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91-463: Differing from traditional package managers , Guix (like Nix) utilizes a purely functional deployment model where software is installed into unique directories generated through cryptographic hashes . All dependencies for each software are included within each hash. This solves the problem of dependency hell , allowing multiple versions of the same software to coexist which makes packages portable and reproducible . Performing scientific computations in

182-991: A backend . Yum extends the functionality of the backend by adding features such as simple configuration for maintaining a network of systems. As another example, the Synaptic Package Manager provides a graphical user interface by using the Advanced Packaging Tool (apt) library, which, in turn, relies on dpkg for core functionality. Alien is a program that converts between different Linux package formats , supporting conversion between Linux Standard Base (LSB) compliant .rpm packages, .deb , Stampede (.slp), Solaris (.pkg) and Slackware ( .tgz , .txz , .tbz, .tlz) packages. In mobile operating systems, Google Play consumes Android application package (APK) package format while Microsoft Store uses APPX and XAP formats. (Both Google Play and Microsoft Store have eponymous package managers.) By

273-618: A Guix setup has been proposed as a promising response to the replication crisis . The development of GNU Guix is intertwined with the GNU Guix System , an installable operating system distribution using the Linux-libre kernel and GNU Shepherd init system. Guix packages are defined through functional Guile Scheme APIs specifically designed for package management. Dependencies are tracked directly in this language through special values called "derivations" which are evaluated by

364-425: A binary executable package on the same or remote computer. Later a package manager typically running on some other computer downloads those pre-built binary executable packages over the internet and installs them. However, both kinds of tools have many commonalities: A few tools, such as Maak and A-A-P , are designed to handle both building and deployment, and can be used as either a build automation utility or as

455-558: A challenge colloquially known as " dependency hell ". On Microsoft Windows systems, this is also called " DLL hell " when working with dynamically linked libraries. Modern package managers have mostly solved these problems, by allowing parallel installation of multiple versions of a library (e.g. OPENSTEP 's Framework system), a dependency of any kind (e.g. slots in Gentoo Portage ), and even of packages compiled with different compiler versions (e.g. dynamic libraries built by

546-478: A core set of services are provided with the basic Guix System, arbitrary new services can be flexibly declared, and through Guile's object system , GOOPS, existing services can be redefined at the user's discretion by asking the Shepherd to dynamically rewrite services in specified ways on instantiation. GNU Shepherd was originally designed to work with GNU Hurd , and was later adopted by Guix System. Similar to

637-487: A form of composability whereby services are designed to be layered onto other services, augmenting them with more elaborate or specialized behaviours as desired. This expresses the instantiation-based dependency relationships found in many modern init systems, making the system modular, but also allows services to interact variadically with other services in arbitrary ways, e.g. a service that extends two other services, requiring only one to be present, but readily extending

728-614: A large extent translatable, as most package managers offer similar functions. The Arch Linux Pacman/Rosetta wiki offers an extensive overview. Package managers like dpkg have existed as early as 1994. Linux distributions oriented to binary packages rely heavily on package management systems as their primary means of managing and maintaining software. Mobile operating systems such as Android (Linux-based), iOS ( Unix-based ), and Windows Phone rely almost exclusively on their respective vendors' app stores and thus use their own dedicated package management systems. A package manager

819-449: A large number of computers. This kind of pre-configured installation is also supported by dpkg. To give users more control over the kinds of software that they are allowing to be installed on their system (and sometimes due to legal or convenience reasons on the distributors' side), software is often downloaded from a number of software repositories . When a user interacts with the package management software to bring about an upgrade, it

910-623: A necessary but not sufficient condition for scientific workflows to be reproducible, as it is necessary to incorporate data collection and processing into the workflow, if this is added as part of the Guix recipe, it could satisfy the strict reproducibility requirements. The project was started in June 2012 by Ludovic Courtès, one of the GNU Guile hackers. The GNU Project announced in November 2012

1001-566: A new empty directory and extract the archive into it—or avoid the tar file entirely. Most graphical tools can display the contents of the archive before extracting them. Vim can open tar archives and display their contents. GNU Emacs is also able to open a tar archive and display its contents in a dired buffer. The tar format was designed without a centralized index or table of content for files and their properties for streaming to tape backup devices. The archive must be read sequentially to list or extract files. For large tar archives, this causes

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1092-455: A new generation will be built. E.g. the profile of a user who only installed GNU Hello contains links to the store item which holds the version of hello installed with the currently used guix. E.g. on version c087a90e06d7b9451f802323e24deb1862a21e0f of guix, this corresponds to the following item: /gnu/store/md2plii4g5sk66wg9cgwc964l3xwhrm9-hello-2.10 (built from the recipe above). In addition to symlinks, each profile guix builds also contains

1183-468: A package manager or both. App stores can also be considered application-level package managers (without the ability to install all levels of programs ). Unlike traditional package managers, app stores are designed to enable payment for the software itself (instead of for software development), and may only offer monolithic packages with no dependencies or dependency resolution. They are usually extremely limited in their management functionality, due to

1274-402: A performance penalty, making tar archives unsuitable for situations that often require random access to individual files. With a well-formed tar file stored on a seekable (i.e. allows efficient random reads) medium, the tar program can still relatively quickly (in linear time relative to file count) look for a file by skipping file reads according to the "size" field in the file headers. This

1365-416: A specified date. Basic options: Create an archive file archive.tar from the file README.txt and directory src : Extract contents for the archive.tar into the current directory: Create an archive file archive.tar.gz from the file README.txt and directory src and compress it with gzip  : Extract contents for the archive.tar.gz into the current directory: A tarpipe

1456-485: A strong focus on simplification over power or emergence , and common in commercial operating systems and locked-down “smart” devices. Package managers also often have only human-reviewed code. Many app stores, such and Google Play and Apple's App Store, screen apps mostly using automated tools only; malware with defeat devices can pass these tests, by detecting when the software is being automatically tested and delaying malicious activity. There are, however, exceptions;

1547-453: A union of all the info-manuals, man-pages, icons, fonts, etc. so that the user can browse documentation and have access to all the icons and fonts installed. The default symlinks to profile generations are stored under /var/guix in the filesystem. The user can create any number of profiles by invoking guix package -p PROFILE-NAME COMMAND . A new directory with the profile-name as well as profile-generation-symlinks will then be created in

1638-406: A user has only a very old tar available, which does not feature those security measures, these problems can be mitigated by first examining a tar file using the command tar tf archive.tar , which lists the contents and allows to exclude problematic files afterwards. These commands do not extract any files, but display the names of all files in the archive. If any are problematic, the user can create

1729-630: Is CheckInstall , and for recipe-based systems such as Gentoo Linux and hybrid systems such as Arch Linux , it is possible to write a recipe first, which then ensures that the package fits into the local package database. Particularly troublesome with software upgrades are upgrades of configuration files. Since package managers, at least on Unix systems, originated as extensions of file archiving utilities , they can usually only either overwrite or retain configuration files, rather than applying rules to them. There are exceptions to this that usually apply to kernel configuration (which, if broken, will render

1820-629: 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, such as devices that use magnetic tape . 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. The command-line utility

1911-406: Is a software tool designed to optimize the download and storage of binary files, artifacts and packages used and produced in the software development process . These package managers aim to standardize the way enterprises treat all package types. They give users the ability to apply security and compliance metrics across all artifact types. Universal package managers have been referred to as being at

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2002-521: Is accomplished by a combination of Guix's functional package manager , which treats each package and system configuration as an immutable and reproducible entity, and the generation system which maintains a history of system configurations as "generations." These generations are stored as separate profiles, which allow you to roll back to any previous configuration, and you can see these generations with guix package --list-generations . Jesse Smith from DistroWatch Weekly reviewed GNU Guix System 0.15.0 (at

2093-432: Is customary to present the user with the list of actions to be executed (usually the list of packages to be upgraded, and possibly giving the old and new version numbers), and allow the user to either accept the upgrade in bulk, or select individual packages for upgrades. Many package managers can be configured to never upgrade certain packages, or to upgrade them only when critical vulnerabilities or instabilities are found in

2184-452: Is designed so that all implementations able to read the UStar format will be able to read the pax format as well. The only exceptions are files that make use of extended features, such as longer file names. For compatibility, these are encoded in the tar files as special x or g type files, typically under a PaxHeaders.XXXX directory. A pax-supporting implementation would make use of

2275-609: Is in the field of reproducible scientific workflows, mainly in High Performance Computing . In this way, Guix would offer a way to share a reproducible computational environment, i.e. Guix using a recipe for the particular scientific software/environment would provide all the information needed to uniquely describe the dependency tree to build and run that software. This would not be easy to achieve, for example, in other mixed systems with several package managers for each programming language. However, this only provides

2366-482: Is in use. The UStar format allows for longer file names and stores additional information about each file. The maximum filename size is 256, but it is split among a preceding path "filename prefix" and the filename itself, so can be much less. The type flag field can have the following values: POSIX.1-1988 vendor specific extensions using link flag values 'A'–'Z' partially have a different meaning with different vendors and thus are seen as outdated and replaced by

2457-517: Is known as extended tar format or pax format. The new tar format allows users to add any type of vendor-tagged vendor-specific enhancements. The following tags are defined by the POSIX standard: In 2001, the Star program became the first tar to support the new format. In 2004, GNU tar supported the new format, though it does not write it as its default output from the tar program yet. The pax format

2548-414: Is leaner and conforms to practices like don't repeat yourself and single source of truth . If the user chooses to build everything from source, even larger storage space and bandwidth is required. Inherited from the design of Nix, most of the content of the package manager is kept in a directory /gnu/store where only the Guix daemon has write-access. This is achieved via specialised bind mounts, where

2639-418: Is often called an "install manager", which can lead to a confusion between package managers and installers . The differences include: Most software configuration management systems treat building software and deploying software as separate, independent steps. A build automation utility typically takes human-readable source code files already on a computer, and automates the process of converting them into

2730-461: Is older versions of GNU tar, when running on the MASSCOMP RTU (Real Time Unix) operating system, which supported an O_CTG flag to the open() function to request a contiguous file; however, that support was removed from GNU tar version 1.24 onwards. In 1997, Sun proposed a method for adding extensions to the tar format. This method was later accepted for the POSIX.1-2001 standard. This format

2821-464: Is preceded by a 512-byte header record. The file data is written unaltered except that its length is rounded up to a multiple of 512 bytes. The original tar implementation did not care about the contents of the padding bytes, and left the buffer data unaltered, but most modern tar implementations fill the extra space with zeros. The end of an archive is marked by at least two consecutive zero-filled records. (The origin of tar's record size appears to be

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2912-573: Is present (gcc, guile, etc.) and registered as a root in the current directory (by symlinking to the items in the store). Guix pack enables the user to bundle together store items and output them as either a docker binary image, a relocatable tarball , a debian package file or a squashfs binary. Guix graph enables the user to view different graphs of the packages and their dependencies. Guix allows you to specify additional channels for package definitions. This feature can also used to install non-free software and firmware that cannot be packaged in

3003-463: Is that free and open source software systems permit third-party packages to also be installed and upgraded through the same mechanism, whereas the package managers of Mac OS X and Windows will only upgrade software provided by Apple and Microsoft, respectively (with the exception of some third party drivers in Windows). The ability to continuously upgrade third-party software is typically added by adding

3094-453: Is the basis for option -n in GNU tar. When a tar file is compressed whole, the compression format, being usually non-seekable, prevents this optimization from being done. A number of "indexed" compressors, which are aware of the tar format, can restore this feature for compressed files. To maintain seekability, tar files must be also concatenated properly, by removing the trailing zero block at

3185-579: Is the method of creating an archive on the standard output file of the tar utility and piping it to another tar process on its standard input , working in another directory, where it is unpacked. This process copies an entire source directory tree including all special files, for example: The tar format continues to be used extensively for open-source software distribution . *NIX-distributions use it in various source- and binary-package distribution mechanisms, with most software source code made available in compressed tar archives. The original tar format

3276-557: Is the number of blocks per record. The default is 20, producing 10  KiB records. There are multiple tar file formats, including historical and current ones. Two tar formats are codified in POSIX: ustar and pax . Not codified but still in current use is the GNU tar format. A tar archive consists of a series of file objects, hence the popular term tarball , referencing how a tarball collects objects of all kinds that stick to its surface. Each file object includes any file data, and

3367-426: Is to allow users to manage the software dependency on data, such as machine learning models for data-driven applications. They are useful to publish, locate, and install data packages. A typical example of a data dependency management frameworks are Hugging Face, KBox, among others. Ian Murdock had commented that package management is "the single biggest advancement Linux has brought to the industry", that it blurs

3458-463: Is written and configurable in Guile . It supplies user-space functionality asynchronously as services, which under Shepherd are generic functions and object data types which it uses to extend the base operating system in a defined way. In contrast to systemd , a userspace shepherd process runs as the user. Central to the Shepherd model of user space initialization is the concept of the extension ,

3549-505: The guix environment command, which installs the dependencies of a package by default, as it was considered more intuitive for the command to install the specified packages by default and only install development dependencies with a flag. If you want a persistent gc-rooted environment that is not garbage collected on the next run of guix gc you can create a root: E.g. running guix shell --root=hello-root --development hello enters an environment where everything needed to compile guix

3640-477: The Glasgow Haskell Compiler , where a stable ABI does not exist), in order to enable other packages to specify which version they were linked or even installed against. System administrators may install and maintain software using tools other than package management software. For example, a local administrator may download unpackaged source code, compile it, and install it. This may cause

3731-453: The URL of the corresponding repository to the package management's configuration file. Beside the system-level application managers, there are some add-on package managers for operating systems with limited capabilities and for programming languages in which developers need the latest libraries . Unlike system-level package managers, application-level package managers focus on a small part of

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3822-465: The npm package database, for instance, relies entirely on post-publication review of its code, while the Debian package database has an extensive human review process before any package goes into the main stable database. The XZ Utils backdoor used years of trust-building to insert a backdoor, which was nonetheless caught while in the testing database. Also known as binary repository manager , it

3913-502: The "system-service," which is responsible for early phases of boot and init, as its root, and all subsequently initialized services as extensions to system-service functionality, either directly or transitively over other services. It is intended to be highly programmable by the system administrator using Guile, but it can also be used to manage per-user profiles of unprivileged daemons and services. Its services and configuration are stored uniformly as object-oriented Scheme code, and while

4004-410: The 1.4.0 release. Package manager A package manager or package-management system is a collection of software tools that automates the process of installing, upgrading, configuring, and removing computer programs for a computer in a consistent manner. A package manager deals with packages , distributions of software and data in archive files . Packages contain metadata , such as

4095-483: The 100 characters are stored in @LongLink entries that would be seen as ordinary files by TAR utilities unaware of this feature. Similarly, the PAX format uses PaxHeaders entries. Many older tar implementations do not record nor restore extended attributes (xattrs) or access-control lists (ACLs). In 2001, Star introduced support for ACLs and extended attributes, through its own tags for POSIX.1-2001 pax. bsdtar uses

4186-535: The 512-byte disk sectors used in the Version 7 Unix file system.) The final block of an archive is padded out to full length with zeros. The file header record contains metadata about a file. To ensure portability across different architectures with different byte orderings , the information in the header record is encoded in ASCII . Thus if all the files in an archive are ASCII text files, and have ASCII names, then

4277-463: The Guix daemon lazily . Guix keeps track of these references automatically so that installed packages can be garbage collected when no other package depends on them - at the cost of greater storage requirements, all upgrades in Guix are guaranteed to be both atomic and can be rolled back. The roll-back feature of Guix is inherited from the design of Nix and is rarely found in other operating systems , since it requires an unorthodox approach to how

4368-410: The POSIX.1-2001 extensions that also include a vendor tag. Type '7' (Contiguous file) is formally marked as reserved in the POSIX standard, but was meant to indicate files which ought to be contiguously allocated on disk. Few operating systems support creating such files explicitly, and hence most TAR programs do not support them, and will treat type 7 files as if they were type 0 (regular). An exception

4459-468: The Store as a file system is mounted read only , prohibiting interference even from the root user, while the Guix daemon remounts the Store as read/writable in its own private namespace. Guix talks with this daemon to build things or fetch substitutes which are all kept in the store. Users are discouraged from ever manually touching the store by re-mounting it as writable since this defeats the whole purpose of

4550-411: The archive is essentially an ASCII text file (containing many NUL characters ). The fields defined by the original Unix tar format are listed in the table below. The link indicator/file type table includes some modern extensions. When a field is unused it is filled with NUL bytes. The header uses 257 bytes, then is padded with NUL bytes to make it fill a 512 byte record. There is no "magic number" in

4641-538: The boundaries between operating system and applications, and that it makes it "easier to push new innovations [...] into the marketplace and [...] evolve the OS". There is also a conference for package manager developers known as PackagingCon. It was established in 2021 with the aim to understand different approaches to package management. Tar (computing) u s t a r \040 \040 \0  (for old GNU tar format) In computing , tar

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4732-482: The center of a DevOps toolchain . Each package manager relies on the format and metadata of the packages it can manage. That is, package managers need groups of files to be bundled for the specific package manager along with appropriate metadata, such as dependencies. Often, a core set of utilities manages the basic installation from these packages and multiple package managers use these utilities to provide additional functionality. For example, yum relies on rpm as

4823-436: The checksum both ways, and treat it as good if either the signed or unsigned sum matches the included checksum. Unix filesystems support multiple links (names) for the same file. If several such files appear in a tar archive, only the first one is archived as a normal file; the rest are archived as hard links, with the "name of linked file" field set to the first one's name. On extraction, such hard links should be recreated in

4914-480: The computer unusable after a restart). Problems can be caused if the format of configuration files changes; for instance, if the old configuration file does not explicitly disable new options that should be disabled. Some package managers, such as Debian 's dpkg , allow configuration during installation. In other situations, it is desirable to install packages with the default configuration and then overwrite this configuration, for instance, in headless installations to

5005-431: The current directory. Guix package enables instantaneous roll-back to a previous profile generation via changing the symlink to an earlier profile generation. Profiles are also stored in the store e.g. this item is a profile containing hello above: /gnu/store/b4wipjlsapvnijmbawl7sh76087vpl4n-profile (built and activated when running guix install hello ). Guix shell enables the user to easily enter an environment where all

5096-419: The design of Nix, all manipulation of store items is independent of each other, and the directories of the store begin with a base32-encoded hash of the source code of the derivation along with its inputs. Guix package uses profiles generations, which are a collection of symlinks to specific store items together comprising what the user has installed into the profile. Every time a package is installed or removed,

5187-508: The end of each file. Another issue with tar format is that it allows several (possibly different) files in archive to have identical paths and filenames. When extracting such archive, usually the latter version of a file overwrites the former. This can create a non-explicit (unobvious) tarbomb, which technically does not contain files with absolute paths or referring to parent directories, but still causes overwriting files outside current directory (for example, archive may contain two files with

5278-401: The file size, only 11 octal digits can be stored. This gives a maximum file size of 8 gibibytes on archived files. To overcome this limitation, in 2001 star introduced a base-256 coding that is indicated by setting the high-order bit of the leftmost byte of a numeric field. GNU-tar and BSD-tar followed this idea. Additionally, versions of tar from before the first POSIX standard from 1988 pad

5369-404: The file suffix .tar (e.g. somefile.tar ). A tar archive file contains uncompressed byte streams of the files which it contains. To achieve archive compression, a variety of compression programs are available, such as gzip , bzip2 , xz , lzip , lzma , zstd , or compress , which compress the entire tar archive. Typically, the compressed form of the archive receives a filename by appending

5460-477: The file system. Most modern tar programs read and write archives in the UStar ( Unix Standard TAR ) format, introduced by the POSIX IEEE P1003.1 standard from 1988. It introduced additional header fields. Older tar programs will ignore the extra information (possibly extracting partially named files), while newer programs will test for the presence of the "ustar" string to determine if the new format

5551-405: The first release of GNU Guix, a functional package manager based on Nix that provides, among other things, Guile Scheme APIs . On August 20, 2015, it was announced that Guix had been ported to GNU Hurd . The project has no fixed release schedule and has until now released approximately every 6 months. There are plans for an upcoming 1.5.0 release since there has been a 20 month gap since

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5642-488: The header, for file identification. Pre-POSIX.1-1988 (i.e. v7) tar header: The pre-POSIX.1-1988 Link indicator field can have the following values: Some pre-POSIX.1-1988 tar implementations indicated a directory by having a trailing slash (/) in the name. Numeric values are encoded in octal numbers using ASCII digits, with leading zeroes. For historical reasons, a final NUL or space character should also be used. Thus although there are 12 bytes reserved for storing

5733-421: The implementations below). The history of tar is a story of incompatibilities, known as the "tar wars". Most tar implementations can also read and create cpio and pax (the latter actually is a tar -format with POSIX -2001-extensions). Key implementations in order of origin: Additionally, most pax and cpio implementations can read and create multiple types of tar files. tar archive files usually have

5824-410: The information, while non-supporting ones like 7-Zip would process them as additional files. Besides creating and extracting archives, the functionality of the various archival utilities varies. For example, implementations might automatically detect the format of compressed TAR archives for extraction so the user does not have to specify it, and let the user limit adding files to those modified after

5915-466: The main project. GNU Guix System or Guix System (previously known as GuixSD ) is a rolling release , free and open source Linux distribution built around Guix, similar to how NixOS is built around Nix . It enables a declarative operating system configuration and allows system upgrades that the user can rollback . It uses the GNU Shepherd init system and the Linux-libre kernel, with

6006-644: The nature of free and open source software , packages under similar and compatible licenses are available for use on a number of operating systems. These packages can be combined and distributed using configurable and internally complex packaging systems to handle many permutations of software and manage version-specific dependencies and conflicts. Some packaging systems of free and open source software are also themselves released as free and open source software. One typical difference between package management in proprietary operating systems, such as Mac OS X and Windows, and those in free and open source software, such as Linux,

6097-447: The necessary packages for development of software are present without clogging up the user's default profile with dependencies for multiple projects. E.g. running guix shell --development hello enters a throw-away environment where everything needed to compile hello on guix is present (gcc, guile, etc.). Without the --development flag, only the package hello would be installed and not its build-dependencies. This supplants

6188-454: The need for manual installs and updates. This can be particularly useful for large enterprises whose operating systems typically consist of hundreds or even tens of thousands of distinct software packages. An early package manager was SMIT (and its backend installp) from IBM AIX . SMIT was introduced with AIX 3.0 in 1989. Early package managers, from around 1994, had no automatic dependency resolution but could already drastically simplify

6279-444: The previous version, as defined by the packager of the software. This process is sometimes called version pinning . For instance: Some of the more advanced package management features offer "cascading package removal", in which all packages that depend on the target package and all packages that only the target package depends on, are also removed. Although the commands are specific for every particular package manager, they are to

6370-721: The process of adding and removing software from a running system. By around 1995, beginning with CPAN , package managers began doing the work of downloading packages from a repository, automatically resolving its dependencies and installing them as needed, making it much easier to install, uninstall and update software from a system. A software package is an archive file containing a computer program as well as necessary metadata for its deployment. The computer program can be in source code that has to be compiled and built first. Package metadata include package description, package version, and dependencies (other packages that need to be installed beforehand). Package managers are charged with

6461-444: The roll-back feature of Nix , if a system update leaves users with a broken system, users can easily roll back individual packages as well as the whole system state with a simple command: guix package --roll-back This means that the kind of stable channel that is very common in other Linux distributions is no longer needed for users who are willing to report a bug and wait a few minutes, when trying to update via guix pull . This

6552-402: The same path and filename, first of which is a symlink to some location outside current directory, and second of which is a regular file; then extracting such archive on some tar implementations may cause writing to the location pointed to by the symlink). Historically, many systems have implemented tar, and many general file archivers have at least partial support for tar (often using one of

6643-406: The second one if it is later instantiated without the need for any further reconfiguration or setup. Shepherd also provides virtual services which allow dynamic dispatch over a class of related service objects, such as all those which instantiate a mail transfer agent (MTA) for the system. A system governed via the Shepherd daemon can represent its user space as a directed acyclic graph , with

6734-448: The software system. They typically reside within a directory tree that is not maintained by the system-level package manager, such as c:\cygwin or /opt/sw . However, this might not be the case for the package managers that deal with programming libraries, leading to a possible conflict as both package managers may claim to "own" a file and might break upgrades. In 2016, Edgard Marx, a computer scientist from Leipzig University, coined

6825-564: The software's name, description of its purpose, version number, vendor, checksum (preferably a cryptographic hash function ), and a list of dependencies necessary for the software to run properly. Upon installation, metadata is stored in a local package database. Package managers typically maintain a database of software dependencies and version information to prevent software mismatches and missing prerequisites. They work closely with software repositories , binary repository managers , and app stores . Package managers are designed to eliminate

6916-409: The star extensions to support ACLs. More recent versions of GNU tar support Linux extended attributes, reimplementing star extensions. A number of extensions are reviewed in the filetype manual for BSD tar, tar(5). A tarbomb , in hacker slang , is a tar file that contains many files that extract into the working directory. Such a tar file can create problems by overwriting files of the same name in

7007-477: The state of the local system to fall out of synchronization with the state of the package manager's database . The local administrator will be required to take additional measures, such as manually managing some dependencies or integrating the changes into the package manager. There are tools available to ensure that locally compiled packages are integrated with the package management. For distributions based on .deb and .rpm files as well as Slackware Linux, there

7098-400: The store. Guix - like Nix - has built-in garbage collection facilities to help prune dead store items and keep the live ones. This is an example of a package definition for the hello-package: It is written using Guile. The package recipes can easily be inspected (running e.g. guix edit hello ) and changed in Guix, making the system transparent and very easy to modify. Inherited from

7189-630: The support of the GNU Hurd kernel under development. On February 3, 2015, the Free Software Foundation added the distribution to its list of endorsed free Linux distributions. The following CPU architectures are supported at the moment: System services, which are defined in the Guile Scheme, enable the user to declaratively compose the configuration of daemons and background services and specify configurations. This enables

7280-521: The system should function (see MicroOS ). The Guix package manager, like Nix , can however be used on many distributions like Debian and Parabola . This also enables multiple users to safely install software on the same system without administrator privileges. Compared to traditional package managers, Guix package stores can grow considerably bigger and therefore require more bandwidth; although compared to container solutions (like Docker ) that are also commonly employed to solve dependency hell , Guix

7371-410: The tape between blocks (for the tape to physically start and stop moving). Some tape drives (and raw disks) support only fixed-length data blocks. Also, when writing to any medium such as a file system or network, it takes less time to write one large block than many small blocks. Therefore, the tar command writes data in records of many 512  B blocks. The user can specify a blocking factor, which

7462-758: The tar command was indicated for withdrawal in favor of pax command at least since 1994. Today, Unix-like operating systems usually include tools to support tar files, as well as utilities commonly used to compress them, such as xz , gzip , and bzip2 . The tar command has also been ported to the IBM i operating system. BSD-tar has been included in Microsoft Windows since Windows 10 April 2018 Update , and there are otherwise multiple third party tools available to read and write these formats on Windows. Many historic tape drives read and write variable-length data blocks , leaving significant wasted space on

7553-466: The task of finding, installing, maintaining or uninstalling software packages upon the user's command. Typical functions of a package management system include: Computer systems that rely on dynamic library linking, instead of static library linking, share executable libraries of machine instructions across packages and applications. In these systems, conflicting relationships between different packages requiring different versions of libraries results in

7644-567: The term Data Dependency Management to refer to the systems that deal with the management of data. Data Dependency Management systems are designed to facilitate the deployment and management of data on the cloud, personal computers, or smart devices (edge). Data Dependency Management frameworks can be used to describe how the data was conceived, licensing as well as its dependencies. The concept of data dependency management comes from software package dependency management tools such as npm for JavaScript, gem for Ruby, and NuGet for .NET. Their rationale

7735-402: The time named GuixSD), and said, "GuixSD has a package manager that I like", but criticized the limited hardware support and its limited documentation. The documentation has since then been expanded and improved with videos and a cookbook in six languages with tutorials, how-to guides and examples. One particular area where Guix can offer to the user improvements over traditional package managers

7826-486: The user, within a single configuration file or modularized configuration, to configure the whole operating system (e.g., to have a Tor proxy , an ssh server, and a webserver serving guix-web via nginx on a specific port at bootup). They can: The Guix System uses the GNU Daemon Shepherd, formerly known as "dmd" ("Daemon managing Daemons"), as its init system, which is developed in tandem with Guix and

7917-473: The values with spaces instead of zeroes. The checksum is calculated by taking the sum of the unsigned byte values of the header record with the eight checksum bytes taken to be ASCII spaces (decimal value 32). It is stored as a six digit octal number with leading zeroes followed by a NUL and then a space. Various implementations do not adhere to this format. In addition, some historic tar implementations treated bytes as signed. Implementations typically calculate

8008-508: The working directory and, like a tarbomb, have the potential to overwrite existing files. However, modern versions of FreeBSD and GNU tar do not create or extract absolute paths and parent-directory references by default, unless it is explicitly allowed with the flag -P or the option --absolute-names . The bsdtar program, which is also available on many operating systems and is the default tar utility on Mac OS X v10.6, also does not follow parent-directory references or symbolic links. If

8099-491: The working directory, or mixing one project's files into another. It is at best an inconvenience to the user, who is obliged to identify and delete a number of files interspersed with the directory's other contents. Such behavior is considered bad etiquette on the part of the archive's creator. A related problem is the use of absolute paths or parent directory references when creating tar files. Files extracted from such archives will often be created in unusual locations outside

8190-451: Was created in the early days of Unix, and despite current widespread use, many of its design features are considered dated. Other formats have been created to address the shortcomings of tar. Due to the field size , the original TAR format was unable to store file paths and names in excess of 100 characters. To overcome this problem while maintaining readability by existing TAR utilities , GNU tar stores file paths and names in excess of

8281-570: 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 ustar file format;

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