vocabulary:
  name: Wget Vocabulary
  description: >-
    Domain vocabulary for GNU Wget and Wget2, covering file download operations,
    protocol support, recursive retrieval, plugin API concepts, and configuration
    options for the GNU command-line file downloading utility.
  version: '1.0'
  created: '2026-05-03'
  modified: '2026-05-03'
  tags:
    - CLI
    - File Download
    - HTTP Client
    - GNU
    - Open Source

  terms:

    - term: Wget
      definition: >-
        GNU Wget is a free, non-interactive command-line utility for downloading
        files from the web using HTTP, HTTPS, FTP, and FTPS protocols.
      tags:
        - Core

    - term: Wget2
      definition: >-
        The next-generation successor to GNU Wget, rewritten from scratch around
        the libwget library with support for HTTP/2, multi-threading, and a plugin API.
      tags:
        - Core

    - term: Libwget
      definition: >-
        A reusable C library providing core web client functionality used by Wget2,
        licensed under LGPLv3+. Provides modules for HTTP, TLS, cookies, DNS,
        encoding, IRI, and plugin support.
      tags:
        - Library

    - term: Recursive Download
      definition: >-
        The ability to follow links in HTML pages and download referenced files,
        recursively mirroring a website or directory structure locally.
      tags:
        - Feature

    - term: Resume
      definition: >-
        The ability to continue an interrupted or aborted download using HTTP REST
        and RANGE headers, avoiding re-downloading already-retrieved content.
      tags:
        - Feature

    - term: Mirror
      definition: >-
        Creating a local copy of a remote website or FTP directory by recursively
        downloading all files, using If-Modified-Since to only fetch updated files.
      tags:
        - Feature

    - term: wgetrc
      definition: >-
        The startup configuration file for GNU Wget, typically located at ~/.wgetrc
        or /etc/wgetrc, allowing default settings to be specified for command-line options.
      tags:
        - Configuration

    - term: Plugin API
      definition: >-
        The Wget2 extension mechanism allowing third-party plugins to intercept URLs
        before fetching, modify download behavior, and post-process downloaded files.
      tags:
        - Plugin API

    - term: Plugin Initializer
      definition: >-
        The required entry point function wget_plugin_initializer() that every Wget2
        plugin must implement; called when the plugin is loaded.
      tags:
        - Plugin API

    - term: URL Filter
      definition: >-
        A plugin callback registered via wget_plugin_register_url_filter_callback()
        that can accept, reject, or substitute URLs before Wget2 fetches them.
      tags:
        - Plugin API

    - term: Post Processor
      definition: >-
        A plugin callback registered via wget_plugin_register_post_processor() that
        processes files after they have been downloaded, with access to file contents
        and metadata.
      tags:
        - Plugin API

    - term: Metalink
      definition: >-
        An XML-based download description format supported by Wget2 that specifies
        multiple download mirrors and hash verification for files.
      tags:
        - Feature

    - term: Sitemap
      definition: >-
        An XML file that lists URLs for a website; Wget2 can scan Sitemap XML files
        to discover URLs for recursive downloading.
      tags:
        - Feature

    - term: RSS Feed
      definition: >-
        An XML syndication format; Wget2 can scan RSS 2.0 feeds to discover and
        download linked resources.
      tags:
        - Feature

    - term: Atom Feed
      definition: >-
        An XML syndication format; Wget2 can scan Atom 1.0 feeds to discover and
        download linked resources.
      tags:
        - Feature

    - term: HTTP Proxy
      definition: >-
        An intermediary server through which Wget routes HTTP requests, configurable
        via the http_proxy environment variable or wgetrc.
      tags:
        - Networking

    - term: Cookie
      definition: >-
        HTTP state management mechanism; Wget can load and save cookies to files
        using Netscape cookie format to support authenticated sessions.
      tags:
        - Networking

    - term: If-Modified-Since
      definition: >-
        An HTTP header used by Wget2 during mirroring to conditionally fetch files
        only if they have changed since the local copy was last downloaded.
      tags:
        - Networking

    - term: Persistent Connection
      definition: >-
        HTTP keep-alive connections that Wget maintains across multiple requests to
        the same server, reducing connection overhead.
      tags:
        - Networking

    - term: HTTP/2
      definition: >-
        The second major version of the HTTP protocol, supported by Wget2 for faster
        downloads through multiplexed streams and header compression.
      tags:
        - Networking

    - term: Intercept Action
      definition: >-
        The result object returned by a URL filter plugin callback that specifies
        whether to accept, reject, substitute, or rename the download.
      tags:
        - Plugin API

    - term: Recurse URL
      definition: >-
        A URL added to the download queue by a post-processor plugin via
        wget_downloaded_file_add_recurse_url() for further recursive retrieval.
      tags:
        - Plugin API

    - term: GNU Project
      definition: >-
        The free software initiative that produces GNU Wget as part of the GNU
        operating system, maintained by the Free Software Foundation.
      tags:
        - Governance

    - term: GPLv3
      definition: >-
        GNU General Public License version 3; the license under which GNU Wget and
        Wget2 are distributed.
      tags:
        - License

    - term: LGPLv3
      definition: >-
        GNU Lesser General Public License version 3; the license under which libwget
        is distributed, allowing use in proprietary applications.
      tags:
        - License