HTML5 Validator

https://github.com/svenkreiss/html5validator
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HTML5 Validator is a command line tool that tests files for HTML5 validity, with support for CSS and...
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### CodeShip Configuration for Ruby Projects

Source: https://github.com/svenkreiss/html5validator/blob/main/README.rst

Example setup for a Ruby project in CodeShip, including Ruby version management, dependency installation, environment setup, and HTML5 validation.

```yaml
rvm use 2.2.0 --install
bundle install
bundle update
export RAILS_ENV=test
jdk_switcher use oraclejdk8
pip install html5validator
```

--------------------------------

### CodeShip Setup Commands

Source: https://github.com/svenkreiss/html5validator/blob/main/README.rst

Add these lines to the 'Setup Commands' section in CodeShip to install Java 8 and the html5validator.

```yaml
jdk_switcher use oraclejdk8
pip install html5validator
```

--------------------------------

### Connection Timeout Example

Source: https://github.com/svenkreiss/html5validator/blob/main/vnujar/README.md

Example of setting the nu.validator.servlet.connection-timeout Java system property to specify the connection timeout in milliseconds.

```bash
-Dnu.validator.servlet.connection-timeout=5000
```

--------------------------------

### Configure Port Property

Source: https://github.com/svenkreiss/html5validator/blob/main/vnujar/README.md

Example of setting the port property via command line.

```bash
java -Dnu.validator.client.port=8080 -jar ~/vnu.jar FILE.html
```

--------------------------------

### Install and Run HTML5 Validator

Source: https://github.com/svenkreiss/html5validator/blob/main/README.rst

Install the validator using pip and run it to validate all HTML files in a specified directory. Use --help for a full list of options.

```bash
html5validator --root _build/
```

```bash
html5validator --help
```

--------------------------------

### CircleCI 2.0 Integration for HTML5 Validation

Source: https://github.com/svenkreiss/html5validator/blob/main/README.rst

Set up HTML5 validation in CircleCI 2.0 using a `circle.yml` file. This example shows installing Java, checking out code, installing dependencies, and running the validator.

```yaml
version: 2
jobs:
  test-3.6:
    docker:
      - image: python:3.6-stretch
    steps:
      - run:
          name: install Java
          command: apt-get update && apt-get install -y openjdk-8-jre
      - checkout
      - run:
          name: install
          command: pip install '.[test]'
      - run:
          name: generate html
          working_directory: test/example_site
```

--------------------------------

### Start the standalone web server

Source: https://github.com/svenkreiss/html5validator/blob/main/vnujar/README.md

Launch the built-in Jetty server to host the validation service on a specified port.

```bash
java -cp ~/vnu.jar              nu.validator.servlet.Main 8888
```

```bash
vnu-runtime-image/bin/java      nu.validator.servlet.Main 8888
```

```bash
vnu-runtime-image\bin\java.exe  nu.validator.servlet.Main 8888
```

--------------------------------

### Install Nu Html Checker via Package Managers

Source: https://github.com/svenkreiss/html5validator/blob/main/vnujar/README.md

Commands to install the validator using common package managers.

```bash
npm install vnu-jar
```

```bash
brew install vnu
```

```bash
pip install html5validator
```

--------------------------------

### Install html5validator with pip

Source: https://context7.com/svenkreiss/html5validator/llms.txt

Install the html5validator package using pip. Ensure you have Python 3.6+ installed.

```bash
pip install html5validator
```

--------------------------------

### Servlet Container Log Output

Source: https://github.com/svenkreiss/html5validator/blob/main/vnujar/README.md

Example log entry indicating successful deployment of the vnu.war file.

```text
May 7, 2014 4:42:04 PM org.apache.catalina.startup.HostConfig deployWAR
INFO: Deploying web application archive /var/lib/tomcat7/webapps/vnu.war
```

--------------------------------

### Start Checker Python Script

Source: https://github.com/svenkreiss/html5validator/blob/main/vnujar/README.md

Starts the HTML5 validator checker script using Python. The 'all' argument builds, tests, and runs the checker.

```bash
python ./checker.py all
```

--------------------------------

### CircleCI Integration

Source: https://context7.com/svenkreiss/html5validator/llms.txt

Set up CircleCI 2.0 to perform HTML5 validation as part of your CI pipeline. This example includes installing Java and the validator, building the site, and then validating.

```yaml
# .circleci/config.yml
version: 2.1

jobs:
  validate-html:
    docker:
      - image: cimg/python:3.10
    steps:
      - checkout
      - run:
          name: Install Java
          command: |
            sudo apt-get update
            sudo apt-get install -y openjdk-11-jre
      - run:
          name: Install html5validator
          command: pip install html5validator
      - run:
          name: Build site
          command: make build
      - run:
          name: Validate HTML
          command: html5validator --root ./output/ --also-check-css

workflows:
  version: 2
  build-and-validate:
    jobs:
      - validate-html
```

--------------------------------

### Bind Address Example

Source: https://github.com/svenkreiss/html5validator/blob/main/vnujar/README.md

Example of setting the nu.validator.servlet.bind-address Java system property to bind the validator service to a specific IP address.

```bash
-Dnu.validator.servlet.bind-address=127.0.0.1
```

--------------------------------

### Configure Severity Level Property

Source: https://github.com/svenkreiss/html5validator/blob/main/vnujar/README.md

Example of setting the severity level property via command line.

```bash
java -Dnu.validator.client.level=error -jar ~/vnu.jar FILE.html
```

--------------------------------

### Socket Timeout Example

Source: https://github.com/svenkreiss/html5validator/blob/main/vnujar/README.md

Example of setting the nu.validator.servlet.socket-timeout Java system property to specify the socket timeout in milliseconds.

```bash
-Dnu.validator.servlet.socket-timeout=5000
```

--------------------------------

### Get vnu.jar Help Output

Source: https://context7.com/svenkreiss/html5validator/llms.txt

Execute vnu.jar directly using the run_vnu method to retrieve its help information.

```python
from html5validator import Validator

validator = Validator()

# Get vnu.jar help
help_output, stderr = validator.run_vnu(['--help'])
print(help_output)
```

--------------------------------

### Install Specific HTML5 Validator Version

Source: https://github.com/svenkreiss/html5validator/blob/main/README.rst

Install a particular version of the html5validator package using pip. Replace '<version number>' with the desired version.

```bash
pip install html5validator==<version number>
```

--------------------------------

### Run Tests with nosetests

Source: https://github.com/svenkreiss/html5validator/blob/main/html5validator/tests/README.rst

Execute the project's tests directly using the nosetests command. Ensure nosetests is installed in your environment.

```bash
nosetests tests
```

--------------------------------

### GitHub Actions HTML5 Validator Example

Source: https://github.com/svenkreiss/html5validator/blob/main/README.rst

Integrate the html5validator GitHub Action into your workflow to automatically check HTML files. This example targets the 'html/' directory.

```yaml
- name: HTML5 Validator
  uses: Cyb3r-Jak3/html5validator-action@master
  with:
    root: html/
```

--------------------------------

### Set JAVA_HOME Environment Variable

Source: https://github.com/svenkreiss/html5validator/blob/main/vnujar/README.md

Sets the JAVA_HOME environment variable, essential for building and running Java-based projects. Examples for Ubuntu/MacOS provided.

```bash
export JAVA_HOME=/usr/lib/jvm/java-8-openjdk-amd64    <-- Ubuntu, etc.
```

```bash
export JAVA_HOME=$(/usr/libexec/java_home)            <-- MacOS
```

--------------------------------

### HTML5 Validator with Multiple Ignores

Source: https://github.com/svenkreiss/html5validator/blob/main/README.rst

Example command to run html5validator while ignoring specific regular expression patterns. Useful for handling known issues or framework-specific attributes.

```bash
html5validator --root tests/multiple_ignores/ --ignore-re 'Attribute "ng-[a-z-]+" not allowed' 'Start tag seen without seeing a doctype first'
```

--------------------------------

### TravisCI Configuration for Java Projects

Source: https://github.com/svenkreiss/html5validator/blob/main/README.rst

Set up HTML5 validation for your Java project in TravisCI. This configuration requires Java 8 and installs the validator using pip.

```yaml
language: java
jdk:
 - oraclejdk8  # vnu.jar requires Java 8

branches:
  only:
    - gh-pages

install:
 - pip install --user html5validator

script: html5validator --root _build/
```

--------------------------------

### GitLab CI HTML Test Configuration

Source: https://github.com/svenkreiss/html5validator/blob/main/README.rst

Use the official html5validator Docker image in GitLab CI for automated HTML testing. This example validates the 'public/' directory and checks CSS, outputting in text format.

```yaml
html_test:
  stage: html_test
  image: cyb3rjak3/html5validator:latest
  script:
    - html5validator --root public/ --also-check-css --format text
```

--------------------------------

### TravisCI Configuration for Python Projects

Source: https://github.com/svenkreiss/html5validator/blob/main/README.rst

Integrate HTML5 validation into your Python project's TravisCI build. Ensure Java 8 is installed as it's required by vnu.jar.

```yaml
language: python
python:
 - "2.7"
addons:
  apt:
    packages:
      - openjdk-8-jre  # install Java8 as required by vnu.jar

branches:
  only:
    - gh-pages

install:
 - pip install html5validator

script: html5validator --root _build/
```

--------------------------------

### Travis CI Integration

Source: https://context7.com/svenkreiss/html5validator/llms.txt

Configure Travis CI to automatically validate HTML files on every push for Python projects. Requires Java JRE installation.

```yaml
# .travis.yml
language: python
python:
  - "3.9"

addons:
  apt:
    packages:
      - openjdk-8-jre

install:
  - pip install html5validator

script:
  - html5validator --root _build/
```

--------------------------------

### GitHub Actions - Dedicated Action

Source: https://context7.com/svenkreiss/html5validator/llms.txt

Utilize a dedicated GitHub Action for html5validator to simplify integration into workflows. This approach abstracts away the setup steps.

```yaml
# Alternative: Use the dedicated GitHub Action
jobs:
  validate:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - name: HTML5 Validator
        uses: Cyb3r-Jak3/html5validator-action@master
        with:
          root: public/
          css: true
```

--------------------------------

### CircleCI 1.0 Integration for HTML5 Validation

Source: https://github.com/svenkreiss/html5validator/blob/main/README.rst

Integrate HTML5 validation into CircleCI 1.0 by configuring the `circle.yml` file to install the validator and run checks on the build output.

```yaml
machine:
  java:
    version: openjdk8
dependencies:
  pre:
    - sudo pip install html5validator
test:
  override:
    - html5validator --root _build/
```

--------------------------------

### GitHub Actions - Basic Validation

Source: https://context7.com/svenkreiss/html5validator/llms.txt

Integrate html5validator into a GitHub Actions workflow to automatically validate HTML files on push or pull requests. Requires Java and Python setup.

```yaml
# .github/workflows/validate.yml
name: HTML5 Validation

on: [push, pull_request]

jobs:
  validate:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3

      - name: Set up Python
        uses: actions/setup-python@v4
        with:
          python-version: '3.10'

      - name: Set up Java
        uses: actions/setup-java@v3
        with:
          distribution: 'temurin'
          java-version: '11'

      - name: Install html5validator
        run: pip install html5validator

      - name: Validate HTML
        run: html5validator --root ./public/ --also-check-css --format text
```

--------------------------------

### Run Tests with setup.py

Source: https://github.com/svenkreiss/html5validator/blob/main/html5validator/tests/README.rst

Execute the project's tests using the setup.py script. This is a standard method for running tests in Python projects.

```bash
python setup.py test
```

--------------------------------

### CLI Usage and Options

Source: https://github.com/svenkreiss/html5validator/blob/main/vnujar/README.md

Documentation for invoking the validator via command line and available configuration flags.

```APIDOC
## CLI Usage

### Description
Run the validator to check documents for compliance. The tool can be invoked via the runtime image or a JAR file.

### Usage
- Linux/macOS: `vnu-runtime-image/bin/vnu OPTIONS FILES`
- Windows: `vnu-runtime-image\bin\vnu.bat OPTIONS FILES`
- Java: `java -jar ~/vnu.jar OPTIONS FILES`

### Options
- **--errors-only** - Report only error-level messages.
- **--Werror** - Exit non-zero if warnings are encountered.
- **--exit-zero-always** - Exit zero even if errors are reported.
- **--stdout** - Report messages to stdout instead of stderr.
- **--asciiquotes** - Use ASCII quotes instead of Unicode smart quotes.
- **--format** (gnu|xml|json|text) - Specify output format.
- **--css** - Check documents as CSS.
- **--svg** - Check documents as SVG.
- **--html** - Check documents as HTML.
```

--------------------------------

### CLI Configuration Options

Source: https://github.com/svenkreiss/html5validator/blob/main/vnujar/README.md

A collection of command-line flags used to configure the behavior of the html5validator tool.

```APIDOC
## CLI Options

### --filterfile _FILENAME_
- **Description**: Specifies a file containing regular expressions to filter out error or warning messages. Each line is a regex or a comment starting with #.

### --filterpattern _REGEXP_
- **Description**: Specifies a single regular expression to filter out error or warning messages. Use '|' to OR multiple patterns.

### --format _format_
- **Description**: Specifies the output format for results.
- **Values**: "gnu", "xml", "json", "text"

### --skip-non-css / --css
- **Description**: --skip-non-css checks documents as CSS but skips non-css extensions. --css forces all documents to be checked as CSS.

### --skip-non-svg / --svg
- **Description**: --skip-non-svg checks documents as SVG but skips non-svg extensions. --svg forces all documents to be checked as SVG.

### --skip-non-html / --html
- **Description**: --skip-non-html skips documents without html/htm/xhtml/xht extensions. --html forces xhtml/xht to be parsed as HTML.

### --also-check-css / --also-check-svg
- **Description**: Enables checking of CSS or SVG documents in addition to HTML documents.

### --user-agent _USER_AGENT_
- **Description**: Sets the User-Agent header for HTTP/HTTPS requests.

### --no-langdetect
- **Description**: Disables language detection and html[lang] attribute checking.

### --no-stream
- **Description**: Forces buffered mode instead of streaming mode for parsing.

### --verbose
- **Description**: Enables verbose output, printing filenames to stdout.

### --version / --help
- **Description**: Displays version information or detailed usage help.
```

--------------------------------

### HTML5 Validator Command Line Options

Source: https://github.com/svenkreiss/html5validator/blob/main/README.rst

This displays the usage information for the html5validator command-line tool, detailing all available arguments and their functions.

```text
usage: html5validator [-h] [--root ROOT] [--match MATCH [MATCH ...]]
                      [--blacklist [BLACKLIST ...]] [--show-warnings]
                      [--no-langdetect] [--no-vnu-stdout] [--no-asciiquotes]
                      [--format {gnu,xml,json,text}]
                      [--ignore [IGNORE ...]] [--ignore-re [IGNORE_RE ...]]
                      [--config CONFIG] [-l] [-ll] [-lll] [--log LOG]
                      [--log-file LOG_FILE] [--version]
                      [files ...]

[v0.4.2] Command line tool for HTML5 validation. Return code is 0 for valid
HTML5. Arguments that are unknown to html5validator
 are passed as arguments to `vnu.jar`.

positional arguments:
  files                 specify files to check

optional arguments:
  -h, --help            show this help message and exit
  --root ROOT           start directory to search for files to validate
  --match MATCH [MATCH ...]
                        match file pattern in search (default: "*.html" or
                        "*.html *.css" if --also-check-css is used)
  --blacklist [BLACKLIST ...]
                        directory names to skip in search
  --show-warnings       show warnings and count them as errors
  --no-langdetect       disable language detection
  --no-vnu-stdout       do not use --stdout with vnu.jar
  --no-asciiquotes      do not use --asciiquotes with vnu.jar
  --format {gnu,xml,json,text}
                        output format
  --ignore [IGNORE ...]
                        ignore messages containing the given strings
  --ignore-re [IGNORE_RE ...]
                        regular expression of messages to ignore
  --config CONFIG       Path to a config file for options
  -l                    run on larger files: sets Java stack size to 2048k
  -ll                   run on larger files: sets Java stack size to 8192k
  -lll                  run on larger files: sets Java stack size to 32768k
  --log LOG             log level: DEBUG, INFO or WARNING (default: WARNING)
  --log-file LOG_FILE   Name for log file. If no name supplied then no log
                        file will be created
  --version             show program's version number and exit
```

--------------------------------

### Output Format Options

Source: https://context7.com/svenkreiss/html5validator/llms.txt

Select from various output formats for integration with different tools and parsers. The default is GNU format.

```bash
# GNU format (default) - one error per line
html5validator --root _build/ --format gnu
# Output: ./index.html:10.5-10.25: error: Element "div" not allowed here.
```

```bash
# JSON format - machine-readable output
html5validator --root _build/ --format json
# Output: {"messages":[{"type":"error","url":"file:./index.html",...}]}
```

```bash
# XML format
html5validator --root _build/ --format xml
```

```bash
# Text format - human-readable multiline
html5validator --root _build/ --format text
```

--------------------------------

### Run Nu Html Checker via Docker

Source: https://github.com/svenkreiss/html5validator/blob/main/vnujar/README.md

Execute the validator as a service using the latest Docker image.

```bash
docker run -it --rm -p 8888:8888 validator/validator:latest
```

--------------------------------

### Navigate to Validator Directory

Source: https://github.com/svenkreiss/html5validator/blob/main/vnujar/README.md

Changes the current directory to the cloned validator repository.

```bash
cd validator
```

--------------------------------

### Checker Script Help

Source: https://github.com/svenkreiss/html5validator/blob/main/vnujar/README.md

Displays the help message for the checker Python script, listing available command-line options and build targets.

```bash
python ./checker.py --help
```

--------------------------------

### Invoke Local HTTP Client

Source: https://github.com/svenkreiss/html5validator/blob/main/vnujar/README.md

Commands to run the validator client against a local HTTP service.

```bash
java -cp ~/vnu.jar nu.validator.client.HttpClient FILE.html...
```

```bash
vnu-runtime-image/bin/java nu.validator.client.HttpClient FILE.html...
```

--------------------------------

### Find Multiple File Types

Source: https://context7.com/svenkreiss/html5validator/llms.txt

Use the all_files function to find files matching multiple patterns (e.g., HTML, CSS, SVG) within a directory, while excluding specified build directories.

```python
# Find multiple file types
all_web_files = all_files(
    directory='./src',
    match=['*.html', '*.css', '*.svg'],
    blacklist=['dist', 'build']
)

# Validate found files
validator = Validator(errors_only=True)
error_count = validator.validate(html_files)
```

--------------------------------

### Configure Logging Level

Source: https://context7.com/svenkreiss/html5validator/llms.txt

Set the logging level for html5validator output. Available levels are DEBUG, INFO, and WARNING.

```bash
html5validator --root _build/ --log DEBUG
```

--------------------------------

### File Pattern Matching and Blacklisting

Source: https://context7.com/svenkreiss/html5validator/llms.txt

Use glob patterns to specify which files to match for validation and blacklist directories to exclude from the search.

```bash
# Match specific file patterns
html5validator --root src/ --match "*.html" "*.htm"
```

```bash
# Match HTML and CSS files
html5validator --root src/ --match "*.html" "*.css"
```

```bash
# Exclude directories from search
html5validator --root _build/ --blacklist node_modules vendor .git
```

```bash
# Combine patterns with blacklist
html5validator --root public/ --match "*.html" --blacklist drafts temp
```

--------------------------------

### Check documents from command line

Source: https://github.com/svenkreiss/html5validator/blob/main/vnujar/README.md

Validate one or more HTML files using the vnu binary or Java JAR.

```bash
vnu-runtime-image/bin/vnu      FILE.html FILE2.html FILE3.html...
```

```bash
vnu-runtime-image\bin\vnu.bat  FILE.html FILE2.html FILE3.html...
```

```bash
java -jar ~/vnu.jar            FILE.html FILE2.html FILE3.html...
```

--------------------------------

### HTTP Client Configuration Options

Source: https://github.com/svenkreiss/html5validator/blob/main/vnujar/README.md

The HTTP client supports various Java system properties to configure how documents are sent to and processed by the validator service.

```APIDOC
## HTTP Client Configuration

### Description
Configure the behavior of the `nu.validator.client.HttpClient` using Java system properties.

### Parameters
- **nu.validator.client.host** (string) - Optional - Hostname of the checker. Default: "127.0.0.1"
- **nu.validator.client.port** (integer) - Optional - Port of the checker. Default: "8888"
- **nu.validator.client.level** (string) - Optional - Severity level of messages. Possible values: "error"
- **nu.validator.client.parser** (string) - Optional - Parser to use. Default: "html" (or "xml" for .xhtml files)
- **nu.validator.client.charset** (string) - Optional - Encoding of the input document.

### Request Example
java -Dnu.validator.client.level=error -cp ~/vnu.jar nu.validator.client.HttpClient FILE.html
```

--------------------------------

### YAML Configuration File

Source: https://context7.com/svenkreiss/html5validator/llms.txt

Use a YAML configuration file to store validation options for reproducible builds. This allows for a centralized and version-controllable way to manage validator settings.

```yaml
# html5validator.yaml
root: ./public/
match:
  - "*.html"
  - "*.css"
blacklist:
  - node_modules
  - vendor
ignore_re:
  - 'Attribute "ng-[a-z-]+" not allowed'
  - 'Attribute "v-[a-z-]+" not allowed'
ignore:
  - 'Start tag seen without seeing a doctype first'
# Pass additional arguments to vnu.jar
vnu:
  - --also-check-css
```

```bash
html5validator --config html5validator.yaml
```

--------------------------------

### Run vnu.jar with Custom Arguments

Source: https://context7.com/svenkreiss/html5validator/llms.txt

Execute vnu.jar with custom arguments, such as specifying the output format and error filtering, and capture the standard output and error streams.

```python
stdout, stderr = validator.run_vnu([
    '--format',
    'json',
    '--errors-only',
    'index.html'
])
print(stdout)
```

--------------------------------

### Check Web URL

Source: https://github.com/svenkreiss/html5validator/blob/main/vnujar/README.md

Validate a document hosted at a specific URL.

```bash
vnu _URL_
```

```bash
example: vnu http://example.com/foo
```

--------------------------------

### HTML5 Validator Basic Usage

Source: https://github.com/svenkreiss/html5validator/blob/main/README.rst

Run the html5validator tool to check the HTML output of a Pelican site. The --root option specifies the directory containing the generated site.

```bash
html5validator --root test/example_site/output
```

--------------------------------

### Handle JavaNotFoundException in Python

Source: https://context7.com/svenkreiss/html5validator/llms.txt

Demonstrates how to catch the JavaNotFoundException when the validator environment lacks the required Java runtime.

```python
from html5validator import Validator, JavaNotFoundException

try:
    validator = Validator()
    error_count = validator.validate(['index.html'])
except JavaNotFoundException as e:
    print(f"Error: {e}")
    print("Please install Java 8 or later")
    exit(1)
```

--------------------------------

### Find HTML Files with all_files

Source: https://context7.com/svenkreiss/html5validator/llms.txt

Use the all_files helper function to locate all HTML files within a specified directory, excluding blacklisted directories and invisible files.

```python
from html5validator import Validator
from html5validator.validator import all_files

# Find all HTML files in a directory
html_files = all_files(
    directory='./public',
    match='*.html',
    blacklist=['node_modules', 'vendor'],
    skip_invisible=True
)
print(f"Found {len(html_files)} HTML files")
```

--------------------------------

### INFO Level Logging

Source: https://context7.com/svenkreiss/html5validator/llms.txt

Use INFO level logging to display file names being checked during validation.

```bash
html5validator --root _build/ --log INFO
```

--------------------------------

### Configure GitLab CI for HTML5 Validation

Source: https://context7.com/svenkreiss/html5validator/llms.txt

Defines a build and validation stage in .gitlab-ci.yml to automate HTML5 validation using the official Docker image.

```yaml
stages:
  - build
  - validate

build:
  stage: build
  script:
    - make build
  artifacts:
    paths:
      - public/

html_validate:
  stage: validate
  image: cyb3rjak3/html5validator:latest
  script:
    - html5validator --root public/ --also-check-css --format text
  dependencies:
    - build
```

--------------------------------

### Bind the server to a specific address

Source: https://github.com/svenkreiss/html5validator/blob/main/vnujar/README.md

Use the nu.validator.servlet.bind-address system property to specify the network interface for the service.

```bash
java -cp ~/vnu.jar \
    -Dnu.validator.servlet.bind-address=128.30.52.73 \
    nu.validator.servlet.Main 8888
```

```bash
vnu-runtime-image/bin/java \
    -Dnu.validator.servlet.bind-address=128.30.52.73 \
    nu.validator.servlet.Main 8888
```

```bash
vnu-runtime-image\bin\java.exe  \
    -Dnu.validator.servlet.bind-address=128.30.52.73 \
    nu.validator.servlet.Main 8888
```

--------------------------------

### Check standard input

Source: https://github.com/svenkreiss/html5validator/blob/main/vnujar/README.md

Pipe content directly into the validator using standard input.

```bash
vnu -
```

```bash
echo '<!doctype html><title>...' | vnu -
```

```bash
echo '<!doctype html><title>...' | java -jar ~/vnu.jar -
```

--------------------------------

### Checker Script Build and Test

Source: https://github.com/svenkreiss/html5validator/blob/main/vnujar/README.md

Executes both the build and test steps of the checker Python script.

```bash
python ./checker.py build  # test to build and test
```

--------------------------------

### TravisCI Configuration for User Pages

Source: https://github.com/svenkreiss/html5validator/blob/main/README.rst

Adapt the TravisCI configuration for user pages (e.g., username.github.io) by removing the branch restriction. HTML files are typically in the master branch for these repositories.

```yaml
branches:
  only:
    - gh-pages
```

--------------------------------

### Python API - all_files Function

Source: https://context7.com/svenkreiss/html5validator/llms.txt

A helper function to recursively find files in a directory based on match patterns and blacklists.

```APIDOC
## all_files Function

### Description
Finds files matching specific patterns in a directory, useful for preparing file lists for the Validator class.

### Parameters
- **directory** (string) - Required - The root directory to search.
- **match** (string/list) - Required - Glob pattern(s) to match files.
- **blacklist** (list) - Optional - Directories or files to exclude.
- **skip_invisible** (bool) - Optional - Whether to skip hidden files.

### Request Example
```python
from html5validator.validator import all_files
files = all_files(directory='./public', match='*.html', blacklist=['node_modules'])
```
```

--------------------------------

### Basic Command Line Validation

Source: https://context7.com/svenkreiss/html5validator/llms.txt

Validate all HTML files in a directory recursively. The tool returns exit code 0 for valid files or a non-zero value indicating the number of errors found (capped at 255).

```bash
# Validate all HTML files in the _build directory
html5validator --root _build/
```

```bash
html5validator index.html about.html contact.html
```

```bash
html5validator --root _build/ --log DEBUG
```

--------------------------------

### Write Logs to File

Source: https://context7.com/svenkreiss/html5validator/llms.txt

Configure html5validator to write logs to a specified file. This is useful for debugging validation issues.

```bash
html5validator --root _build/ --log DEBUG --log-file validation
```

--------------------------------

### HTML5 Validator for Specific Files

Source: https://github.com/svenkreiss/html5validator/blob/main/README.rst

Validate specific HTML files by listing them directly on the command line. This is useful for validating individual files or a small set.

```bash
html5validator file1.html file2.html
```

--------------------------------

### Clone Validator Repository

Source: https://github.com/svenkreiss/html5validator/blob/main/vnujar/README.md

Clones the HTML5 validator source code repository from GitHub using git.

```bash
git clone https://github.com/validator/validator.git
```

--------------------------------

### HTML5 Validator with Specific File Patterns

Source: https://github.com/svenkreiss/html5validator/blob/main/README.rst

Run html5validator on a specific list of files using glob patterns. This allows for targeted validation of HTML and CSS files.

```bash
html5validator --match *.html *.css
```

--------------------------------

### Python API - run_vnu Method

Source: https://context7.com/svenkreiss/html5validator/llms.txt

Execute the underlying vnu.jar directly with custom arguments.

```APIDOC
## run_vnu Method

### Description
Provides low-level access to the vnu.jar validator by passing a list of command-line arguments.

### Parameters
- **args** (list) - Required - List of command-line arguments for vnu.jar.

### Response
- **stdout** (string) - The standard output from the validator.
- **stderr** (string) - The standard error output from the validator.
```

--------------------------------

### Check directory contents

Source: https://github.com/svenkreiss/html5validator/blob/main/vnujar/README.md

Validate all documents within a specified directory path.

```bash
java -jar ~/vnu.jar            DIRECTORY_PATH
```

```bash
vnu-runtime-image/bin/vnu      DIRECTORY_PATH
```

```bash
vnu-runtime-image\bin\vnu.bat  DIRECTORY_PATH
```

--------------------------------

### HTML5 Validator with CSS Check and Text Format

Source: https://github.com/svenkreiss/html5validator/blob/main/README.rst

Validate HTML and CSS files within the 'public/' directory using the html5validator. The output is formatted as plain text.

```bash
html5validator --root public/ --also-check-css --format text
```

--------------------------------

### Show Warnings as Errors

Source: https://context7.com/svenkreiss/html5validator/llms.txt

Configure the validator to display warnings and count them as errors, which affects the exit code. The default behavior is to only show errors.

```bash
# Show warnings and treat them as errors (affects exit code)
html5validator --root _build/ --show-warnings
```

```bash
# Default behavior: only errors shown, warnings hidden
html5validator --root _build/
```

--------------------------------

### Checker Script Compile JAR

Source: https://github.com/svenkreiss/html5validator/blob/main/vnujar/README.md

Compiles the vnu.jar artifact using the checker Python script.

```bash
python ./checker.py jar
```

--------------------------------

### Set Docker Validator Java Options

Source: https://github.com/svenkreiss/html5validator/blob/main/vnujar/README.md

Runs the validator from Docker Hub with specific Java system properties set via the JAVA_TOOL_OPTIONS environment variable. Maps port 8888.

```bash
docker run -it --rm \
         -e JAVA_TOOL_OPTIONS=-Dnu.validator.client.asciiquotes=yes  \
         -p 8888:8888 \
         validator/validator
```

--------------------------------

### Faster JAR Compilation

Source: https://github.com/svenkreiss/html5validator/blob/main/vnujar/README.md

Compiles the vnu.jar artifact more quickly by performing a shallow update, downloading dependencies, and then compiling.

```bash
python ./checker.py update-shallow && \
    python ./checker.py dldeps && \
    python ./checker.py jar
```

--------------------------------

### Checker Script Build Only

Source: https://github.com/svenkreiss/html5validator/blob/main/vnujar/README.md

Executes only the build step of the checker Python script.

```bash
python ./checker.py build
```

--------------------------------

### Check CSS and SVG Files

Source: https://github.com/svenkreiss/html5validator/blob/main/README.rst

Validate CSS and SVG files in addition to HTML. The --also-check-css flag enables CSS validation, while --skip-non-css can be used to check only CSS files.

```bash
html5validator --root _build/ --also-check-css
```

```bash
# checking only CSS
html5validator --root _build/ --skip-non-css
```

--------------------------------

### Adjust thread stack size

Source: https://github.com/svenkreiss/html5validator/blob/main/vnujar/README.md

Use the -Xss option if the checker encounters a StackOverflowError.

```bash
java -Xss512k -cp ~/vnu.jar nu.validator.servlet.Main 8888
```

```bash
vnu-runtime-image/bin/java -Xss512k -m vnu/nu.validator.servlet.Main 8888
```

--------------------------------

### Suppress Warning Messages

Source: https://github.com/svenkreiss/html5validator/blob/main/vnujar/README.md

Configure the client to report only error-level messages.

```bash
java -Dnu.validator.client.level=error \
       -cp ~/vnu.jar nu.validator.client.HttpClient FILE.html...
```

```bash
vnu-runtime-image/bin/java -Dnu.validator.client.level=error \
       -cp ~/vnu.jar nu.validator.client.HttpClient FILE.html...
```

--------------------------------

### Python Validation with Options

Source: https://context7.com/svenkreiss/html5validator/llms.txt

Configure the Validator class with various options for detailed control over validation behavior, including error filtering and output format.

```python
validator = Validator(
    errors_only=True,           # Only show errors, not warnings
    detect_language=True,       # Enable language detection
    format='json',              # Output format: gnu, json, xml, text
    stack_size=2048,            # Java stack size in KB
    ignore=['doctype'],         # Ignore errors containing these strings
    ignore_re=[r'ng-[a-z-]+'],  # Ignore errors matching these patterns
    vnu_args=['--also-check-css', '--stdout']  # Additional vnu.jar arguments
)

# Validate files
files = ['public/index.html', 'public/about.html', 'public/style.css']
error_count = validator.validate(files)

if error_count == 0:
    print("All files are valid!")
else:
    print(f"Validation failed with {error_count} errors")
```

--------------------------------

### Bind Checker to Specific Address

Source: https://github.com/svenkreiss/html5validator/blob/main/vnujar/README.md

Runs the checker script, binding it to a specific IP address to ensure reachability, especially in future releases.

```bash
python ./checker.py --bind-address=128.30.52.73 all
```

--------------------------------

### Invoke Remote HTTP Client

Source: https://github.com/svenkreiss/html5validator/blob/main/vnujar/README.md

Commands to send documents to a remote validator instance using specific host and port properties.

```bash
java -cp ~/vnu.jar -Dnu.validator.client.port=80 \
    -Dnu.validator.client.host=html5.validator.nu \
    nu.validator.client.HttpClient FILE.html...
```

```bash
vnu-runtime-image/bin/java -Dnu.validator.client.port=80 \
    -Dnu.validator.client.host=html5.validator.nu \
    nu.validator.client.HttpClient FILE.html...
```

--------------------------------

### Validate CSS and SVG Files

Source: https://context7.com/svenkreiss/html5validator/llms.txt

Enable validation for CSS and SVG files alongside HTML, or configure to validate only specific file types.

```bash
# Validate both HTML and CSS files
html5validator --root _build/ --also-check-css
```

```bash
# Validate both HTML and SVG files
html5validator --root _build/ --also-check-svg
```

```bash
# Validate only CSS files (skip HTML)
html5validator --root _build/ --skip-non-css
```

```bash
# Validate only SVG files (skip HTML)
html5validator --root _build/ --skip-non-svg
```

--------------------------------

### Adjust thread stack size

Source: https://github.com/svenkreiss/html5validator/blob/main/vnujar/README.md

Use the -Xss option if a StackOverflowError occurs during validation.

```bash
java -Xss512k -jar ~/vnu.jar ...
```

```bash
vnu-runtime-image/bin/java -Xss512k \
    -m vnu/nu.validator.client.SimpleCommandLineValidator ...
```

--------------------------------

### Bind Docker Validator to Specific Address

Source: https://github.com/svenkreiss/html5validator/blob/main/vnujar/README.md

Runs the validator from Docker Hub, binding it to a specific IP address on the host machine. Maps port 8888.

```bash
docker run -it --rm -p 128.30.52.73:8888:8888 validator/validator:latest
```

--------------------------------

### Run Specific Docker Validator Version

Source: https://github.com/svenkreiss/html5validator/blob/main/vnujar/README.md

Pulls and runs a specific version of the validator from Docker Hub, identified by a tag. Maps port 8888.

```bash
docker run -it --rm -p 8888:8888 validator/validator:17.11.1
```

--------------------------------

### Set Docker Validator Timeouts

Source: https://github.com/svenkreiss/html5validator/blob/main/vnujar/README.md

Runs the validator from Docker Hub with custom connection and socket timeouts using environment variables. Maps port 8888.

```bash
docker run -it --rm \
         -e CONNECTION_TIMEOUT_SECONDS=15 \
         -e SOCKET_TIMEOUT_SECONDS=15 \
         -p 8888:8888 \
         validator/validator
```

--------------------------------

### Handling Large Files with Java Stack Size

Source: https://context7.com/svenkreiss/html5validator/llms.txt

Increase the Java stack size for validating large HTML files that might cause a StackOverflowError. Options range from small to very large stack sizes.

```bash
# Set Java stack size to 2048k
html5validator --root _build/ -l
```

```bash
# Set Java stack size to 8192k
html5validator --root _build/ -ll
```

```bash
# Set Java stack size to 32768k (for very large files)
html5validator --root _build/ -lll
```

--------------------------------

### Disable Inbound Size Limit Filter in web.xml

Source: https://github.com/svenkreiss/html5validator/blob/main/vnujar/README.md

Comment out the inbound-size-limit-filter in the web.xml file to modify servlet filter configuration.

```xml
<!--
  <filter>
      <filter-name>inbound-size-limit-filter</filter-name>
      <filter-class>nu.validator.servlet.InboundSizeLimitFilter</filter-class>
  </filter>
  <filter-mapping>
      <filter-name>inbound-size-limit-filter</filter-name>
      <url-pattern>/*</url-pattern>
  </filter-mapping>
-->
```

--------------------------------

### Basic Python Validation

Source: https://context7.com/svenkreiss/html5validator/llms.txt

Perform basic HTML validation using the Validator class in Python. Counts and prints the number of errors found.

```python
from html5validator import Validator

# Basic validation
validator = Validator()
error_count = validator.validate(['index.html', 'about.html'])
print(f"Found {error_count} errors")
```

--------------------------------

### Checker Script Run Only

Source: https://github.com/svenkreiss/html5validator/blob/main/vnujar/README.md

Executes only the run step of the checker Python script.

```bash
python ./checker.py run
```

--------------------------------

### Docker Compose Service Definition

Source: https://github.com/svenkreiss/html5validator/blob/main/vnujar/README.md

Defines a 'vnu' service for Docker Compose, using the validator image and mapping port 8888. Uses host network mode.

```yaml
version: '2' services:
  vnu:
    image: validator/validator ports:
    - "8888:8888"
  network_mode: "host" #so "localhost" refers to the host machine.
```

--------------------------------

### Filter directory validation

Source: https://github.com/svenkreiss/html5validator/blob/main/vnujar/README.md

Validate directory contents with specific file extension filtering or format checks.

```bash
vnu --skip-non-html DIRECTORY_PATH
```

```bash
vnu --css DIRECTORY_PATH
```

```bash
vnu --skip-non-css DIRECTORY_PATH
```

```bash
vnu --also-check-css DIRECTORY_PATH
```

```bash
vnu --svg DIRECTORY_PATH
```

```bash
vnu --skip-non-svg DIRECTORY_PATH
```

```bash
vnu --also-check-svg DIRECTORY_PATH
```

--------------------------------

### Ignoring Specific Errors

Source: https://context7.com/svenkreiss/html5validator/llms.txt

Filter validation errors using exact string matching or regular expressions. This is useful for suppressing known issues, such as those generated by frameworks like AngularJS.

```bash
# Ignore errors containing exact string
html5validator --root _build/ --ignore "Start tag seen without seeing a doctype first"
```

```bash
# Ignore errors matching regex pattern (useful for AngularJS ng-* attributes)
html5validator --root _build/ --ignore-re 'Attribute "ng-[a-z-]+" not allowed'
```

```bash
# Multiple ignore patterns
html5validator --root _build/ \
  --ignore-re 'Attribute "ng-[a-z-]+" not allowed' \
  --ignore-re 'Attribute "data-[a-z-]+" not allowed'
```

```bash
# Combine exact and regex ignores
html5validator --root _build/ \
  --ignore "Element \"style\" not allowed as child of element \"body\"" \
  --ignore-re 'Attribute "v-[a-z-]+" not allowed'
```

--------------------------------

### HTML5 Validator with Angular.js Ignore Pattern

Source: https://github.com/svenkreiss/html5validator/blob/main/README.rst

Use the --ignore-re option to exclude specific patterns from validation errors, such as Angular.js attributes, which are not standard HTML.

```bash
html5validator --root tests/multiple_ignores/ --ignore-re 'Attribute "ng-[a-z-]+" not allowed'
```

--------------------------------

### Python API - Validator Class

Source: https://context7.com/svenkreiss/html5validator/llms.txt

The Validator class allows for programmatic HTML validation within Python scripts, supporting various configuration options and output formats.

```APIDOC
## Validator Class

### Description
Use the Validator class to perform HTML validation on a list of files with customizable settings.

### Parameters
#### Constructor Options
- **errors_only** (bool) - Optional - Only show errors, not warnings.
- **detect_language** (bool) - Optional - Enable language detection.
- **format** (string) - Optional - Output format: gnu, json, xml, text.
- **stack_size** (int) - Optional - Java stack size in KB.
- **ignore** (list) - Optional - List of strings to ignore in error messages.
- **ignore_re** (list) - Optional - List of regex patterns to ignore in error messages.
- **vnu_args** (list) - Optional - Additional arguments passed to vnu.jar.

### Request Example
```python
from html5validator import Validator
validator = Validator(errors_only=True, format='json')
error_count = validator.validate(['index.html'])
```
```
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