Newbie question: How to "save as" an existing text file

Can someone please help me on this?

I need to make a copy of an existing .txt file and save it under a different name. The original file needs to be preserved so a simple "rename" can't do the trick. I've been searching on the web and the only way I found was to read the existing file into some sort of a data structure, e.g. vector<string>, then dump the whole thing into a new .txt file.

I'm a bit concerned that the files are pretty big so is there a better way of doing this, please? Many thanks.

Yes, a copy command will do the trick.
Open cmd and type "copy spath\sorcefile.txt dpath\destfile.txt"

[edit]
Windows Assumed

Hi siavoshkc,

Thanks very much for your reply. The code you suggested is indeed a dos command. So did you mean I put this line in a batch file the execute it in my C++ program?

p.s. sorry that I didn't say clearly in my original post that I was looking for solutions in C++

Thanks again

If its a programming practice. You create a memory buffer. Load data into it. Save it somewhere else or with a different name. If the file does not fit in memory, do the same thing in a loop to copy whole of it.

If it is not a programming practice tell me what it is.

Sorry, me again. I think I found the solution:

system("copy c:\\org.txt c:\\dest.txt");

Thanks again for your help.

Quote:

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Originally Posted by siavoshkc

If its a programming practice. You create a memory buffer. Load data into it. Save it somewhere else or with a different name. If the file does not fit in memory, do the same thing in a loop to copy whole of it.

If it is not a programming practice tell me what it is.

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Yup, it's a programming practice, in c++

and here's the original page where i found the solution
C++ copy / delete file

Quote:

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Originally Posted by suny

Sorry, me again. I think I found the solution:

system("copy c:\\org.txt c:\\dest.txt");

Thanks again for your help.

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If it satisfies you, right. But you are not programming, you are just executing a written program. You should write its code yourself if you really want to learn programming.

BTW it is generally a bad practice to use system().

Quote:

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Originally Posted by siavoshkc

BTW it is generally a bad practice to use system().

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At best, it is non-portable. At worst, it is a security hole.

Under windows (which is the system where examples in preceding posts will typically work) the win32 SDK has a function named CopyFile() that will have the required effect. Catch is, that is also non-portable (only works on Microsoft operating systems).

Right. Thank you both.