A better way?

**ajb268** · 01-13-2005

This is an old file that I would like to update, I have tried to convert everything over to string but it ended up a failure wasn't sure what functions to use and classes. The buffer flushes fix the naggin getline bug which I have fixed in another prog but for some reason I the warnings came back when I starting working with this one. If anyone has some suggestions on updating this that would be great.

Code:

#include "stdafx.h"
#include "test1.h"
#include "stdlib.h"
#include "iostream.h"
#include "fstream.h"
#include "string.h"
#include <io.h>
#include <string>
#include <vector>
#include <stdio.h>
#include <iomanip.h>
#include <strstrea.h>
#include <time.h>
const int lineSize = 501;

int Annotate ( const char *inSource2)
/* Searches given file with user entered keycodes and appends
to the user given file with the extension of .all*/


{
	ifstream fin;
    ofstream fout;
	char	 	s2Line[lineSize];			// for data lines
    char filename [10];
	char keyCode [8];//keycode buffer string 
	int	source2Line = 0;
	int keynum;
	char bs[2];//buffer flusher
	
	cout << "What's your File Name? ";
	cin.getline (filename,11);
	strncat (filename, ".all", 6);
	cout << "Your File Name is " << filename << ".\n";
	cout<<"How many Key Codes in this file? ";//Allows for multiple keycodes in same file.
	cin>>keynum;
	cin.getline(bs,2);//flushes the buffer
	
	while (keynum!=0)
	{
	ifstream 	source2(inSource2, ios::in);
	--keynum;
	cout << "Enter a Key Code? ";
	cin.getline (keyCode,9);//sends a keycode no longer than 9 char long to keyCode
	cout << "Your keycode is " << keyCode << ".\n";
	fout.open(filename,fstream::in | fstream::out | fstream::app);//opens the .all file in append mode			
	
	if (!source2) 
	{
    	cerr << "Can't open input files\n";//Error protection!
		return -1;
	}
	
	while (source2.getline(s2Line, lineSize, '\n')) 
	{
		char subString[30];
		strncpy (subString,s2Line,29);
		
		if (strstr(subString, keyCode) != 0)//Only searches the first 30 columns 
		{ 
		
		fout<<s2Line<< endl;//Writes the whole line and returns to the next line
		
		}
	}
	source2.close();//closes the master file
	fout.close();//closes the new parsed file
	
	}
	
	
    
	return 0;
}

int main (void)
{
	char ans[2];//buffer flusher
	int Groupnum;
	cout<<"How many files? ";
	cin>> (Groupnum);
	cout<<"Your number is "<<Groupnum<<endl<<endl;
	cin.getline(ans,2);//flushes buffer
	while (Groupnum !=0)//allows you to enter multiple files 
	{
	Annotate("test.all");
	--Groupnum;
	}
	return(0);
}

**pianorain** · 01-13-2005

Sure. First, let's get rid of most of those includes:

Code:

//These are all you need
#include <iostream>
#include <fstream>

However, you'll need to use a few using directives (unless you want to go to each cout, cin, endl, etc. and put a std:: in front of them.

Code:

using std::ifstream;
using std::ofstream;
using std::cout;
using std::cin;
using std::endl;
using std::fstream;
using std::ios;
using std::cerr;

There are a few places where you can use a string instead of a char array. I'll show you an example of one. First, be sure to #include <string> and put a using std::string; in. Then look at this section of code:

Code:

int Annotate ( const char *inSource2)
/* Searches given file with user entered keycodes and appends
to the user given file with the extension of .all*/
{
    ifstream fin;
    ofstream fout;
    char s2Line[lineSize];			// for data lines
//  char filename [10]; //old code
    string filename; //new code

By making that change, you'll have to change a couple of other lines. For instance, the getline right below it:

Code:

    cout << "What's your File Name? ";
//  cin.getline (filename,11); //old code
    getline(cin,filename); //new code

The string concatenation is also different, but intuitive and easy:

Code:

//  strncat (filename, ".all", 6); //old code
   filename = filename + ".all"; //new code

After those three changes, it should compile again. I'll confess that I didn't try to run it, so there may be some logical errors, but that's the gist of it.

**ajb268** · 01-14-2005

I have done some work with strings before but I don't understand the
using std:

fstream;
using std::cout;
using std::cin;
using std::endl;
using std::fstream;
using std::ios;
using std::cerr;
it seems when I used it before I add using namespace std or one of my other includes took care of it so why would that be considered better?

**pianorain** · 01-14-2005

The using namespace std; command brings the whole std namespace into the global namespace, which can lead to some ugly name collisions. That's not really a problem in smaller projects, but it can be in larger ones. Besides, it's like using a chain saw to carve out toothpicks. You might get it done, but it's easier to use something smaller.

The using std:: command only brings that particular command into the global namespace, so it's a whole lot easier to avoid name collisions.

If I'm coding something up in a hurry (read: sloppily), then I use using namespace std;. Otherwise, I use the using directive to bring in only the parts that I need.

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