ofstream filename

[joegi]

Hi,

I have a program where I need to periodically output some data to an external file. That is to say, each 10 iterations I want to save the info in sequentially numbered external files, something like this

out10.txt for ite 10
out20.txt for ite 20
out30.txt for ite 30

and so on. I wonder how can I implement this using ofstream in c++.


Thanks for your help,

Joel

[mcleano]

http://www.cplusplus.com/doc/tutorial/files/

[kevinkjt2000]

You may also want to mess around with strings some too to get the file-names like you want.
http://www.cplusplus.com/reference/string/string/

[Bazzy]

stringstreams do what you want:

int n = 10;
stringstream ss;
ss << "out" << n << ".txt";
file.open ( ss.str().c_str() );

http://www.cplusplus.com/reference/iostream/stringstream/

[joegi]

Hi,

thanks for your help. I am trying the following, but I dont get the desired results. Any suggestion?


#include <iostream>
#include <fstream>
#include <sstream>

using namespace std;

int main () {

ofstream fout;

int n = 10;

stringstream ss;

for(int i=1;i<=n;i++)
{

ss << "out" << i << ".txt";

fout.open ( ss.str().c_str() );

fout<<i;

fout.close();
}

return 0;

}

[Bazzy]

move the stringstream declaration inside the for loop. Otherwise the new file name will be appended to the previous contents of the stream

[joegi]

Sweet, now is working fine. Thank you very much for your help.


Cheers,

joel