A Show Duplicate files function may be used to find duplicate files in two or more directories. However, the active file window must first be showing multiple directories. To use the Find Duplicates function, add the directories of interest to the active file window by either;
Either of these actions has the potential to read more than one file of the same name into the active Files window. Continue to add directories until all directories of interest are in the file window. To read the entire drive into the file window, Ctrl+Shift+LMB double click on the root directory. Multiple directories in the same window are indicated by a bright red title bar.
Use Multiple Directories in conjunction with Multiple Trees moding to find duplicate files on different drives. This combination allows reading and combining directories from different drives into the same window.
You should limit the search to only those directories of interest. It is also recommended that file filters be used to limit the extent of the search whenever possible. The technique is to use multiple file filters, i.e.*.EXE;*.DOC;*.TXT;*. BAK;<1-1-95 which would limit the files read into the window to these extensions and only those dated before 1-1-95, so that the number of files being examined is more limited. The function performs more slowly when there are a large number of duplicate files. During tests on a P133, the search speed was found to be about 3000-4000 files/minute when several thousand files were being compared. This is primarily a CPU intensive task so the performance will vary with the CPU processing speed.
Note: Filters must be set before reading directories!
When the directories desired for finding duplicates are in the file window, select the menu option Files->Compare->Show Duplicates. There are five submenu choices to choose how the files are compared to find duplicates;
CRC - same 32-bit CRC
Name - same file name
Size - same file size
Name/Date - same file name and date
Name/Size/Date - same file name, date and size
If searching for exact binary duplicate files, use the CRC option. This option first will sort the files by ascending file size and then compare each file in order with the next file using a 32-bit CRC comparison.
Once the comparison criteria is selected, the function will start. Progress
is reported on the pushbutton at the bottom of the window with the pushbutton
label changing to;
Pushing this button will abort the function. The two numbers [xxx - xxx] are the files processed and the duplicates found.
The window title bar changes to a magenta color when the function completes finding all duplicate files in the window. The directory of the cursored file is shown in the title bar and is also highlighted in the directory tree in Multiple Directories moding.
Exact matches are left in the window and all others are removed.
When using any of the five possible comparison criteria, keep in mind that the processing is based on a comparison of the displayed files. If a more stringent comparison criteria is used, such as the same 'Name/Date' vice 'Name', using the less stringent criteria afterwards with the remaining files will have no effect.
After the window shows only duplicate files, it's up to the user to decide what to do with them. Use the CRC file compare option Compare->Binary Compare (Shift+?) to determine if any two selected files at exactly the same. See Binary compare.
You may Select All and then File List->Save File List to save the list of duplicate files, either to the printer or disk.