Thread: Looping code with a viable ios::noreplace code

Ok this topic may make no sense at first but here's the code I'm having trouble with.

Code:

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

using namespace std;

int main()
{
.............................

while(!savefile.is_open())
{
	cout << "Please give me a name." << endl;
	getline(cin, name, '\n');
	fstream savefile (name.c_str(), ios_base::in);   //To check if file exists
	if(!savefile)                                                        //If file doesn't exist,  create it.
		ofstream savefile (name.c_str())
		 
	else                                            //If file does exist loop back and ask for dif name
		cout << "Name already in use. Please choose another name." << endl;
....................................
}

Ok heres what is happening with this code when compiled and ran. It is able to tell me the file exists and will ask for input of a dif file name (so getting into the loop works fine).
The problem is when i give it a name that doesn't exist. It'll take the name and create the folder yet it'll loop back to asking for a name again rather then breaking the loop. It'll do this no matter how many times i give it a new name.

Heres what I have tried.
I've tried making sure the file is open with savefile.open(name.cstr()) (still loops after new name entered).
I've tried the condition for while to be !savefile.
I've tried a do while loop with condition being both !savefile and !savefile.is_open()
I can't remember much else but I'm sure my problem relys in the condition and can probable be fixed with an extra in variable. Kinda like this.

Code:

int x = 0; //new variable

while(x!=1)
{
	cout << "Please give me a name." << endl;
	getline(cin, name, '\n');
	fstream savefile (name.c_str(), ios_base::in);   //To check if file exists
	if(!savefile)
        {                                               //If file doesn't exist,  create it.
		ofstream savefile (name.c_str())
	        x=1;
          }	 
	else 
        {                                   //If file does exist loop back and ask for dif name
		cout << "Name already in use. Please choose another name." << endl;
                x=0;
          }

I have thought of this fix but am tring to find a fix that does not cause unnecessary variable.
Thanks for any help in advance.

You could use a while(1) loop and then break out after you save the file.

Also, are you using the same identifier name in 3 nested scopes? It looks like you've got a savefile in main, a savefile in the loop, and then another savefile in the conditional block... that's really asking for trouble, IMO.

Originally Posted by Medic87

fstream is not a defined variable in my int main(). Its just included file type so I'm able to use it. The first time the fstream recieves a variable name and variable (file.txt) is at the beginning of switch(variable) case1:. Which is where the code is located i was asking about. I'm not sure if this clears up a little but i don't use savefile anywhere but here. I just couldn't compile it without it declared with in {} with in the switch case because of an error message of variable skipped in case 2: or something of that nature. So yes its been declared within the switch case as

Code:

 fstream savefile;

and then opened in the loop to check to see if file exists, but if the loop is within the same {} then i don't see a double nestle here. Maybe a bit more explanation on what is meant as i have it nestled in 3 areas?

OK, I understand more what you mean now. I have toyed with the code for just a few min and realized that all i needed to do was declare the variable fstream under func main. after this is done the switch case doesn't matter.

Code:

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

using namespace std;

int main()
{
// Declare variables
int c, x, b;
string a;
fstream savefile;

//after savefile declared here as a fstream  i can write the noreplace replacement like this

switch(x)
case1:
savefile.open (name.c_str(), ios_base::in); //Just savefile.open instead of fstream savefile in first post

if(!savefile) //If file doesn't exist,  create it.				
{					
savefile.open (name.c_str()); //same here
savefile << name << endl;

}
else    //If file does loop back and ask for dif name
{
cout << "Name already in use. Please choose another name." << endl;
}

I didn't include the loop in this paste though because I already figured that out. But now my program no longer names savefile as fstream 3-4 times nestled in different brackets.

Code:

fstream savefile; //In main an then

fstream savefile(name.c_str()); /* In switch and again in loop. Just showing i know what you mean now  and thanks for help*/

Thx again for pointing that out to me so i'm no longer saying savefile is an fstream throughout three different brackets.
And I also found out the reason for the switch case error is that instead of anouncing my fstream as savefile right after main before i use switch case i was trying to just announce it in case 1: which gave me the error.