WinRAR is a
32-bit and
64-bit compressor/
decompressor for
Windows. It provides support for a number of different formats, including
RAR,
ZIP,
ACE,
ARJ,
CAB,
LZH,
TAR,
GZip,
7Zip and
UUE. It allows for the creation of
RAR and
ZIP archives, and both can be made into self-extracting or password protected archives.
One of the unique features that gives WinRAR an advantage over the traditional Zip format is its ability to automatically split files into pre-determined file sizes which is helpful when trying to transport files by
floppy disk or
zip disk. For example, if there were a 150 MB file, WinRAR could be set to archive the file into 100 MB chunks, and it would create the files
file.rar (100MB) &
file.r00 (50 MB). One of the best features about this that I had previously been hesitant to mention is that on
usenet servers messages cannot usually be above a certain size, and certainly when downloading a
CD image one does not want to download a single 650 MB file, thus; WinRAR allows the file(s) to be broken into much smaller and more easily managed files. Would you rather have a 650 MB download die when it has completed 647.5 MB, or have the 259th part of a 260 part series of 2.5 MB files die during download?
In addition, WinRAR has the ability to create a
solid archive, which further compresses data by treating the data inside the archive as a continuous file even if there is more than one file present. WinRAR can also encode information about the creator of the archive, the last update time, and the true archive name and can use a special multimedia compression
algorithm that can compress
digital audio up to 30% more than standard compression.
Another feature of WinRAR is its ability to place a recovery record in the archive, so that if data is damaged in the archive it can be repaired. Taken from the WinRAR help file:
The recovery record contains up to 4096 recovery sectors. If data are damaged continuously then each recovery sector is able to recover 512 bytes of damaged information. This value may be lower in cases of multiple damage.
The number of sectors may be specified directly in the "rrN" command or "-rrN" switch (N = 1, 2 .. 4096). If it is not specified by the user, it will be selected automatically according to the archive size: a size of the recovery information will be about 1.2% of the total archive size, usually allowing the recovery of up to 0.7% of the total archive size of continuously damaged data.