CLI

Reference page

For the complete module reference (all exports, CLI options, exit codes), see the parser-cli reference.

The parser CLI parses HTML and Markdown files, runs LexQuery patterns, and serializes parse trees back to markup.

Package: @lanexio/parser-cli
Runtime: Node.js only.

Install

pnpm add -g @lanexio/parser-cli

Subcommands

Subcommand	Description
parser parse <file>	Parse a file and print the tree or JSON.
parser query <pattern> <file>	Run a LexQuery pattern and print matching nodes.
parser serialize <file>	Parse and re-serialize to HTML or Markdown source.

parse

parser parse index.html
parser parse README.md
parser parse --grammar html --output json < input.html

Options

Flag	Values	Default	Description
--grammar	html, markdown, auto	auto	Grammar to use. auto infers from file extension.
--output	tree, json	tree	Output format. tree prints an indented text representation; json prints the full serialized tree.
--encoding	WHATWG label	utf-8	Input file encoding (e.g. iso-8859-1, windows-1252, utf-16le).

Grammar auto-detection

Extension	Grammar
.html, .htm	html
.md, .markdown	markdown

When reading from stdin (-), --grammar is required.

Exit codes

Code	Meaning
0	Success. A tree was produced, even if it contains LexError nodes.
1	System error (file not found, I/O failure).
2	Argument misuse (missing argument, unknown flag, invalid grammar, invalid encoding).

The CLI always exits 0 when a tree was produced, even when the input has parse errors. Check the JSON output for hasError to detect malformed input.

query

parser query Element index.html
parser query "Element, Text" --grammar html --output json < input.html

Kind names are not HTML tag names

parser query p index.html does NOT find <p> elements. Kind names are AST node type names from the grammar (Element, Text, Doctype, etc.), not HTML tag names. See LexQuery for full pattern documentation.

Options

Flag	Values	Default	Description
--grammar	html, markdown, auto	auto	Grammar to use.
--output	text, json	text	Output format.
--encoding	WHATWG label	utf-8	Input file encoding.

serialize

parser serialize index.html
parser serialize --grammar html < input.html

Parses the input and prints the serialized output to stdout. Both HTML and Markdown serialization are supported. The grammar is detected from the file extension or specified with --grammar.

parser serialize --grammar markdown README.md

Global flags

These flags work with any subcommand:

Flag	Description
--version	Print the version (1.0.0) and exit. Overrides the subcommand.
--quiet	Suppress stderr diagnostic output. Useful in scripts where only the exit code and stdout matter.

Reading from stdin

Use - as the file argument, or pipe input:

echo '<p>Hello</p>' | parser parse --grammar html
cat index.html | parser parse --grammar html --output json

When reading from stdin, --grammar is required. Auto-detection needs a file extension.

Tips

-- separator

Use -- to prevent subsequent arguments from being interpreted as flags. Everything after -- is treated as a positional argument:

parser parse -- some-file.html

--quiet for scripting

Use --quiet to suppress error messages on stderr. The exit code still reflects the result (0 for success, 1 for system errors, 2 for argument errors):

if parser parse --quiet config.html; then
  echo "Parsed successfully"
fi

Encoding selection

For files not in UTF-8, use --encoding with a WHATWG Encoding label:

parser parse --encoding windows-1252 legacy.html
parser parse --output json --encoding iso-8859-1 latin1-file.html

Known limitations in v1.0

• Query selectors are kind names, not CSS selectors. query h1 finds nodes of kind h1 (which does not exist), not <h1> elements.
• No --include-errors flag. The parse --output json format includes hasError per node.
• Multi-file glob patterns and streaming parse for large inputs are not yet supported.