Utilities to Compare RAR Archive

RAR is an archive file format that supports file spanning, error recovery, and data compression. Developed by Eugene Roshal, RAR actually refers to Roshal Archive, and is a proprietary standard owned currently by win.rar GmbH. Data compression is one of the main reasons why RAR and other archive file formats are used – compressing the data saves on bandwidth and storage space. Archive files are also handy to collect various related files into one package. Archive files are so widespread and commonly used that apart from archive creators and extractors, there are also utilities to compare RAR archive with another.

File spanning refers to RAR’s ability to split a single archive into many smaller files. This is very useful when storing large files on small volumes or when transmitting a large amount of data through networks. This allows big files, for example videos or programs, to be downloaded by users in smaller chunks. This feature is helpful for data transfer over channels with limited bandwidth.

Error recovery, on the other hand, refers to a RAR archive’s ability to be recovered even with errors due to transmission, for example. This usually requires the creation of a .rev recovery volume set. With the appropriate .rev file available, corrupted or otherwise erroneous .rar files may be restored, and the data contained in them accessed. This makes it possible to recover from errors due to less than ideal transmission channels or storage devices. Even without a .rev file, such measures as cyclic redundancy check and hash checks may be employed to verify the integrity of a RAR archive. However, repair may be more difficult, if not impossible, without a .rev file.

Data compression, of course, refers to RARs reducing the overall disk space or file size of its contents. For these three features, many large files are distributed in RAR (or other similar archive formats) archives.

Comparing RAR archives is usually done to ensure that two archives are identical. For instance, two copies of the archive may have undergone different sets of changes. Using a comparison utility, these changes may be viewed and merged, if so desired. Most utilities will be able to compare the file and folder structure within two separate RAR archives, displaying the similarities and differences. This makes it easier for the human user to pinpoint where exactly the differences lie and to take the appropriate action.

These archive comparison utilities also allow the merging of changes from one archive file to another. This usually consists of copying over files or subfolders present in one RAR file over to another RAR file where those are missing. This is useful for synchronizing two archives in different locations, such as on a hard drive and on removable media, such as flash drives.

Utilities to compare RAR archive to another are indeed very useful for a variety of reasons. RAR archives are commonly used because they reduce file size and also offer some protection against incidental errors in storage or transmission. With comparison utilities, RAR files become even easier to handle and manage.