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https://github.com/validator/validator
Nu Html Checker – Helps you catch problems in your HTML/CSS/SVG
https://github.com/validator/validator
devtools html-checker html-linter html-validation linter style-linter w3c web-development web-standards whatwg
Last synced: about 9 hours ago
JSON representation
Nu Html Checker – Helps you catch problems in your HTML/CSS/SVG
- Host: GitHub
- URL: https://github.com/validator/validator
- Owner: validator
- License: mit
- Created: 2010-12-03T02:00:23.000Z (about 14 years ago)
- Default Branch: main
- Last Pushed: 2024-10-17T01:38:30.000Z (3 months ago)
- Last Synced: 2024-10-29T11:15:15.296Z (3 months ago)
- Topics: devtools, html-checker, html-linter, html-validation, linter, style-linter, w3c, web-development, web-standards, whatwg
- Language: Java
- Homepage: https://validator.github.io/validator/
- Size: 23.8 MB
- Stars: 1,697
- Watchers: 64
- Forks: 273
- Open Issues: 284
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- Contributing: CONTRIBUTING.md
- License: LICENSE
- Security: SECURITY.md
Awesome Lists containing this project
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- jimsghstars - validator/validator - Nu Html Checker – Helps you catch problems in your HTML/CSS/SVG (Java)
README
# The Nu Html Checker (v.Nu) [![Chat room][1]][2] [![Download latest][3]][4]
[1]: resources/matrix-chat.svg
[2]: https://matrix.to/#/#validator_validator:gitter.im
[3]: resources/download-latest.svg
[4]: https://github.com/validator/validator/releases/latest
The Nu Html Checker (v.Nu) helps you [catch unintended mistakes in your HTML,
CSS, and SVG][5]. It enables you to [batch-check documents from the command
line][6] and from other scripts/apps, and to [deploy your own instance of the
checker as a service][7] (like [validator.w3.org/nu][8]). Its [source code is
available][9], as are [instructions on how to build, test, and run the
code][10].
[5]: https://validator.w3.org/nu/about.html#why-validate
[6]: https://validator.github.io/validator/#usage
[7]: https://validator.github.io/validator/#standalone
[8]: https://validator.w3.org/nu/
[9]: https://github.com/validator/validator
[10]: https://validator.github.io/validator/#build-instructions
A [Dockerfile][11] (see **Pulling the Docker image** below) and [npm][12],
[pip][13], and [brew][14] packages are also available.
[11]: https://ghcr.io/validator/validator
[12]: https://www.npmjs.com/package/vnu-jar
[13]: https://github.com/svenkreiss/html5validator
[14]: https://formulae.brew.sh/formula/vnu
It is released upstream in these formats:
* pre-compiled Linux, Windows, and macOS binaries that include an embedded
Java runtime
* `vnu.jar` — a portable version you can use on any system that has Java 11 or
above installed
* `vnu.war` — for [deploying the checker service through a servlet container
such as Tomcat][15]
[15]: https://validator.github.io/validator/#servlet
**Note:** The _vnu.jar_ and _vnu.war_ files require you to have Java 11 or above
installed. The pre-compiled Linux, Windows, and macOS binaries don’t require you
to have any version of Java already installed at all.
You can [get the latest release][16] or run [`docker run -it --rm -p 8888:8888
ghcr.io/validator/validator:latest`][17], [`npm install vnu-jar`][18],
[`npm install --registry=https://npm.pkg.github.com @validator/vnu-jar`][19],
[`brew install vnu`][20], or [`pip install html5validator`][21] and see the
**Usage** and **Web-based checking** sections below. Or automate your document
checking with a frontend such as:
[16]: https://github.com/validator/validator/releases/latest
[17]: https://github.com/validator/validator/pkgs/container/validator
[18]: https://www.npmjs.com/package/vnu-jar
[19]: https://github.com/validator/validator/packages/892707
[20]: https://libraries.io/homebrew/vnu
[21]: https://github.com/svenkreiss/html5validator
* [Grunt plugin for HTML validation][22] or [Gulp plugin for HTML
validation][23] or [Maven plugin for HTML validation][24]
* [html5validator `pip` package][25] (for integration in Travis CI, CircleCI,
CodeShip, Jekyll, Pelican, etc.)
* [LMVTFY: Let Me Validate That For You][26] (auto-check JSFiddle/JSBin, etc.,
links in GitHub issue comments)
[22]: https://github.com/validator/grunt-html
[23]: https://github.com/validator/gulp-html
[24]: https://github.com/validator/maven-plugin
[25]: https://github.com/svenkreiss/html5validator
[26]: https://github.com/cvrebert/lmvtfy/
## Usage
Run the checker with one of the following invocations:
• `vnu-runtime-image/bin/vnu OPTIONS FILES` (Linux or macOS)
• `vnu-runtime-image\bin\vnu.bat OPTIONS FILES` (Windows)
• `java -jar ~/vnu.jar OPTIONS FILES` (any system with Java8+ installed)
…where _`FILES`_ are the documents to check, and _`OPTIONS`_ are zero or more of
the following options:
--errors-only --Werror --exit-zero-always --stdout --asciiquotes
--user-agent USER_AGENT --no-langdetect --no-stream --filterfile FILENAME
--filterpattern PATTERN --css --skip-non-css --also-check-css --svg
--skip-non-svg --also-check-svg --xml --html --skip-non-html
--format gnu|xml|json|text --help --verbose --version
The [Options][27] section below provides details on each option, and the rest of
this section provides some specific examples.
[27]: https://validator.github.io/validator/#options
**Note:** Throughout these examples, replace `~/vnu.jar` with the actual path to
that jar file on your system, and replace `vnu-runtime-image/bin/vnu` and
`vnu-runtime-image\bin\vnu.bat` with the actual path to the `vnu` or `vnu.bat`
program on your system — or if you add the `vnu-runtime-image/bin` or
`vnu-runtime-image\bin` directory your system `PATH` environment variable, you
can invoke the checker with just `vnu`.
To check one or more documents from the command line:
vnu-runtime-image/bin/vnu FILE.html FILE2.html FILE3.html...
vnu-runtime-image\bin\vnu.bat FILE.html FILE2.html FILE3.html...
java -jar ~/vnu.jar FILE.html FILE2.html FILE3.html...
**Note:** If you get a `StackOverflowError` error when invoking the checker, try
adjusting the thread stack size by providing the `-Xss` option to java:
java -Xss512k -jar ~/vnu.jar ...
vnu-runtime-image/bin/java -Xss512k \
-m vnu/nu.validator.client.SimpleCommandLineValidator ...
To check all documents in a particular directory `DIRECTORY_PATH` as HTML:
java -jar ~/vnu.jar DIRECTORY_PATH
vnu-runtime-image/bin/vnu DIRECTORY_PATH
vnu-runtime-image\bin\vnu.bat DIRECTORY_PATH
#### More examples
**Note:** The examples in this section assume you have the
`vnu-runtime-image/bin` or `vnu-runtime-image\bin` directory in your system
`PATH` environment variable. If you’re using the jar file instead, replace `vnu`
in the examples with `java -jar ~/vnu.jar`.
To check all documents in a particular directory `DIRECTORY_PATH` as HTML, but
skip any documents whose names don’t end with the extensions `.html`, `.htm`,
`.xhtml`, or `.xht`:
vnu --skip-non-html DIRECTORY_PATH
To check all documents in a particular directory as CSS:
vnu --css DIRECTORY_PATH
To check all documents in a particular directory as CSS, but skip any documents
whose names don’t end with the extension `.css`:
vnu --skip-non-css DIRECTORY_PATH
To check all documents in a particular directory, with documents whose names end
in the extension `.css` being checked as CSS, and all other documents being
checked as HTML:
vnu --also-check-css DIRECTORY_PATH
To check all documents in a particular directory as SVG:
vnu --svg DIRECTORY_PATH
To check all documents in a particular directory as SVG, but skip any documents
whose names don’t end with the extension `.svg`:
vnu --skip-non-svg DIRECTORY_PATH
To check all documents in a particular directory, with documents whose names end
in the extension `.svg` being checked as SVG, and all other documents being
checked as HTML:
vnu --also-check-svg DIRECTORY_PATH
To check a Web document:
vnu _URL_
example: vnu http://example.com/foo
To check standard input:
vnu -
example:
echo '...' | vnu -
echo '...' | java -jar ~/vnu.jar -
### Options
When used from the command line as described in this section, the checker
provides the following options:
#### --asciiquotes
Specifies whether ASCII quotation marks are substituted for Unicode smart
quotation marks in messages.
default: [unset; Unicode smart quotation marks are used in messages]
#### --errors-only
Specifies that only error-level messages and non-document-error messages are
reported (so that warnings and info messages are not reported).
default: [unset; all messages reported, including warnings & info messages]
#### --Werror
Makes the checker exit non-zero if any warnings are encountered (even if
there are no errors).
default: [unset; checker exits zero if only warnings are encountered]
#### --exit-zero-always
Makes the checker exit zero even if errors are reported for any documents.
default: [unset; checker exits 1 if errors are reported for any documents]
#### --stdout
Makes the checker report errors and warnings to stdout rather than stderr.
default: [unset; checker reports errors and warnings to stderr]
#### --filterfile _FILENAME_
Specifies a filename. Each line of the file contains either a regular
expression or starts with "#" to indicate the line is a comment. Any error
message or warning message that matches a regular expression in the file is
filtered out (dropped/suppressed).
default: [unset; checker does no message filtering]
#### --filterpattern _REGEXP_
Specifies a regular expression. Any error message or warning message that
matches the regular expression is filtered out (dropped/suppressed).
As with all other checker options, this option may only be specified once.
So to filter multiple error messages or warning messages, you must provide a
single regular expression that will match all the messages. The typical way
to do that for regular expressions is to OR multiple patterns together using
the "|" character.
default: [unset; checker does no message filtering]
#### --format _format_
Specifies the output format for reporting the results.
default: "gnu"
possible values: "gnu", "xml", "json", "text" [see information at URL below]
https://github.com/validator/validator/wiki/Service-%C2%BB-Common-params#out
#### --help
Shows detailed usage information.
#### --skip-non-css
Check documents as CSS but skip documents that don’t have *.css extensions.
default: [unset; all documents found are checked]
#### --css
Force all documents to be checked as CSS, regardless of extension.
default: [unset]
#### --skip-non-svg
Check documents as SVG but skip documents that don’t have *.svg extensions.
default: [unset; all documents found are checked]
#### --svg
Force all documents to be checked as SVG, regardless of extension.
default: [unset]
#### --skip-non-html
Skip documents that don’t have *.html, *.htm, *.xhtml, or *.xht extensions.
default: [unset; all documents found are checked, regardless of extension]
#### --html
Forces any *.xhtml or *.xht documents to be parsed using the HTML parser.
default: [unset; XML parser is used for *.xhtml and *.xht documents]
#### --xml
Forces any *.html documents to be parsed using the XML parser.
default: [unset; HTML parser is used for *.html documents]
#### --also-check-css
Check CSS documents (in addition to checking HTML documents).
default: [unset; no documents are checked as CSS]
#### --also-check-svg
Check SVG documents (in addition to checking HTML documents).
default: [unset; no documents are checked as SVG]
#### --user-agent _USER_AGENT_
Specifies the value of the User-Agent request header to send when checking
HTTPS/HTTP URLs.
default: "Validator.nu/LV"
#### --no-langdetect
Disables language detection, so that documents are not checked for missing
or mislabeled html[lang] attributes.
default: [unset; language detection & html[lang] checking are performed]
#### --no-stream
Forces all documents to be be parsed in buffered mode instead of streaming
mode (causes some parse errors to be treated as non-fatal document errors
instead of as fatal document errors).
default: [unset; non-streamable parse errors cause fatal document errors]
#### --verbose
Specifies "verbose" output. (Currently this just means that the names of
files being checked are written to stdout.)
default: [unset; output is not verbose]
#### --version
Shows the checker version number.
## Web-based checking
The Nu Html Checker — along with being usable as [a standalone command-line
client][28] — can be run as an HTTP service, similar to
[validator.w3.org/nu][29], for browser-based checking of HTML documents, CSS
stylesheets, and SVG images over the Web. To that end, the checker is released
as several separate packages:
[28]: https://validator.github.io/validator/#usage
[29]: https://validator.w3.org/nu/
* Linux, Windows, and macOS binaries for deploying the checker as a simple
self-contained service on any system
* `vnu.jar` for deploying the checker as a simple self-contained service on a
system with Java installed
* `vnu.war` for deploying the checker to a servlet container such as Tomcat
All deployments expose a REST API that enables checking of HTML documents, CSS
stylesheets, and SVG images from other clients, not just web browsers. And the
Linux, Windows, and macOS binaries and `vnu.jar` package also include a simple
HTTP client that enables you to either send documents to a locally-running
instance of the checker HTTP service — for fast command-line checking — or to
any remote instance of the checker HTTP service running anywhere on the Web.
The [latest releases of the Linux, Windows, and macOS binaries and vnu.jar and
vnu.war packages][30] are available from the `validator` project at github. The
following are detailed instructions on using them.
[30]: https://github.com/validator/validator/releases/latest
**Note:** Throughout these instructions, replace `~/vnu.jar` with the actual
path to that jar file on your system, and replace `vnu-runtime-image/bin/java`
and `vnu-runtime-image\bin\java.exe` with the actual path to the checker `java`
or `java.exe` program on your system — or if you add the `vnu-runtime-image/bin`
or `vnu-runtime-image\bin` directory your system `PATH` environment variable,
you can invoke the checker with just `java nu.validator.servlet.Main 8888`.
### Standalone web server
To run the checker as a standalone service (using a built-in Jetty server), open
a new terminal window and invoke the checker like this:
java -cp ~/vnu.jar nu.validator.servlet.Main 8888
vnu-runtime-image/bin/java nu.validator.servlet.Main 8888
vnu-runtime-image\bin\java.exe nu.validator.servlet.Main 8888
Then open [http://0.0.0.0:8888][31] in a browser. (To listen on a different
port, replace `8888` with the port number.)
[31]: http://0.0.0.0:8888
**Warning:** Future checker releases will bind by default to the address
`127.0.0.1`. Your checker deployment might become unreachable unless you use the
`nu.validator.servlet.bind-address` system property to bind the checker to a
different address:
java -cp ~/vnu.jar \
-Dnu.validator.servlet.bind-address=128.30.52.73 \
nu.validator.servlet.Main 8888
vnu-runtime-image/bin/java \
-Dnu.validator.servlet.bind-address=128.30.52.73 \
nu.validator.servlet.Main 8888
vnu-runtime-image\bin\java.exe \
-Dnu.validator.servlet.bind-address=128.30.52.73 \
nu.validator.servlet.Main 8888
When you open [http://0.0.0.0:8888][32] (or whatever URL corresponds to the
`nu.validator.servlet.bind-address` value you’re using), you’ll see a form
similar to [validator.w3.org/nu][33] that allows you to enter the URL of an HTML
document, CSS stylesheet, or SVG image, and have the results of checking that
resource displayed in the browser.
[32]: http://0.0.0.0:8888
[33]: https://validator.w3.org/nu/
**Note:** If you get a `StackOverflowError` error when using the checker, try
adjusting the thread stack size by providing the `-Xss` option to java:
java -Xss512k -cp ~/vnu.jar nu.validator.servlet.Main 8888
vnu-runtime-image/bin/java -Xss512k -m vnu/nu.validator.servlet.Main 8888
### Deployment to servlet container
To run the checker inside of an existing servlet container such as Apache Tomcat
you will need to deploy the `vnu.war` file to that server following its
documentation. For example, on Apache Tomcat you could do this using the
[Manager][34] application or simply by copying the file to the `webapps`
directory (since that is the default `appBase` setting). Typically you would see
a message similar to the following in the `catalina.out` log file.
[34]: https://tomcat.apache.org/tomcat-8.0-doc/manager-howto.html
May 7, 2014 4:42:04 PM org.apache.catalina.startup.HostConfig deployWAR
INFO: Deploying web application archive /var/lib/tomcat7/webapps/vnu.war
Assuming your servlet container is configured to receive HTTP requests sent to
`localhost` on port `80` and the context root of this application is `vnu`
(often the default behavior is to use the WAR file's filename as the context
root unless one is explicitly specified) you should be able to access the
application by connecting to [http://localhost/vnu/][35].
[35]: http://localhost/vnu/
**Note:** You may want to customize the `/WEB-INF/web.xml` file inside the WAR
file (you can use any ZIP-handling program) to modify the servlet filter
configuration. For example, if you wanted to disable the inbound-size-limit
filter, you could comment out that filter like this:
### HTTP client (for fast command-line checking)
The checker is packaged with an HTTP client you can use from the command line to
either send documents to a locally-running instance of the checker HTTP service
— for fast command-line checking — or to a remote instance anywhere on the Web.
To check documents locally using the packaged HTTP client, do this:
1. Start up the checker as a local HTTP service, as described in the
**Standalone web server** section.
2. Open a new terminal window and invoke the HTTP client like this:
java -cp ~/vnu.jar nu.validator.client.HttpClient FILE.html...
vnu-runtime-image/bin/java nu.validator.client.HttpClient FILE.html...
To send documents to an instance of the checker on the Web, such as
[html5.validator.nu/][36], use the nu.validator.client.host and
nu.validator.client.port options, like this:
[36]: https://html5.validator.nu/
java -cp ~/vnu.jar -Dnu.validator.client.port=80 \
-Dnu.validator.client.host=html5.validator.nu \
nu.validator.client.HttpClient FILE.html...
…or like this:
vnu-runtime-image/bin/java -Dnu.validator.client.port=80 \
-Dnu.validator.client.host=html5.validator.nu \
nu.validator.client.HttpClient FILE.html...
Other options are documented below.
### HTTP client options
When using the packaged HTTP client for sending documents to an instance of the
checker HTTP service for checking, you can set Java system properties to control
configuration options for the checker behavior.
For example, you can suppress warning-level messages and only show error-level
ones by setting the value of the `nu.validator.client.level` system property to
`error`, like this:
java -Dnu.validator.client.level=error \
-cp ~/vnu.jar nu.validator.client.HttpClient FILE.html...
…or like this:
vnu-runtime-image/bin/java -Dnu.validator.client.level=error \
-cp ~/vnu.jar nu.validator.client.HttpClient FILE.html...
Most of the properties listed below map to the common input parameters for the
checker service, as documented at
[github.com/validator/validator/wiki/Service-»-Common-params][37].
[37]: https://github.com/validator/validator/wiki/Service-%C2%BB-Common-params
#### nu.validator.client.host
Specifies the hostname of the checker for the client to connect to.
default: "127.0.0.1"
#### nu.validator.client.port
Specifies the hostname of the checker for the client to connect to.
default: "8888"
example: java -Dnu.validator.client.port=8080 -jar ~/vnu.jar FILE.html
#### nu.validator.client.level
Specifies the severity level of messages to report; to suppress
warning-level messages, and only show error-level ones, set this property to
"error".
default: [unset]
possible values: "error"
example: java -Dnu.validator.client.level=error -jar ~/vnu.jar FILE.html
#### nu.validator.client.parser
Specifies which parser to use.
default: "html"; or, for *.xhtml input files, "xml"
possible values: [see information at URL below]
https://github.com/validator/validator/wiki/Service-%C2%BB-Common-params#parser
#### nu.validator.client.charset
Specifies the encoding of the input document.
default: [unset]
#### nu.validator.client.content-type
Specifies the content-type of the input document.
default: "text/html"; or, for *.xhtml files, "application/xhtml+xml"
#### nu.validator.client.out
Specifies the output format for messages.
default: "gnu"
possible values: [see information at URL below]
https://github.com/validator/validator/wiki/Service-%C2%BB-Common-params#out
#### nu.validator.client.asciiquotes
Specifies whether ASCII quotation marks are substituted for Unicode smart
quotation marks in messages.
default: "yes"
possible values: "yes" or "no"
### HTTP servlet options
#### nu.validator.servlet.bind-address
Binds the validator service to the specified IP address.
default: 0.0.0.0 [causes the checker to listen on all interfaces]
possible values: The IP address of any network interface
example: -Dnu.validator.servlet.bind-address=127.0.0.1
#### nu.validator.servlet.connection-timeout
Specifies the connection timeout.
default: 5000
possible values: number of milliseconds
example: -Dnu.validator.servlet.connection-timeout=5000
#### nu.validator.servlet.socket-timeout
Specifies the socket timeout.
default: 5000
possible values: number of milliseconds
example: -Dnu.validator.servlet.socket-timeout=5000
## Pulling the Docker image
You can pull the checker Docker image from
[https://ghcr.io/validator/validator][38] in the GitHub container registry.
[38]: https://ghcr.io/validator/validator
To pull and run the latest version of the checker:
docker run -it --rm -p 8888:8888 ghcr.io/validator/validator:latest
To pull and run a specific tag/version of the checker from the container
registry — for example, the `17.11.1` version:
docker run -it --rm -p 8888:8888 ghcr.io/validator/validator:17.11.1
To bind the checker to a specific address (rather than have it listening on all
interfaces):
docker run -it --rm -p 128.30.52.73:8888:8888
ghcr.io/validator/validator:latest
To make the checker run with a connection timeout and socket timeout different
than the default 5 seconds, use the `CONNECTION_TIMEOUT_SECONDS` and
`SOCKET_TIMEOUT_SECONDS` environment variables:
docker run -it --rm \
-e CONNECTION_TIMEOUT_SECONDS=15 \
-e SOCKET_TIMEOUT_SECONDS=15 \
-p 8888:8888 \
validator/validator
To make the checker run with particular Java system properties set, use the
`JAVA_TOOL_OPTIONS` environment variable:
docker run -it --rm \
-e JAVA_TOOL_OPTIONS=-Dnu.validator.client.asciiquotes=yes \
-p 8888:8888 \
validator/validator
To define a service named `vnu` for use with `docker compose`, create a Compose
file named `docker-compose.yml` (for example), with contents such as the
following:
version: '2' services:
vnu:
image: validator/validator ports:
- "8888:8888"
network_mode: "host" #so "localhost" refers to the host machine.
## Build instructions
Follow the steps below to build, test, and run the checker such that you can
open `http://0.0.0.0:8888/` in a Web browser to use the checker Web UI.
1. Make sure you have git, python, and JDK 8 or above installed.
2. Set the `JAVA_HOME` environment variable:
export JAVA_HOME=/usr/lib/jvm/java-8-openjdk-amd64 <-- Ubuntu, etc.
export JAVA_HOME=$(/usr/libexec/java_home) <-- MacOS
3. Create a working directory:
git clone https://github.com/validator/validator.git
4. Change into your working directory:
cd validator
5. Start the checker Python script:
python ./checker.py all
The first time you run the checker Python script, you’ll need to be online and
the build will need time to download several megabytes of dependencies.
The steps above will build, test, and run the checker such that you can open
`http://0.0.0.0:8888/` in a Web browser to use the checker Web UI.
**Warning:** Future checker releases will bind by default to the address
`127.0.0.1`. Your checker deployment might become unreachable unless you use the
`--bind-address` option to bind the checker to a different address:
python ./checker.py --bind-address=128.30.52.73 all
Use `python ./checker.py --help` to see command-line options for controlling the
behavior of the script, as well as build-target names you can call separately;
e.g.:
* python ./checker.py build # to build only
* python ./checker.py build test # to build and test
* python ./checker.py run # to run only
* python ./checker.py jar # to compile vnu.jar
* python ./checker.py update-shallow && \
python ./checker.py dldeps && \
python ./checker.py jar # to compile vnu.jar faster