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Mbox
Mbox is a generic term for a family of related file formats used for holding collections of email messages. It was first implemented in Research Unix, Fifth Edition Unix. All messages in an mbox mailbox are Concatenation, concatenated and stored as plain text in a single file. Each message starts with the four characters "From" followed by a space (the so-called "From_ line") and the sender's email address. RFC 4155 defines that a UTC timestamp follows after another separating space character. A format similar to mbox is the MH Message Handling System. Other systems, such as Microsoft Exchange Server and the Cyrus (imapd), Cyrus IMAP server, store mailboxes in centralized databases managed by the mail system and not directly accessible by individual users. The maildir mailbox format is often cited as an alternative to the mbox format for networked email storage systems. Mail storage protocols Unlike the Internet protocols used for the exchange of email, the format used for th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
File Format
A file format is a Computer standard, standard way that information is encoded for storage in a computer file. It specifies how bits are used to encode information in a digital storage medium. File formats may be either proprietary format, proprietary or open format, open. Some file formats are designed for very particular types of data: Portable Network Graphics, PNG files, for example, store Raster graphics, bitmapped Graphics file format, images using lossless data compression. Other file formats, however, are designed for storage of several different types of data: the Ogg format can act as a container format (digital), container for different types of multimedia including any combination of sound, audio and video, with or without text (such as subtitles), and metadata. A text file can contain any stream of characters, including possible control characters, and is encoded in one of various Character encoding, character encoding schemes. Some file formats, such as HTML, sca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mailx
mailx is a Unix utility program for sending and receiving mail, also known as a Mail User Agent program. Being a console application with a command syntax similar to ed, it is the POSIX standardized variant of the Berkeley Mail utility. See also * mail (Unix) References External links * History of mail and mailxfrom the Heirloom Project mailx Tutorialfrom the engineering Dpt. at Purdue University Purdue University is a Public university#United States, public Land-grant university, land-grant research university in West Lafayette, Indiana, United States, and the flagship campus of the Purdue University system. The university was founded ... at GNU Mailutils manual Unix SUS2008 utilities Email client software for Linux Unix Internet software Free email software Console applications Software using the BSD license {{unix-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maildir
The Maildir e-mail format is a common way of storing email messages on a file system, rather than in a database. Each message is assigned a Computer file, file with a unique name, and each mail folder is a file system directory containing these files. Maildir was designed by Daniel J. Bernstein circa 1995, with a major goal of eliminating the need for program code to handle file locking and unlocking through use of the local filesystem. Maildir design reflects the fact that the only operations valid for an email message is that it be created, deleted or have its status changed in some way. __TOC__ Specifications A Maildir directory (file systems), directory (often named Maildir) usually has three subdirectories named tmp, new, and cur. * The tmp subdirectory temporarily stores e-mail messages that are in the process of being delivered. This subdirectory may also store other kinds of temporary files. * The new subdirectory stores messages that have been delivered, but have no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Version Control System
Version control (also known as revision control, source control, and source code management) is the software engineering practice of controlling, organizing, and tracking different versions in history of computer files; primarily source code text files, but generally any type of file. Version control is a component of software configuration management. A ''version control system'' is a software tool that automates version control. Alternatively, version control is embedded as a feature of some systems such as word processors, spreadsheets, collaborative web docs, and content management systems, e.g., Wikipedia's page history. Version control includes viewing old versions and enables reverting a file to a previous version. Overview As teams develop software, it is common to deploy multiple versions of the same software, and for different developers to work on one or more different versions simultaneously. Bugs or features of the software are often only present in ce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mailing List
A mailing list is a collection of names and addresses used by an individual or an organization to send material to multiple recipients. Mailing lists are often rented or sold. If rented, the renter agrees to use the mailing list only at contractually agreed-upon times. The mailing list owner typically enforces this by " salting" (known as "seeding" in direct mail) the mailing list with fake addresses and creating new salts for each time the list is rented. Unscrupulous renters may attempt to bypass salts by renting several lists and merging them to find common, valid addresses. Mailing list brokers exist to help organizations rent their lists. For some list owners, such as specialized niche publications or charitable groups, their lists may be some of their most valuable assets, and mailing list brokers help them maximize the value of their lists. Transmission may be paper-based or electronic. Each has its strengths, although a 2022 article claimed that compared to email, " di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diff
In computing, the utility diff is a data comparison tool that computes and displays the differences between the contents of files. Unlike edit distance notions used for other purposes, diff is line-oriented rather than character-oriented, but it is like Levenshtein distance in that it tries to determine the smallest set of deletions and insertions to create one file from the other. The utility displays the changes in one of several standard formats, such that both humans or computers can parse the changes, and use them for patching. Typically, ''diff'' is used to show the changes between two versions of the same file. Modern implementations also support binary files. The output is called a "diff", or a patch, since the output can be applied with the Unix program . The output of similar file comparison utilities is also called a "diff"; like the use of the word " grep" for describing the act of searching, the word ''diff'' became a generic term for calculating data difference ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Patch (Unix)
The computer tool patch is a Unix program that updates text files according to instructions contained in a separate file, called a ''patch file''. The patch file (also called a ''patch'' for short) is a text file that consists of a list of differences and is produced by running the related diff program with the original and updated file as arguments. Updating files with patch is often referred to as ''applying the patch'' or simply ''patching'' the files. History The original patch program was written by Larry Wall (who went on to create the Perl programming language) and posted to mod.sources (which later became comp.sources.unix) in May 1985. patch was added to XPG4, which later became POSIX. Wall's code remains the basis of "patch" programs provided in OpenBSD, FreeBSD, and schilytools. The Open Software Foundation, which merged into The Open Group, is said to have maintained a derived version. The GNU project/ FSF maintains its patch, forked from the Larry Wall version. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Open Source
Open source is source code that is made freely available for possible modification and redistribution. Products include permission to use and view the source code, design documents, or content of the product. The open source model is a decentralized software development model that encourages open collaboration. A main principle of Open-source software, open source software development is peer production, with products such as source code, blueprints, and documentation freely available to the public. The open source movement in software began as a response to the limitations of proprietary code. The model is used for projects such as in open source appropriate technology, and open source drug discovery. Open source promotes universal access via an open-source or free license to a product's design or blueprint, and universal redistribution of that design or blueprint. Before the phrase ''open source'' became widely adopted, developers and producers used a variety of other terms, suc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Network File System (protocol)
Network File System (NFS) is a distributed file system protocol originally developed by Sun Microsystems (Sun) in 1984, allowing a user on a client computer to access files over a computer network much like local storage is accessed. NFS, like many other protocols, builds on the Open Network Computing Remote Procedure Call (ONC RPC) system. NFS is an open IETF standard defined in a Request for Comments (RFC), allowing anyone to implement the protocol. Versions and variations Sun used version 1 only for in-house experimental purposes. When the development team added substantial changes to NFS version 1 and released it outside of Sun, they decided to release the new version as v2, so that version interoperation and RPC version fallback could be tested. NFSv2 Version 2 of the protocol (defined in , March 1989) originally operated only over User Datagram Protocol (UDP). Its designers meant to keep the server side Stateless server, stateless, with lock (computer s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
File Locking
File locking is a mechanism that restricts access to a computer file, or to a region of a file, by allowing only one user or process to modify or delete it at a specific time, and preventing reading of the file while it's being modified or deleted. Systems implement locking to prevent an ''interceding update'' scenario, which is an example of a race condition, by enforcing the serialization of update processes to any given file. The following example illustrates the interceding update problem: # Process A reads a customer record from a file containing account information, including the customer's account balance and phone number. # Process B now reads the same record from the same file, so it has its own copy. # Process A changes the account balance in its copy of the customer record and writes the record back to the file. # Process B, which still has the original ''stale'' value for the account balance in its copy of the customer record, updates the account balance and writes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
POSIX
The Portable Operating System Interface (POSIX; ) is a family of standards specified by the IEEE Computer Society for maintaining compatibility between operating systems. POSIX defines application programming interfaces (APIs), along with command line shells and utility interfaces, for software compatibility (portability) with variants of Unix and other operating systems. POSIX is also a trademark of the IEEE. POSIX is intended to be used by both application and system developers. As of POSIX 2024, the standard is aligned with the C17 language standard. Name Originally, the name "POSIX" referred to IEEE Std 1003.1-1988, released in 1988. The family of POSIX standards is formally designated as IEEE 1003 and the ISO/IEC standard number is ISO/ IEC 9945. The standards emerged from a project that began in 1984 building on work from related activity in the ''/usr/group'' association. Richard Stallman suggested the name ''POSIX'' to the IEEE instead of the former ''IEEE-IX''. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Email
Electronic mail (usually shortened to email; alternatively hyphenated e-mail) is a method of transmitting and receiving Digital media, digital messages using electronics, electronic devices over a computer network. It was conceived in the late–20th century as the digital version of, or counterpart to, mail (hence ''wikt:e-#Etymology 2, e- + mail''). Email is a ubiquitous and very widely used communication medium; in current use, an email address is often treated as a basic and necessary part of many processes in business, commerce, government, education, entertainment, and other spheres of daily life in most countries. Email operates across computer networks, primarily the Internet access, Internet, and also local area networks. Today's email systems are based on a store-and-forward model. Email Server (computing), servers accept, forward, deliver, and store messages. Neither the users nor their computers are required to be online simultaneously; they need to connect, ty ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
