CheckCopy is a free command line utility that lets you compare folders and verify their files. It generates a single file that contains the CRC hashes of each file. This small file can then be used to either check/compare another folder hierarchy, or be used as an integrity check of the same folder hierarchy.
More info at the CrcCheckCopy website
- Compare folders.
- Compare file contents and verify them.
- Finds zero sized files.
- Finds duplicate files (since ver 2.2), even if they have different filenames and different extensions and are stored in completely different folders.
- Creates the CRC hash of each file (like a digital signature of the file).
- Creates a single file with the CRC hashes of every file. This file can be used to compare another folder, or to verify the same folder in the future: to make sure that no file was deleted in the meantime or has been altered. In this way, it adds a digital signature to the whole folder structure and its files.
- No need for concurrent access to the two folders that must be compared.
- No need for network connection or internet bandwidth when comparing folders on remote computers: Only the CRC signatures file needs to be transferred between them. The program will run locally.
- Ensure integrity of backups: You can store the CRC file together with the backup and you will be able to validate the integrity of the files and their contents at any time in the future.
- Cross platform (Windows, MacOS)
- Portable app. No installation needed.
- Continue the comparison on another Operating System: Lets you compare a folder structure on Windows with its backup copy on a Mac/Macbook.
- Creates a report file with the comparison results, the zero sized files and the duplicate files found.
- The report is in plain text so you can furher process or parse it with other tools, e.g. import in to excel.
The comparison is completed in two steps.
Step1 (Source scanning): reads all files of the source folder and creates in the current working directory one CRC stamps file ("CRCstamps.txt").
Syntax:
CrcCheckCopy /scan <SourceFolder>or using the short version of the switch
CrcCheckCopy /s <SourceFolder>If the path contains spaces, then include the path in quotes, e.g.
CrcCheckCopy /scan "C:\folder with spaces"Step2 (Verification): uses the CRC stamps file of Step1 to verify all the files at the destination folder.
Syntax:
CrcCheckCopy /verify <DestinationFolder>or using the short version of the switch
CrcCheckCopy /v <DestinationFolder>If the destination folder has additional files that do not exist in the source folder, then these files will not be checked nor be reported.
How does it compare two folders
- Windows XP and later, 32/64 bit
- MacOS