Concept
File format
Related concepts (38)
File (command)
The file command is a standard program of Unix and Unix-like operating systems for recognizing the type of data contained in a . The original version of file originated in Unix Research Version 4 in 1973. System V brought a major update with several important changes, most notably moving the file type information into an external text file rather than compiling it into the binary itself. Most major BSD and Linux distributions use a free, open-source reimplementation which was written in 1986–87 by Ian Darwin from scratch.
Filename extension
A filename extension, file name extension or file extension is a suffix to the of a (for example, .txt, .docx, .md). The extension indicates a characteristic of the file contents or its intended use. A filename extension is typically delimited from the rest of the filename with a full stop (period), but in some systems it is separated with spaces. Other extension formats include dashes and/or underscores on early versions of Linux and some versions of IBM AIX.
XHTML
Extensible HyperText Markup Language (XHTML) is part of the family of XML markup languages. It mirrors or extends versions of the widely used HyperText Markup Language (HTML), the language in which Web pages are formulated. While HTML, prior to HTML5, was defined as an application of Standard Generalized Markup Language (SGML), a flexible markup language framework, XHTML is an application of XML, a more restrictive subset of SGML. XHTML documents are well-formed and may therefore be parsed using standard XML parsers, unlike HTML, which requires a lenient HTML-specific parser.
Text file
A text file (sometimes spelled textfile; an old alternative name is flatfile) is a kind of that is structured as a sequence of of electronic text. A text file exists stored as data within a . In operating systems such as CP/M and MS-DOS, where the operating system does not keep track of the file size in bytes, the end of a text file is denoted by placing one or more special characters, known as an (EOF) marker, as padding after the last line in a text file.
Comparison of data-serialization formats
This is a comparison of data serialization s, various ways to convert complex objects to sequences of bits. It does not include markup languages used exclusively as s.
Magic number (programming)
In computer programming, a magic number is any of the following: A unique value with unexplained meaning or multiple occurrences which could (preferably) be replaced with a named constant A constant numerical or text value used to identify a or protocol; for files, see A distinctive unique value that is unlikely to be mistaken for other meanings (e.g., Globally Unique Identifiers) The term magic number or magic constant refers to the anti-pattern of using numbers directly in source code.
Electronic document
An electronic document is any electronic media content (other than computer programs or system files) that is intended to be used in either an electronic form or as printed output. Originally, any computer data were considered as something internal — the final data output was always on paper. However, the development of computer networks has made it so that in most cases it is much more convenient to distribute electronic documents than printed ones.
Configuration file
In computing, configuration files (commonly known simply as config files) are s used to configure the parameters and initial settings for some computer programs. They are used for user applications, server processes and operating system settings. Some applications provide tools to create, modify, and verify the syntax of their configuration files; these sometimes have graphical interfaces. For other programs, system administrators may be expected to create and modify files by hand using a text editor, which is possible because many are human-editable plain text files.
System time
In computer science and computer programming, system time represents a computer system's notion of the passage of time. In this sense, time also includes the passing of days on the calendar. System time is measured by a system clock, which is typically implemented as a simple count of the number of ticks that have transpired since some arbitrary starting date, called the epoch. For example, Unix and POSIX-compliant systems encode system time ("Unix time") as the number of seconds elapsed since the start of the Unix epoch at 1 January 1970 00:00:00 UT, with exceptions for leap seconds.
XML schema
An XML schema is a description of a type of XML document, typically expressed in terms of constraints on the structure and content of documents of that type, above and beyond the basic syntactical constraints imposed by XML itself. These constraints are generally expressed using some combination of grammatical rules governing the order of elements, Boolean predicates that the content must satisfy, data types governing the content of elements and attributes, and more specialized rules such as uniqueness and referential integrity constraints.