|
Lrzip
rzip is a huge-scale data compression computer program designed around initial LZ77-style string matching on a 900 MB dictionary window, followed by bzip2-based Burrows–Wheeler transform and entropy coding ( Huffman) on 900 kB output chunks. Compression algorithm rzip operates in two stages. The first stage finds and encodes large chunks of duplicated data over potentially very long distances (900 MB) in the input file. The second stage uses a standard compression algorithm ( bzip2) to compress the output of the first stage. It is quite common these days to need to compress files that contain long distance redundancies. For example, when compressing a set of home directories several users might have copies of the same file, or of quite similar files. It is also common to have a single file that contains large duplicated chunks over long distances, such as PDF files containing repeated copies of the same image. Most compression programs won't be able to take ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tar (computing)
In computing, tar is a computer software utility for collecting many files into one archive file, often referred to as a tarball, for distribution or backup purposes. The name is derived from "tape archive", as it was originally developed to write data to sequential I/O devices with no file system of their own. The archive data sets created by tar contain various file system parameters, such as name, timestamps, ownership, file-access permissions, and directory organization. POSIX abandoned ''tar'' in favor of '' pax'', yet ''tar'' sees continued widespread use. History The command-line utility was first introduced in the Version 7 Unix in January 1979, replacing the tp program (which in turn replaced "tap"). The file structure to store this information was standardized in POSIX.1-1988 and later POSIX.1-2001, and became a format supported by most modern file archiving systems. The tar command was abandoned in POSIX.1-2001 in favor of pax command, which was to support ust ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C (programming Language)
C (''pronounced like the letter c'') is a General-purpose language, general-purpose computer programming language. It was created in the 1970s by Dennis Ritchie, and remains very widely used and influential. By design, C's features cleanly reflect the capabilities of the targeted CPUs. It has found lasting use in operating systems, device drivers, protocol stacks, though decreasingly for application software. C is commonly used on computer architectures that range from the largest supercomputers to the smallest microcontrollers and embedded systems. A successor to the programming language B (programming language), B, C was originally developed at Bell Labs by Ritchie between 1972 and 1973 to construct utilities running on Unix. It was applied to re-implementing the kernel of the Unix operating system. During the 1980s, C gradually gained popularity. It has become one of the measuring programming language popularity, most widely used programming languages, with C compilers avail ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lempel–Ziv–Oberhumer
Lempel–Ziv–Oberhumer (LZO) is a lossless data compression algorithm that is focused on decompression speed. Design The original "lzop" implementation, released in 1996, was developed by Markus Franz Xaver Johannes Oberhumer, based on earlier algorithms by Abraham Lempel and Jacob Ziv. The LZO library implements a number of algorithms with the following characteristics: * Higher compression speed compared to DEFLATE compression * Very fast decompression * Requires an additional buffer during compression (of size 8 kB or 64 kB, depending on compression level) * Requires no additional memory for decompression other than the source and destination buffers * Allows the user to adjust the balance between compression ratio and compression speed, without affecting the speed of decompression LZO supports overlapping compression and in-place decompression. As a block compression algorithm, it compresses and decompresses blocks of data. Block size must be the same for compres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of File Archivers
The following tables compare general and technical information for a number of file archivers. Please see the individual products' articles for further information. They are neither all-inclusive nor are some entries necessarily up to date. Unless otherwise specified in the footnotes section, comparisons are based on the stable versions—''without'' add-ons, extensions or external programs. Archivers ''Note: Archivers with names cell background highlighted in purple are no longer in development.'' General information Basic general information about the archivers. Notes: Operating system support The operating systems the archivers can run on without emulation or compatibility layer. Ubuntu's own GUI ''Archive manager,'' for example, can open and create many archive formats (including Rar archives) even to the extent of splitting into parts and encryption and ability to be read by the ''native program''. This is presumably a "compatibility layer." Notes: # A separate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comparison Of Archive Formats
This is a list of file formats used by archivers and compressors used to create archive files. Archiving only Compression only Archiving and compression Data recovery Comparison Containers and compression Notes While the original tar format uses the ASCII character encoding, current implementations use the UTF-8 (Unicode) encoding, which is backwards compatible with ASCII. Supports the external Parchive program (par2). From 3.20 release RAR can store modification, creation and last access time with the precision up to 0.0000001 second (= 0.1 µs) The PAQ family (with its lighter weight derivative LPAQ) went through many revisions, each revision suggested its own extension. For example: ".paq9a". WIM can store the ciphertext of encrypted files on an NTFS volume, but such files can only by decrypted if an administrator extracts the file to an NTFS volume, and the decryption key is available (typically from the file's original owner on the same Windows installa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Archive Formats
This is a list of file formats used by archivers and compressors used to create archive files. Archiving only Compression only Archiving and compression Data recovery Comparison Containers and compression Notes While the original tar format uses the ASCII character encoding, current implementations use the UTF-8 (Unicode) encoding, which is backwards compatible with ASCII. Supports the external Parchive program (par2). From 3.20 release RAR can store modification, creation and last access time with the precision up to 0.0000001 second (= 0.1 µs) The PAQ family (with its lighter weight derivative LPAQ) went through many revisions, each revision suggested its own extension. For example: ".paq9a". WIM can store the ciphertext of encrypted files on an NTFS volume, but such files can only by decrypted if an administrator extracts the file to an NTFS volume, and the decryption key is available (typically from the file's original owner on the same Windows installation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FreeArc
FreeArc is a free and open-source high-performance file archiver developed by Bulat Ziganshin. The project is considered abandonware as no information has been released by developers since 2016 and the official website is down. A "FreeArc Next" version is under development, with version FA 0.11 released in October 2016. The "Next" version supports 32- and 64-bit Windows and Linux and includes Zstandard support. Algorithms FreeArc uses LZMA, prediction by partial matching, TrueAudio, Tornado and GRzip algorithms with automatic switching by file type. Additionally, it uses filters to further improve compression, including REP (finds repetitions at separations up to 1gb), DICT (dictionary replacements for text), DELTA (improves compression of tables in binary data), BCJ (executables preproccesor) and LZP (removes repetitions in text). Benchmarks Archive size In 2010 Tom's Hardware benchmarks comparing it to the other popular archivers, FreeArc narrowly outperformed WinZip, 7-Zi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CPU Core
A central processing unit (CPU), also called a central processor, main processor or just processor, is the electronic circuitry that executes instructions comprising a computer program. The CPU performs basic arithmetic, logic, controlling, and input/output (I/O) operations specified by the instructions in the program. This contrasts with external components such as main memory and I/O circuitry, and specialized processors such as graphics processing units (GPUs). The form, design, and implementation of CPUs have changed over time, but their fundamental operation remains almost unchanged. Principal components of a CPU include the arithmetic–logic unit (ALU) that performs arithmetic and logic operations, processor registers that supply operands to the ALU and store the results of ALU operations, and a control unit that orchestrates the fetching (from memory), decoding and execution (of instructions) by directing the coordinated operations of the ALU, registers and other compo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Advanced Encryption Standard
The Advanced Encryption Standard (AES), also known by its original name Rijndael (), is a specification for the encryption of electronic data established by the U.S. National Institute of Standards and Technology (NIST) in 2001. AES is a variant of the Rijndael block cipher developed by two Belgian cryptographers, Joan Daemen and Vincent Rijmen, who submitted a proposal to NIST during the AES selection process. Rijndael is a family of ciphers with different key and block sizes. For AES, NIST selected three members of the Rijndael family, each with a block size of 128 bits, but three different key lengths: 128, 192 and 256 bits. AES has been adopted by the U.S. government. It supersedes the Data Encryption Standard (DES), which was published in 1977. The algorithm described by AES is a symmetric-key algorithm, meaning the same key is used for both encrypting and decrypting the data. In the United States, AES was announced by the NIST as U.S. FIPS PUB 197 (FIPS 197) on Novemb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ZPAQ
ZPAQ is an open source command line archiver for Windows and Linux. It uses a journaling or append-only format which can be rolled back to an earlier state to retrieve older versions of files and directories. It supports fast incremental update by adding only files whose last-modified date has changed since the previous update. It compresses using deduplication and several algorithms (LZ77, BWT, and context mixing) depending on the data type and the selected compression level. To preserve forward and backward compatibility between versions as the compression algorithm is improved, it stores the decompression algorithm in the archive. The ZPAQ source code includes a public domain API, libzpaq, which provides compression and decompression services to C++ applications. The format is believed to be unencumbered by patent A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited per ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
_Round_Function.png "Click for more on -> Advanced Encryption Standard")