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A file .lycheeignore can be defined at the root of the repository to ignore some urls.

Each line can contain Regular Expressions or glob format.

Example with glob, regex and full url:*

lychee documentation

lychee - GitHub

Configuration in MegaLinter

Variable Description Default value
SPELL_LYCHEE_ARGUMENTS User custom arguments to add in linter CLI call
Ex: -s --foo "bar"
SPELL_LYCHEE_COMMAND_REMOVE_ARGUMENTS User custom arguments to remove from command line before calling the linter
Ex: -s --foo "bar"
SPELL_LYCHEE_FILTER_REGEX_INCLUDE Custom regex including filter
Ex: (src\|lib)
Include every file
SPELL_LYCHEE_FILTER_REGEX_EXCLUDE Custom regex excluding filter
Ex: (test\|examples)
Exclude no file
SPELL_LYCHEE_CLI_LINT_MODE Override default CLI lint mode
- file: Calls the linter for each file
- list_of_files: Call the linter with the list of files as argument
- project: Call the linter from the root of the project
SPELL_LYCHEE_FILE_EXTENSIONS Allowed file extensions. "*" matches any extension, "" matches empty extension. Empty list excludes all files
Ex: [".py", ""]
[".md", ".mdx", ".markdown", ".html", ".htm", ".rst", ".txt", ".json", ".jsonc", ".json5", ".yaml", ".yml"]
SPELL_LYCHEE_FILE_NAMES_REGEX File name regex filters. Regular expression list for filtering files by their base names using regex full match. Empty list includes all files
Ex: ["Dockerfile(-.+)?", "Jenkinsfile"]
Include every file
SPELL_LYCHEE_PRE_COMMANDS List of bash commands to run before the linter None
SPELL_LYCHEE_POST_COMMANDS List of bash commands to run after the linter None
SPELL_LYCHEE_UNSECURED_ENV_VARIABLES List of env variables explicitly not filtered before calling SPELL_LYCHEE and its pre/post commands None
SPELL_LYCHEE_CONFIG_FILE lychee configuration file nameUse LINTER_DEFAULT to let the linter find it lychee.toml
SPELL_LYCHEE_RULES_PATH Path where to find linter configuration file Workspace folder, then MegaLinter default rules
SPELL_LYCHEE_DISABLE_ERRORS Run linter but consider errors as warnings false
SPELL_LYCHEE_DISABLE_ERRORS_IF_LESS_THAN Maximum number of errors allowed 0
SPELL_LYCHEE_CLI_EXECUTABLE Override CLI executable ['lychee']

MegaLinter Flavours

This linter is available in the following flavours

Flavor Description Embedded linters Info
all Default MegaLinter Flavor 121 Docker Image Size (tag) Docker Pulls
c_cpp Optimized for pure C/C++ projects 55 Docker Image Size (tag) Docker Pulls
cupcake MegaLinter for the most commonly used languages 85 Docker Image Size (tag) Docker Pulls
documentation MegaLinter for documentation projects 51 Docker Image Size (tag) Docker Pulls
dotnet Optimized for C, C++, C# or VB based projects 64 Docker Image Size (tag) Docker Pulls
dotnetweb Optimized for C, C++, C# or VB based projects with JS/TS 73 Docker Image Size (tag) Docker Pulls
go Optimized for GO based projects 53 Docker Image Size (tag) Docker Pulls
java Optimized for JAVA based projects 55 Docker Image Size (tag) Docker Pulls
javascript Optimized for JAVASCRIPT or TYPESCRIPT based projects 60 Docker Image Size (tag) Docker Pulls
php Optimized for PHP based projects 54 Docker Image Size (tag) Docker Pulls
python Optimized for PYTHON based projects 62 Docker Image Size (tag) Docker Pulls
ruby Optimized for RUBY based projects 51 Docker Image Size (tag) Docker Pulls
rust Optimized for RUST based projects 51 Docker Image Size (tag) Docker Pulls
salesforce Optimized for Salesforce based projects 55 Docker Image Size (tag) Docker Pulls
swift Optimized for SWIFT based projects 51 Docker Image Size (tag) Docker Pulls
terraform Optimized for TERRAFORM based projects 55 Docker Image Size (tag) Docker Pulls

Behind the scenes

How are identified applicable files

  • File extensions: .md, .mdx, .markdown, .html, .htm, .rst, .txt, .json, .jsonc, .json5, .yaml, .yml

How the linting is performed

  • lychee is called once with the list of files as arguments (list_of_files CLI lint mode)

Example calls

lychee --format detailed --no-progress info.txt test.html
lychee --format detailed --no-progress
lychee --format detailed --no-progress test.html info.txt
lychee --format detailed --no-progress --offline path/to/directory
lychee --format detailed --no-progress
lychee --format detailed --no-progress "~/projects/big_project/**/README.*"
lychee --format detailed --no-progress --glob-ignore-case --verbose "~/projects/**/[r]eadme.*"

Help content

A fast, async link checker

Finds broken URLs and mail addresses inside Markdown, HTML, `reStructuredText`, websites and more!

Usage: lychee [OPTIONS] <inputs>...

          The inputs (where to get links to check from). These can be: files (e.g. ``), file globs (e.g. `"~/git/*/"`), remote URLs (e.g. ``) or standard input (`-`). NOTE: Use `--` to separate inputs from options that allow multiple arguments

  -c, --config <CONFIG_FILE>
          Configuration file to use

          [default: lychee.toml]

  -v, --verbose...
          Set verbosity level; more output per occurrence (e.g. `-v` or `-vv`)

  -q, --quiet...
          Less output per occurrence (e.g. `-q` or `-qq`)

  -n, --no-progress
          Do not show progress bar.
          This is recommended for non-interactive shells (e.g. for continuous integration)

          Use request cache stored on disk at `.lycheecache`

      --max-cache-age <MAX_CACHE_AGE>
          Discard all cached requests older than this duration

          [default: 1d]

          Don't perform any link checking. Instead, dump all the links extracted from inputs that would be checked

      --archive <ARCHIVE>
          Specify the use of a specific web archive. Can be used in combination with `--suggest`

          [possible values: wayback]

          Suggest link replacements for broken links, using a web archive. The web archive can be specified with `--archive`

  -m, --max-redirects <MAX_REDIRECTS>
          Maximum number of allowed redirects

          [default: 5]

      --max-retries <MAX_RETRIES>
          Maximum number of retries per request

          [default: 3]

      --max-concurrency <MAX_CONCURRENCY>
          Maximum number of concurrent network requests

          [default: 128]

  -T, --threads <THREADS>
          Number of threads to utilize. Defaults to number of cores available to the system

  -u, --user-agent <USER_AGENT>
          User agent

          [default: lychee/0.13.0]

  -i, --insecure
          Proceed for server connections considered insecure (invalid TLS)

  -s, --scheme <SCHEME>
          Only test links with the given schemes (e.g. http and https)

          Only check local files and block network requests

      --include <INCLUDE>
          URLs to check (supports regex). Has preference over all excludes

      --exclude <EXCLUDE>
          Exclude URLs and mail addresses from checking (supports regex)

      --exclude-file <EXCLUDE_FILE>
          Deprecated; use `--exclude-path` instead

      --exclude-path <EXCLUDE_PATH>
          Exclude file path from getting checked

  -E, --exclude-all-private
          Exclude all private IPs from checking.
          Equivalent to `--exclude-private --exclude-link-local --exclude-loopback`

          Exclude private IP address ranges from checking

          Exclude link-local IP address range from checking

          Exclude loopback IP address range and localhost from checking

          Exclude all mail addresses from checking

      --remap <REMAP>
          Remap URI matching pattern to different URI

      --header <HEADER>
          Custom request header

  -a, --accept <ACCEPT>
          Comma-separated list of accepted status codes for valid links

  -t, --timeout <TIMEOUT>
          Website timeout in seconds from connect to response finished

          [default: 20]

  -r, --retry-wait-time <RETRY_WAIT_TIME>
          Minimum wait time in seconds between retries of failed requests

          [default: 1]

  -X, --method <METHOD>
          Request method

          [default: get]

  -b, --base <BASE>
          Base URL or website root directory to check relative URLs e.g. or `/path/to/public`

      --basic-auth <BASIC_AUTH>
          Basic authentication support. E.g. `username:password`

      --github-token <GITHUB_TOKEN>
          GitHub API token to use when checking links, to avoid rate limiting

          [env: GITHUB_TOKEN]

          Skip missing input files (default is to error if they don't exist)

          Find links in verbatim sections like `pre`- and `code` blocks

          Ignore case when expanding filesystem path glob inputs

  -o, --output <OUTPUT>
          Output file of status report

  -f, --format <FORMAT>
          Output format of final status report (compact, detailed, json, markdown)

          [default: compact]

          When HTTPS is available, treat HTTP links as errors

  -h, --help
          Print help (see a summary with '-h')

  -V, --version
          Print version

Installation on mega-linter Docker image

  • Dockerfile commands :
FROM lycheeverse/lychee:latest-alpine as lychee
COPY --link --from=lychee /usr/local/bin/lychee /usr/bin/