[RESOLVED] File name change

[A_Singh]

Here’s my code to create a file to c ++.
Code:

#include <iostream>
#include <conio.h>
#include <fstream>
using namespace std;

int main()
{
        ofstream myFile;
        myFile.open(’’test.txt’’);
        myFile.close();

_getch();
return 0;
}

What I want is that first time I run the program, the file created should be: test, second time: test1, third time: test2 etc...
How can I do that .?
Please help !

[2kaud]

Try to open the file for input. If the file exists then add 1 or 2 or 3 etc to the file name and then try to open again. Repeat until the file doesn't open. Then you have the name of the new file to create.

A refinement is to save the last created name in an ini file or registry and use that as the start basis for the above method.

[A_Singh]

Can't figure it out. Any more suggestions?

[VictorN]

Can't figure it out. Any more suggestions?

2kaud suggested you the simplest way to implement what you asked.
What is the problem to implement it?

[A_Singh]

I didn't understand that.

[A_Singh]

I'd appreciate if someone can write that in simple language.

[VictorN]

I'd appreciate if someone can write that in simple language.

Define "simple language".

[A_Singh]

Write that in an easily understandable manner, ok ?

[2kaud]

Write that in an easily understandable manner, ok ?

It was!

This code will create 10 different named files starting from test1 to test10 (assuming they don't already exist!).

#include <string>
#include <fstream>
using namespace std;

string newfile()
{
	const string filstem = "test";
	const size_t fnumstart = 1;

	string filnam;
	size_t fnum = fnumstart;

	for (ifstream ifs; ifs.open(filnam = filstem + to_string(fnum++)), ifs.is_open(); ifs.close());

	return filnam;
}

int main()
{
	for (size_t i = 0; i < 10; ++i)
		ofstream ofs(newfile());
}

[A_Singh]

Thanks 2kaud , you are definately a professional programmer to answer all my queries.

[A_Singh]

Actually I want my first run of the program of create test, second test1, third test2. Etc..
Your program creates these files in one run only.

[2kaud]

Actually I want my first run of the program of create test, second test1, third test2. Etc..
Your program creates these files in one run only.

My test program just uses a loop to create the 10 files for testing.

int main()
{
	//for (size_t i = 0; i < 10; ++i)
		ofstream ofs(newfile());
}

This will just create the next file in sequence for each time the program is run. The code in main() is just a test of newfile() function.

[A_Singh]

Thanks 2kaud it's resolved.
By the way, do you know that whenever we edit a .XLSX (excel) file using c++, after editing excel shows the file as corrupt, any solution to that?

[2kaud]

Also note that if you ant the file names to start test, test1, test2 rather than test1, test2, test3 then consider

string newfile()
{
	const string filstem = "test";
	const size_t fnumstart = 0;

	string filnam;
	size_t fnum = fnumstart;

	for (ifstream ifs; ifs.open(filnam = filstem + (fnum ? to_string(fnum) : "")), ifs.is_open(); ifs.close(), ++fnum);

	return filnam;
}

[2kaud]

By the way, do you know that whenever we edit a .XLSX (excel) file using c++, after editing excel shows the file as corrupt, any solution to that?

That would depend upon how the c++ code interacts with the .xlsx file.