Duplicate Detection

OffShoot will automatically detect duplicates when copying data into an existing folder structure. A file will not be copied when all of these conditions are met:

• A file with an identical name exists in the folder where the copy will end up

• That file has the same file size

• That file has the same modification date

When a file with an identical name already exists on the destination path, but has a different byte size and/or modification date, it will be copied using a counter following Finder and Explorer's duplicate naming conventions: B002C006_180327_R1ZA.mov becomes B002C006_180327_R1ZA 2.mov.

Skip the modification date check

In some workflows, duplicate detection can’t rely on a file’s modification date. In that case, you can skip the modification date check.

macOS

Requires OffShoot 26.1.2 or newer.

1. Open Terminal.

2. Paste the command below, then press Return:

   defaults write nl.syncfactory.Hedge.Mac SFIDefaultsSkipDuplicateDetectModificationDateCheck -bool true

To undo this change:

1. Open Terminal.

2. Paste the command below, then press Return:

   defaults delete nl.syncfactory.Hedge.Mac SFIDefaultsSkipDuplicateDetectModificationDateCheck

Windows

Requires OffShoot 26.2 or newer.

1. Open PowerShell.

2. Paste the command below, then press Return:

   New-Item -Path "HKCU:\Software\Hedge" -Force | Out-Null
   
   New-ItemProperty `
     -Path "HKCU:\Software\Hedge" `
     -Name "SkipDuplicateDetectModificationDateCheck" `
     -Value 1 `
     -PropertyType DWord `
     -Force

To undo this change:

1. Open PowerShell.

2. Paste the command below, then press Return:

   Remove-ItemProperty `
     -Path "HKCU:\Software\Hedge" `
     -Name "SkipDuplicateDetectModificationDateCheck"

Logging

Skipped files will be logged in the Transfer Log, under the section:

-- Skipped files (already on destination) --

Duplicates that do not match all criteria are logged as such:

-- Transferred files -- #1: B002C006_180327_R1ZA.mov path: XDROOT/CLIPS/B002C006_180327_R1ZA 2.mov

Finding duplicates without copying

If an identical file exists in a different folder on your destination, the source file will be copied. If you are looking for a way to find duplicates on an existing drive, have a look at Duplicate Detective or Gemini.