );                         
void print_words ( );                       
void clean_entry ( char [ ], char [ ] );    



int main ( )
{
    get_words ( );      
    print_words ( );    

    return 0;
}





void get_words ( )
{
    int c; unsigned n = 0;
    char entry [ MAXLEN + 1 ], save [ MAXLEN + 1 ];
    FILE* fptr = fopen ( DATA_FILE, "r" );

    




    while ( fscanf ( fptr, "%20s", entry ) != EOF ) {
        if ( strlen ( entry) == MAXLEN ) {
            while ( !isspace ( c = cin.get ( ) && c != EOF ) );
            if ( c == EOF ) break;
        }
        clean_entry ( entry, save );

        


        if ( !strlen ( save ) ) continue;

        



        if ( ++n > MAXWORDS ) break;
        assert ( strcpy ( word_name [ num_words++ ], save ) );
    }

    fclose ( fptr );
}







void clean_entry ( char e [ ], char s [ ] )
{
    int i, j;       
    char c;         

    
    for ( i = 0; ( c = e [ i ] ) && !isalnum ( c ); i++ );
    for ( j = i; ( c = e [ j ] ) &&  isalnum ( c ); j++ );

    
    strcpy ( s, e + i );
    s [ j - i ] = 0;
}





void print_words ( )
{
    cout << prog_name1 << endl;
    cout << "Number of words: " << num_words << endl << endl;

    for ( unsigned i = 0; i < num_words; i++ ) {
        cout << " " << word_name [ i ];
        if ( i % LINESIZE == LINESIZE - 1 || i == num_words - 1 )
            cout << endl;
    }
    cout << endl << prog_name2 << endl;
}