Question

File.Copy allows simple file copying. When a duplicate file name is encountered, File.Copy has a third parameter to determine if the original file is overwritten or not.

Is there a built-in .Net function that allows a third option to rename the copied file and hence keep both files?. For example, the file copy would automatically rename “readme.txt” to “readme – Copy.txt” if another readme.txt already existed in the destination folder – similar to Windows Explorer functionality?

I realize it can be written but didn’t want reinvent the wheel if it exists.

Thanks in advance.

Answer 1

There’s nothing you can do all-in-one go with File.Copy, however you could test if the destination exists and then Move instead.
Move takes two parameters, and you can essentially rename at the same time.

if File.Exists(destinationPath) {
    File.Move(source, destinationPathRenamed);
} else {
    try {
        File.Copy(source, destinationPath);
    } catch (IOException ex) {
        // destinationPath file already exists
        File.Move(source, destinationPathRenamed);
    }
}

See Move documentation

EDIT:

Updated code above. @xanatos makes a good point about atomic operation. I made no assumptions about whether there are other processes accessing the file(s).

Note that I haven’t added other error handling for the source file being deleted before the operation begins either.