Question

I’m having troubles with ofstream , which is – when I change value of ofstream object like this

ofstream o_save; 

/*code*/

o_save = ofstream(filename);  //Problem is here

…the line above completely erase contents of file.

The question is how do I legitimately change filename value of ofstream object ?

P.S. I cant define it when I declare it, because I want it global and I’m not sure which save file I select.

Answer 1

The question is quite vague and contradictory, and the OP seems to have slept after asking the question. So I shall try to peek inside his head and try to elaborate what he wants.

For opening a file, there are many modes for that. Open it like this.

ofstream o_value ;
o_value.open("file.txt") ;

If you want to preserve the original contents of that file, use..

o_value.open("file.txt", ios::app) ;

If you want to close it later and open another one, close using…

o_value.close() ;

Chaning of file names is normally not allowed in case of ofstream. You can use rename from <cstdlib>. You can delete a file though using remove("file.txt") in <cstdio> .