Compare Two Folders
Compare Result Types
If two folders (Folder 1 and Folder 2) are compared for the similarities and differences that exist between them, in terms of the files they contain, then for a file with a given name, in a given directory, we will obtain the following:
- Files that are found only in Folder 1. These are referred to as Folder 1 Only files.
- Files that are found only in Folder 2. These are referred to as Folder 2 Only files.
- Files that are found in both folders. If the files are found to be the same according to specific comparison rules then they are referred to as Same files.
- If the files are found to be different according to these comparison rules then the are referred to as Different files.
Note 1: The terms "Same" and "Different" are not absolute. They are used only in terms of certain comparison criteria. So the program is not saying "These files are absolutely the same (or different)", it is only saying that they are the same (or different) as per the specified comparison criteria.
Note 2: Comparisons are made for a given file name in a given directory. So if two files are identical, but are in different directory locations, then they will not be considered as being "found in both folders", and so cannot be said to be Same or Different, and so will be considered as Folder 1 Only and Folder 2 Only files respectively.
Comparison Criteria
By default, files are considered equal if they have the same size AND timestamp. If either of these are different, then the files will be considered different.
The Project Settings -> Compare page has a "perform binary comparison" option. If this is checked, then files will be considered equal only if every byte of both files are the same.
Note: Files can have the same size and timestamp and yet still contain different binary data. Eg. If you save two files at the same time, one contains the line "The Frog" and the other contains the line "The Forg", they will be the same size, but not all bytes are the same. Conversely, files can be identical on the byte level but still have different timestamps. (They will of course have the same file size).
Source Settings
When it comes to copying files from one folder to the other, then for Folder 1 Only files, it is obvious that you want to copy them to Folder 2 (unless you're copying to another location). Likewise for Folder 2 files, it is clear you want to copy them to Folder 1.
But what about Same or Different files, that are common to both folders? Which direction do you want to copy these files? It is not clear because these files exist in both folders.
Compare Advance has the concept of "Source Settings" by which you can set the folder source for a given file, to be used in a copy operation. Same and Different files are however, handled differently.
(Source Settings Options)
For Same files, there is a global setting: In the Project Settings-> Compare page, you can "Set source of Same files" to either Folder 1 or Folder 2. The default is Folder 1. However, because the files are "Same", you will generally not want to include them in copy, synchronization or backup operations. Still, this setting may be important in some cases.
For Different files, you set the source on a per-file basis. In the Project Settings-> Compare page, you can choose to "set the source of different files" based on date (newer/older), size (larger/smaller) or folder (folder 1/folder 2). The default setting is: by date->newer.
After comparing the two folders, each Different file has it's source set according to this setting. This setting is displayed in the "Src" column of the file display. You can change the source setting for a selected file or group of selected files, by bringing up the popup menu (right click) and selecting the "Set source" menu item, and then clicking on the folder you want to be the source for this file or group of files.
(File display popup menu) |
