ARJ
From Just Solve the File Format Problem
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| − | |1 || compressed most ||rowspan="3"| [[LZ77 with Huffman coding|LZ77+Huffman]]. | + | |1 || compressed most ||rowspan="3"| [[LZ77 with Huffman coding|LZ77+Huffman]]. For decompression purposes, these are all more-or-less compatible with [[LHA]]'s "lh6" method. |
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Revision as of 14:10, 30 January 2021
ARJ is a compressed archive format, and associated software. It was developed by Robert Jung.
ARJ was one of the leading compression tools during the 1990s. While it was a bit slower than PKZIP, it sported many more options, some of which were unique during that time (archives over multiple disks/volumes, fine-tuning of the compression algorithms used based on the data that was being compressed, recovery records to recover from simple transmission errors, etc.).
Contents |
See also
Compression methods
| ID | Name | Description |
|---|---|---|
| 0 | stored | No compression |
| 1 | compressed most | LZ77+Huffman. For decompression purposes, these are all more-or-less compatible with LHA's "lh6" method. |
| 2 | ... | |
| 3 | ... | |
| 4 | compressed fastest | LZ77 |
| 8 | no data, no CRC | (whatever that means) |
| 9 | no data | (whatever that means) |
Identification
An ARJ archive starts with signature bytes 0x60 0xea.
The full identification algorithm used by the ARJ software is given in its technical documentation.
Specifications
- The ARJ/UNARJ distributions include detailed format information, in a file named TECHNOTE.TXT or similar.
- A copy of the 2001-09 version (with an addendum of some sort)
- The ARJ Archive File Format, from fileformat.info and Corion.net
Software
- Official homepage of ARJ software
- ARJ - Official compression/decompression software for DOS
- ARJ32 - Official compression/decompression software for Windows console
- UNARJ - Official software, decompression only
- 7-Zip
- Open-source ARJ
- Konvertor
Ed. note: Some newer versions of ARJ/ARJ32 have a long delay (2 minutes?) when you run them.
Sample files
- http://cd.textfiles.com/20mnn/HPTEXT/PHRACK/
- The Silver Collection CDs have many ARJ files
- http://cd.textfiles.com/goldmedal/
