### Build and Install Luaotfload

Source: https://github.com/latex3/luaotfload/blob/main/buildinfo.txt

Commands for installing the package into the texmf tree and updating the file name database.

```bash
l3build install
```

```bash
mktexlsr
```

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

### Luaotfload Configuration File Example

Source: https://context7.com/latex3/luaotfload/llms.txt

An annotated example of the luaotfload.conf file, demonstrating various configuration options for font indexing, feature application, path settings, and runtime behavior. This file is read from standard locations.

```ini
;; luaotfload.conf — full annotated example

[db]
    ;; Font formats to index (otf, ttf, ttc, afm, pfb)
    formats             = otf, ttf, ttc

    ;; Prefer texmf fonts over system fonts when both exist
    location-precedence = texmf, system, local

    ;; Compress the names database with gzip
    compress            = true

    ;; Automatically reload the database on unknown font lookup
    update-live         = true

    ;; Include $PWD in font search (disables on-disk caching)
    scan-local          = false

    ;; Maximum number of font files to process (useful for debugging)
    max-fonts           = 500

[default-features]
    ;; Apply these features globally to all fonts
    global              = mode=node
    ;; Apply extra features for the default (dflt) script
    dflt                = liga, kern

[misc]
    ;; Wrap terminal output at this width (nil = auto-detect)
    termwidth           = 80

    ;; Collect and append statistics to the index file
    statistics          = false

[paths]
    cache-dir           = fonts
    names-dir           = names
    index-file          = luaotfload-names.lua
    lookups-file        = luaotfload-lookup-cache.lua

[run]
    ;; Verbosity: 0 = quiet, 5 = very noisy
    log-level           = 0

    ;; Cache successful name lookups for speed
    resolver            = cached

    ;; Callback stage for per-font colorization
    color-callback      = post_linebreak_filter

    ;; Font definition callback: "patch" (default) or "generic"
    definer             = patch

    ;; Fontloader backend: "default", "reference", "unpackaged", "context"
    fontloader          = default

```

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

### luaotfload-tool: List and Filter Fonts

Source: https://context7.com/latex3/luaotfload/llms.txt

Examples of listing fonts from the database with custom fields and filtering by name patterns.

```bash
# List all indexed fonts sorted by format, showing file and version
luaotfload-tool --list="format" --fields="file->base,version"

# List fonts matching a specific family name
luaotfload-tool --list="names->sanitized->english->family:Noto*" \
                --fields="file->base,style->width"

```

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

### Example Luaotfload Configuration

Source: https://github.com/latex3/luaotfload/blob/main/doc/luaotfload.conf.rst

A sample configuration file demonstrating customizations for font formats, index compression, terminal width, and logging level. Save this to ./luaotfload.conf to test.

```ini
[db]
    formats = afm,ttf
    compress = false

[misc]
    termwidth = 60

[run]
    log-level = 6
```

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

### Luaotfload Configuration File Syntax: Section Declaration

Source: https://github.com/latex3/luaotfload/blob/main/doc/luaotfload.conf.rst

Example of how to declare a new section in the luaotfload.conf file. Sections group related configuration variables.

```ini
[some-section]
    ... section content ...
```

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

### Luaotfload Configuration File Syntax: Variable Assignment

Source: https://github.com/latex3/luaotfload/blob/main/doc/luaotfload.conf.rst

Example of a variable assignment within a section in the luaotfload.conf file. Variables define specific settings for Luaotfload.

```ini
[foo]
    bar = baz
    quux = xyzzy
```

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

### Generate man pages with rst2man.py

Source: https://github.com/latex3/luaotfload/blob/main/todoinfos/scriptcall.txt

Generates man pages from reStructuredText files. Requires docutils to be installed.

```bash
rst2man.py luaotfload.conf.rst luaotfload.conf.5
```

```bash
rst2man.py luaotfload-tool.rst luaotfload.tool.1
```

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

### Import package with mkimport

Source: https://github.com/latex3/luaotfload/blob/main/todoinfos/scriptcall.txt

Imports package files. This command is merged with the call and sets USER and HOSTNAME to get a sensible header.

```bash
texlua scripts/mkimport package
```

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

### Inspect currently loaded fonts

Source: https://context7.com/latex3/luaotfload/llms.txt

Gets a list of all fonts loaded in the current document, along with specified fields like fullname and filename. Useful for font management and debugging.

```lua
-- Retrieve fullname and filename for every loaded font
local loaded = luaotfload.aux.get_loaded_fonts({"fullname", "filename"})
for _, entry in ipairs(loaded) do
  local id      = entry[1]
  local fields  = entry[2]
  texio.write_nl("log", string.format(
    "Font ID %d: %s (%s)", id, tostring(fields[1]), tostring(fields[2])
  ))
end
```

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

### Register and Remove Callback for Font Patching

Source: https://context7.com/latex3/luaotfload/llms.txt

Register a custom patch function to be applied after each font is loaded using `luaotfload.patch_font`. This example demonstrates adding a custom field and logging the font name, as well as forcing a minimum x-height. Callbacks can be removed when no longer needed.

```lua
-- Register a custom patch applied after every font is loaded.
-- This example adds a custom field and logs the font name.
luatexbase.add_to_callback(
  "luaotfload.patch_font",
  function(tfmdata, specification)
    local name = tfmdata.fullname or tfmdata.name or "unknown"
    texio.write_nl("log", "[my-package] Patching font: " .. name)

    -- Example: force a minimum x-height of 400sp for all fonts
    local parameters = tfmdata.parameters
    if parameters and (parameters.x_height or 0) < 400 then
      parameters.x_height = 400
    end
  end,
  "my-package.patch_font_example"
)

-- Remove the callback when no longer needed
luatexbase.remove_from_callback(
  "luaotfload.patch_font",
  "my-package.patch_font_example"
)
```

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

### Bisection of Font Database

Source: https://github.com/latex3/luaotfload/blob/main/doc/luaotfload-tool.rst

Utilize the --bisect directive for debugging the LuaTeX engine, particularly for memory leaks or buggy fonts. Directives include 'run', 'start', and 'stop'.

```bash
--bisect=run
```

```bash
--bisect=start
```

```bash
--bisect=stop
```

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

### luaotfload-tool: Find and Inspect Fonts

Source: https://context7.com/latex3/luaotfload/llms.txt

Demonstrates how to find fonts by name, including fuzzy matching, and how to inspect detailed font information using the luaotfload-tool.

```bash
# Find a font by name; print the resolved file path
luaotfload-tool --find="Linux Libertine O"
# Output: /usr/share/fonts/opentype/linux-libertine/LinLibertine_R.otf

# Find with fuzzy matching (useful for misspellings)
luaotfload-tool --find="Libertine" --fuzzy

# Display detailed font info (loads the font — slow)
luaotfload-tool --find="Linux Libertine O" --inspect

```

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

### luaotfload-tool: Diagnostics and Configuration

Source: https://context7.com/latex3/luaotfload/llms.txt

Commands for running diagnostic checks on the font loading system and dumping the current configuration.

```bash
# Diagnostic checks
luaotfload-tool --diagnose=files,permissions,environment,index

# Dump the current active configuration to stdout
luaotfload-tool --dumpconf

```

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

### Create glyphlist.txt with mkglyphlist

Source: https://github.com/latex3/luaotfload/blob/main/todoinfos/scriptcall.txt

Generates glyphlist.txt. This script may need to be called twice if glyphlist.txt does not exist. Files are created in src/auto.

```bash
texlua scripts/mkglyphlist
```

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

### Luaotfload Tool Configuration Commands

Source: https://context7.com/latex3/luaotfload/llms.txt

Commands using the luaotfload-tool utility to dump the currently active configuration, either the default or a specific configuration file.

```bash
# Dump currently active configuration (including all defaults)
luaotfload-tool --dumpconf > ~/.config/luaotfload/luaotfload.conf

# Load a specific configuration file and then dump it
luaotfload-tool --conf=/path/to/my.conf --dumpconf
```

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

### Import files with mkimport (import)

Source: https://github.com/latex3/luaotfload/blob/main/todoinfos/scriptcall.txt

Imports files from context. This command also imports the merged original file and saves it as fontloader-reference.lua in src/fontloader/runtime. Requires CONTEXTPATH environment variable.

```bash
texlua scripts/mkimport import "" %CONTEXTPATH%
```

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

### Luaotfload Font Request Syntax

Source: https://context7.com/latex3/luaotfload/llms.txt

Illustrates the general syntax for font requests in Luaotfload, covering anonymous, name, and file lookups with various OpenType features and special settings.

```latex
% General form:
%   <lookup>:<name>/<size>:<features>
%   where <lookup> is  name: | file: | path:  (or omitted for anonymous)

% Anonymous lookup — tries tex, path, name in sequence (configurable)
\font\A = {MyFont-Regular} at 12pt

% Name lookup with multiple features
\font\B = {name:TeX Gyre Pagella:+liga;+kern;+smcp;color=FF0000} at 11pt

% File lookup with language/script selection
\font\C = {file:arabtype.ttf:script=arab;language=ARA;mode=harf} at 14pt

% Subfont selection (TTC collections, index 2)
\font\D = {name:Source Han Serif:subfont=2} at 12pt

% Embolden pseudo-feature (fake bold via outline expansion)
\font\E = {name:Linux Libertine O:embolden=2} at 12pt

% Letterspacing
\font\F = {name:Linux Libertine O:letterspace=100} at 12pt

```

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

### Create luaotfload-character.lua with mkcharacters

Source: https://github.com/latex3/luaotfload/blob/main/todoinfos/scriptcall.txt

Generates a new luaotfload-character.lua file. Requires char-def.lua and char-ini.lua. The file is created in src/auto by default. Ensure CONTEXTPATH environment variable is set.

```bash
texlua scripts/mkcharacters %CONTEXTPATH%/tex/context/base/mkiv/
```

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

### luaotfload-tool: Bisect Font Database

Source: https://context7.com/latex3/luaotfload/llms.txt

Instructions for using the bisect command to isolate a problematic font in the database by iteratively narrowing down the search space.

```bash
# Bisect font database to isolate a problematic font
luaotfload-tool --bisect=start
luaotfload-tool --update --bisect=run
luaotfload-tool --bisect=bad   # mark this half as containing the bug
luaotfload-tool --update --bisect=run
luaotfload-tool --bisect=good
# ... repeat until a single font is isolated
luaotfload-tool --bisect=stop

```

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

### Dump Current Luaotfload Configuration

Source: https://github.com/latex3/luaotfload/blob/main/doc/luaotfload.conf.rst

Command to write the current Luaotfload configuration to a file. The output can be used as a new configuration file.

```bash
luaotfload-tool --dumpconf > luaotfload.conf
```

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

### Import files with mkimport (news)

Source: https://github.com/latex3/luaotfload/blob/main/todoinfos/scriptcall.txt

Imports files from context, specifically for new changes. The first argument's purpose is unclear. Requires CONTEXTPATH environment variable.

```bash
texlua scripts/mkimport news "" %CONTEXTPATH%
```

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

### Create CTAN Package

Source: https://github.com/latex3/luaotfload/blob/main/buildinfo.txt

Use l3build ctan to create the package for CTAN. This command handles the packaging process after all other build and documentation steps are completed.

```bash
l3build ctan
```

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

### luaotfload.conf Configuration

Source: https://context7.com/latex3/luaotfload/llms.txt

This section details the configuration options available in the `luaotfload.conf` file, which is an INI-style file used to customize luaotfload's behavior.

```APIDOC
## Configuration File (`luaotfload.conf`)

Luaotfload reads an INI-style configuration file from standard locations (`./luaotfload.conf`, `$XDG_CONFIG_HOME/luaotfload/luaotfload.conf`, `~/.luaotfloadrc`, or via kpathsea).

```ini
;; luaotfload.conf — full annotated example

[db]
    ;; Font formats to index (otf, ttf, ttc, afm, pfb)
    formats             = otf, ttf, ttc

    ;; Prefer texmf fonts over system fonts when both exist
    location-precedence = texmf, system, local

    ;; Compress the names database with gzip
    compress            = true

    ;; Automatically reload the database on unknown font lookup
    update-live         = true

    ;; Include $PWD in font search (disables on-disk caching)
    scan-local          = false

    ;; Maximum number of font files to process (useful for debugging)
    max-fonts           = 500

[default-features]
    ;; Apply these features globally to all fonts
    global              = mode=node
    ;; Apply extra features for the default (dflt) script
    dflt                = liga, kern

[misc]
    ;; Wrap terminal output at this width (nil = auto-detect)
    termwidth           = 80

    ;; Collect and append statistics to the index file
    statistics          = false

[paths]
    cache-dir           = fonts
    names-dir           = names
    index-file          = luaotfload-names.lua
    lookups-file        = luaotfload-lookup-cache.lua

[run]
    ;; Verbosity: 0 = quiet, 5 = very noisy
    log-level           = 0

    ;; Cache successful name lookups for speed
    resolver            = cached

    ;; Callback stage for per-font colorization
    color-callback      = post_linebreak_filter

    ;; Font definition callback: "patch" (default) or "generic"
    definer             = patch

    ;; Fontloader backend: "default", "reference", "unpackaged", "context"
    fontloader          = default
```

```bash
# Dump currently active configuration (including all defaults)
luaotfload-tool --dumpconf > ~/.config/luaotfload/luaotfload.conf

# Load a specific configuration file and then dump it
luaotfload-tool --conf=/path/to/my.conf --dumpconf
```
```

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

### Run Build Checks

Source: https://github.com/latex3/luaotfload/blob/main/buildinfo.txt

Execute the l3build check command to run tests in the default TeX Live and with a development version of luatex.

```bash
l3build check
```

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

### Loading Fonts in LuaLaTeX

Source: https://context7.com/latex3/luaotfload/llms.txt

Demonstrates various methods for loading fonts in LuaLaTeX using Luaotfload's extended syntax, including by name, file, and with OpenType features.

```latex
% --- LuaLaTeX: luaotfload is loaded automatically ---

% Load by font name (from the luaotfload database)
\font\myfont = {name:Linux Libertine O} at 12pt
\myfont Hello, world!

% Load by file name
\font\mono = {file:InconsolataN-Regular.otf} at 10pt

% Load with OpenType features (node mode, default)
\font\smcp = {name:Linux Libertine O:+smcp;+onum} at 11pt

% Load in HarfBuzz mode
\font\harffont = {name:Noto Serif:mode=harf;script=latn;language=ENG} at 12pt

% Load a variable font with axis settings
\font\varfont = {name:Roboto Flex:wght=700;wdth=75} at 12pt

% Path-based load (absolute path or relative)
\font\custom = {[/usr/share/fonts/truetype/MyFont.ttf]} at 12pt

```

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

### luaotfload-tool: Cache Management

Source: https://context7.com/latex3/luaotfload/llms.txt

Commands for managing the Luaotfload cache, including showing statistics, purging Lua cache files, and erasing both Lua and bytecode caches.

```bash
# Cache management
luaotfload-tool --cache=show     # print cache statistics
luaotfload-tool --cache=purge    # delete Lua cache files
luaotfload-tool --cache=erase    # delete Lua and bytecode cache files

# Flush lookup cache only
luaotfload-tool --flush-lookups

```

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

### Upload CTAN Package

Source: https://github.com/latex3/luaotfload/blob/main/buildinfo.txt

Upload the created CTAN package. This is the final step in releasing the package to CTAN.

```bash
l3build upload
```

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

### Add Git Tag and Update Status

Source: https://github.com/latex3/luaotfload/blob/main/buildinfo.txt

Add a git tag for the release and then update the luaotfload-status file again to reflect the new tag. This ensures the status file contains correct hashes.

```bash
git tag -a v2.98 -m 'my version 2.98'
```

```bash
texlua scripts/mkstatus --fontloader=./src/auto/fontloader-2019-07-04.lua
```

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

### Generate Man Pages and Documentation

Source: https://github.com/latex3/luaotfload/blob/main/buildinfo.txt

Commands to generate man pages and TeX documents from reStructuredText files using rst2man.py and rst2xetex.py. These are typically run from the luaotfload/doc directory.

```bash
rst2man.py luaotfload.conf.rst luaotfload.conf.5
```

```bash
rst2xetex.py luaotfload.conf.rst luaotfload-conf.tex
```

```bash
rst2man.py luaotfload-tool.rst luaotfload-tool.1
```

```bash
rst2xetex.py luaotfload-tool.rst luaotfload-tool.tex
```

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

### Show Blacklisted Files

Source: https://github.com/latex3/luaotfload/blob/main/doc/luaotfload-tool.rst

Display a list of blacklisted files. This option does not include directories.

```bash
--show-blacklist
```

```bash
-b
```

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

### List Font Entries by Format

Source: https://github.com/latex3/luaotfload/blob/main/doc/luaotfload-tool.rst

Use the --list and --fields options to display specific font information, sorted by a chosen criterion. Ensure arguments with special characters like '->' are quoted.

```bash
./luaotfload-tool.lua --list="format" --fields="file->base,version"
```

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

### Compile Documentation with LuaLaTeX

Source: https://github.com/latex3/luaotfload/blob/main/buildinfo.txt

Compile various TeX documents using lualatex. This step is part of the documentation generation process.

```bash
lualatex luaotfload-tool.tex
```

```bash
lualatex luaotfload-conf.tex
```

```bash
lualatex filegraph
```

```bash
lualatex
```

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

### Load luaotfload Manually in Plain LuaTeX

Source: https://context7.com/latex3/luaotfload/llms.txt

In Plain LuaTeX, the `luaotfload.sty` package must be loaded explicitly using `\input`. After loading, fonts can be used with the extended syntax, and Lua code can access `luaotfload.version`.

```tex
% Plain LuaTeX: load luaotfload manually
\input luaotfload.sty

% Now fonts can be loaded with the extended syntax
\font\myfont = {name:Linux Libertine O:+liga;+kern} at 12pt
\myfont Hello from Plain LuaTeX!

% Check version from Lua
\directlua{
  texio.write_nl("log", "luaotfload version: " .. luaotfload.version)
}
\bye
```

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

### luaotfload-tool: Update Font Database

Source: https://context7.com/latex3/luaotfload/llms.txt

Commands for updating the Luaotfload font database, including options for incremental updates, full rebuilds, and local directory scanning.

```bash
# Update (index new fonts only)
luaotfload-tool --update

# Force full rebuild
luaotfload-tool --force --update

# Include fonts in the current working directory
luaotfload-tool --update --local

# Limit scanned formats (e.g. only OTF and TTF, skip TTC)
luaotfload-tool --update --formats=-ttc

```

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

### Update luaotfload-status with mkstatus

Source: https://github.com/latex3/luaotfload/blob/main/todoinfos/scriptcall.txt

Updates the luaotfload-status file. The date must be naturally correct. Requires a path to the fontloader status file.

```bash
texlua scripts/mkstatus --fontloader=./src/auto/fontloader-2018-09-19.lua
```

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

### luaotfload.aux.provides_script

Source: https://context7.com/latex3/luaotfload/llms.txt

Determines if a font supports a given OpenType script tag.

```APIDOC
### `luaotfload.aux.provides_script` — Query script support

Returns `true` if the font defines at least one OpenType feature for the given script tag.

```lua
local font_id = font.id("\arabfont")

if luaotfload.aux.provides_script(font_id, "arab") then
  texio.write_nl("log", "Font supports Arabic script.")
end

if luaotfload.aux.provides_script(font_id, "latn") then
  texio.write_nl("log", "Font supports Latin script.")
end
```
```

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

### Tag Build Version

Source: https://github.com/latex3/luaotfload/blob/main/buildinfo.txt

Tag the current build version using l3build tag. This command is used to update version information in build.lua and prepare for CTAN release.

```bash
l3build tag 0
```

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

### Generate TeX files with rst2xetex.py

Source: https://github.com/latex3/luaotfload/blob/main/todoinfos/scriptcall.txt

Converts reStructuredText files to TeX format, suitable for compilation with lualatex.

```bash
rst2xetex.py luaotfload.conf.rst luaotfload.conf.tex
```

```bash
rst2xetex.py luaotfload-tool.rst luaotfload-tool.tex
```

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

### Read the font database index

Source: https://context7.com/latex3/luaotfload/llms.txt

Loads the raw font name index from disk without affecting the live resolver. Useful for inspecting the available font database.

```lua
local index = luaotfload.aux.read_font_index()
local count = 0
for _ in pairs(index) do count = count + 1 end
texio.write_nl("log", "Database entries: " .. tostring(count))
```

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

### Apply per-font color using hex string

Source: https://context7.com/latex3/luaotfload/llms.txt

Adds a tint to text by specifying a hex color string (e.g., RRGGBB or RRGGBBAA) via the `color` pseudo-feature. The color callback can be configured in luaotfload.conf.

```latex
% Red text
\font\redfont = {name:Linux Libertine O:color=FF0000} at 12pt
{\redfont This text is red.}

% Semi-transparent blue (RRGGBBAA)
\font\bluefade = {name:Linux Libertine O:color=0000FF80} at 12pt
{\bluefade This text is translucent blue.}

% Color stage can be changed in luaotfload.conf:
%   [run]
%       color-callback = pre_linebreak_filter  ; or post_linebreak_filter
```

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

### Disable Stripping of Database Information

Source: https://github.com/latex3/luaotfload/blob/main/doc/luaotfload-tool.rst

Use the --no-strip option to prevent the removal of redundant information after building the database. This will significantly increase the index size.

```bash
--no-strip
```

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

### Control Cache Operations

Source: https://github.com/latex3/luaotfload/blob/main/doc/luaotfload-tool.rst

Manage the font and lookup caches using the --cache directive. Options include purging Lua files, erasing both Lua and Luc files, or showing cache statistics.

```bash
--cache=purge
```

```bash
--cache=erase
```

```bash
--cache=show
```

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

### Update Font Index with Luaotfload

Source: https://github.com/latex3/luaotfload/blob/main/doc/luaotfload.conf.rst

Command to update the Luaotfload font index, useful for observing changes after modifying the configuration file. Use --force to overwrite existing index.

```bash
luaotfload-tool --update --force
```

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

### Resolve a font name to a file path

Source: https://context7.com/latex3/luaotfload/llms.txt

Looks up a font name in the database and returns its file path and optional subfont index. Essential for loading fonts by name.

```lua
local path, subfont = luaotfload.aux.resolve_fontname("Linux Libertine O")
if path then
  texio.write_nl("log", "Resolved to: " .. path)
  if subfont then
    texio.write_nl("log", "Subfont index: " .. tostring(subfont))
  end
else
  texio.write_nl("log", "Font not found in database.")
end
```

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

### Query Font Script Support

Source: https://context7.com/latex3/luaotfload/llms.txt

Employs `luaotfload.aux.provides_script` to check if a font includes OpenType features for a specified script tag. This helps in determining if a font is suitable for rendering text in a particular language or writing system, such as Arabic ('arab') or Latin ('latn').

```lua
local font_id = font.id("\arabfont")

if luaotfload.aux.provides_script(font_id, "arab") then
  texio.write_nl("log", "Font supports Arabic script.")
end

if luaotfload.aux.provides_script(font_id, "latn") then
  texio.write_nl("log", "Font supports Latin script.")
end
```

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

### Compile TeX files with lualatex

Source: https://github.com/latex3/luaotfload/blob/main/todoinfos/scriptcall.txt

Compiles TeX files generated from reStructuredText into PDF documents.

```bash
lualatex luaotfload.conf.tex
```

```bash
lualatex luaotfload-tool.tex
```

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

### luaotfload.aux.provides_language

Source: https://context7.com/latex3/luaotfload/llms.txt

Queries if a font supports a given language tag within a specific script. Returns true if supported, false otherwise.

```APIDOC
## luaotfload.aux.provides_language

### Description
Returns `true` if the font supports the given language tag within the given script.

### Parameters
- **font_id** (number) - The ID of the font to query.
- **script** (string) - The script tag (e.g., "latn").
- **language** (string) - The language tag (e.g., "TRK", "dflt").

### Request Example
```lua
local font_id = font.id("\myfont")
if luaotfload.aux.provides_language(font_id, "latn", "TRK") then
  texio.write_nl("log", "Font has Turkish-specific Latin features.")
end
```
```

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

### Read a math parameter from a font

Source: https://context7.com/latex3/luaotfload/llms.txt

Retrieves specific mathematical constants (e.g., rule thickness, scaling factors) from a font's math tables. Useful for precise mathematical typesetting.

```lua
local font_id = font.id("\mathfont")

local frac_rule_thickness = luaotfload.aux.get_math_dimension(font_id, "FractionRuleThickness")
texio.write_nl("log", "FractionRuleThickness = " .. tostring(frac_rule_thickness) .. " sp")

local script_scale = luaotfload.aux.get_math_dimension(font_id, "ScriptPercentScaleDown")
```

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

### Perform a Dry Run

Source: https://github.com/latex3/luaotfload/blob/main/doc/luaotfload-tool.rst

Execute a dry run to debug file system issues. This option scans directories without loading fonts.

```bash
--dry-run
```

```bash
-D
```

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

### luaotfload.aux.name_of_slot

Source: https://context7.com/latex3/luaotfload/llms.txt

Converts a Unicode codepoint to its Adobe Glyph List name.

```APIDOC
### `luaotfload.aux.name_of_slot` — Resolve Unicode codepoint to Adobe Glyph name

Inverse of `slot_of_name`; looks up the AGL name for a given codepoint.

```lua
local name = luaotfload.aux.name_of_slot(0x00E9)  -- U+00E9 é
-- name == "eacute"
texio.write_nl("log", "Glyph name: " .. tostring(name))

local name2 = luaotfload.aux.name_of_slot(0x20AC) -- U+20AC €
-- name2 == "Euro"
```
```

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

### Update Context with Mkimport

Source: https://github.com/latex3/luaotfload/blob/main/buildinfo.txt

Use texlua scripts/mkimport to update the context. This command is used for both news and import operations. Ensure the CONTEXTPATH environment variable is correctly set.

```bash
texlua scripts/mkimport news "" %CONTEXTPATH%
```

```bash
texlua scripts/mkimport news "" $CONTEXTPATH
```

```bash
texlua scripts/mkimport import "" %CONTEXTPATH%
```

```bash
texlua scripts/mkimport import "" $CONTEXTPATH
```

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

### Define fallback fonts for missing glyphs

Source: https://context7.com/latex3/luaotfload/llms.txt

Chains a list of fonts using the `fallback` pseudo-feature to provide missing glyphs. The specified font is tried first, then the fallback font.

```latex
% Define a fallback chain: try main font first, then NotoSans for missing glyphs
\font\mainfb = {name:Linux Libertine O:fallback=NotoSans} at 12pt
{\mainfb Text with CJK characters 你好 will fall back to NotoSans.}
```

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

### Update Luaotfload Status

Source: https://github.com/latex3/luaotfload/blob/main/buildinfo.txt

Use texlua scripts/mkstatus to update the luaotfload status, referencing the default fontloader. Ensure the date is naturally correct.

```bash
texlua scripts/mkstatus --fontloader=./src/auto/fontloader-2020-04-30.lua
```

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

### Generate Luaotfload Characters

Source: https://github.com/latex3/luaotfload/blob/main/buildinfo.txt

Run the mkcharacters script to generate the luaotfload-character.lua file. This script requires char-def.lua and char-ini.lua and creates the output in src/auto by default. Note: This file is no longer used in recent versions.

```bash
texlua scripts/mkcharacters %CONTEXTPATH%/tex/context/base/mkiv/
```

```bash
texlua scripts/mkcharacters $CONTEXTPATH/tex/context/base/mkiv/
```

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

### Query language support in a script

Source: https://context7.com/latex3/luaotfload/llms.txt

Checks if a font supports a specific language tag within a given script. Useful for ensuring correct typographic features are available.

```lua
local font_id = font.id("\myfont")

-- Check for Turkish language support in Latin script
if luaotfload.aux.provides_language(font_id, "latn", "TRK") then
  texio.write_nl("log", "Font has Turkish-specific Latin features.")
end

-- Check for default language
if luaotfload.aux.provides_language(font_id, "latn", "dflt") then
  texio.write_nl("log", "Font has a default language system for Latin.")
end
```

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

### Shaping Modes

Source: https://context7.com/latex3/luaotfload/llms.txt

Configures the OpenType shaping engine used by luaotfload. Available modes are 'node', 'harf', and 'base'.

```APIDOC
## Shaping Modes

### Description
Three shaping modes are available via the `mode` pseudo-feature.

### Modes
- **node**: Default mode. Utilizes ConTeXt's Lua fontloader with full OpenType feature support.
- **harf**: Requires the luahbtex engine. Offers excellent script support.
- **base**: Limited mode. Maps OpenType features to TeX ligatures and kerning; primarily for math fonts.

### Usage Example
```latex
% Default: node mode
\font\nodemode = {name:Noto Serif:mode=node;script=latn;language=ENG} at 12pt

% HarfBuzz mode
\font\harfmode = {name:Noto Serif Arabic:mode=harf;script=arab;language=ARA} at 12pt

% Base mode
\font\basemode = {name:Latin Modern Math:mode=base} at 12pt
```
```

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

### luaotfload.aux.get_loaded_fonts

Source: https://context7.com/latex3/luaotfload/llms.txt

Returns a list of all fonts currently loaded in the document, along with specified fields for each font.

```APIDOC
## luaotfload.aux.get_loaded_fonts

### Description
Returns a list of `{font_id, {field_value, ...}}` pairs for all fonts loaded in the current document.

### Parameters
- **fields** (table of strings) - A list of font fields to retrieve (e.g., {"fullname", "filename"}).

### Request Example
```lua
local loaded = luaotfload.aux.get_loaded_fonts({"fullname", "filename"})
for _, entry in ipairs(loaded) do
  local id      = entry[1]
  local fields  = entry[2]
  texio.write_nl("log", string.format("Font ID %d: %s (%s)", id, tostring(fields[1]), tostring(fields[2])))
end
```
```

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

### luaotfload.aux.provides_feature

Source: https://context7.com/latex3/luaotfload/llms.txt

Checks if a font defines a specific OpenType feature for a given script and language combination. Returns true if the feature is defined, false otherwise.

```APIDOC
## luaotfload.aux.provides_feature

### Description
Returns `true` if the font defines `asked_feature` for the given script and language combination.

### Parameters
- **font_id** (number) - The ID of the font to query.
- **script** (string) - The script tag (e.g., "latn").
- **language** (string) - The language tag (e.g., "dflt").
- **feature** (string) - The feature tag (e.g., "smcp", "onum").

### Request Example
```lua
local font_id = font.id("\myfont")
if luaotfload.aux.provides_feature(font_id, "latn", "dflt", "smcp") then
  texio.write_nl("log", "Font has small capitals (smcp).")
end
```
```

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

### Generate figure with lualatex

Source: https://github.com/latex3/luaotfload/blob/main/todoinfos/scriptcall.txt

Compiles a LaTeX file named 'filegraph' to generate a figure.

```bash
lualatex filegraph
```

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

### Fallback Fonts

Source: https://context7.com/latex3/luaotfload/llms.txt

Chains a list of fonts to provide missing glyphs using the `fallback` feature.

```APIDOC
## Fallback Fonts

### Description
The `fallback` feature chains a list of fonts to fill in missing glyphs.

### Usage Example
```latex
% Define a fallback chain: try main font first, then NotoSans for missing glyphs
\font\mainfb = {name:Linux Libertine O:fallback=NotoSans} at 12pt
{\mainfb Text with CJK characters 你好 will fall back to NotoSans.}
```
```

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

### luaotfload.aux.read_font_index

Source: https://context7.com/latex3/luaotfload/llms.txt

Reads the raw font name index table from disk. This operation does not affect the live font resolver state.

```APIDOC
## luaotfload.aux.read_font_index

### Description
Returns the raw font name index table as read from the database file. Does not affect the live resolver state.

### Request Example
```lua
local index = luaotfload.aux.read_font_index()
local count = 0
for _ in pairs(index) do count = count + 1 end
texio.write_nl("log", "Database entries: " .. tostring(count))
```
```

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

### Flush Font Name Lookup Cache

Source: https://github.com/latex3/luaotfload/blob/main/doc/luaotfload-tool.rst

Clear the font name lookup cache. This is an experimental feature.

```bash
--flush-lookups
```

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

### luaotfload.aux.resolve_fontname

Source: https://context7.com/latex3/luaotfload/llms.txt

Resolves a given font name to its file path and an optional subfont index using the font database.

```APIDOC
## luaotfload.aux.resolve_fontname

### Description
Runs a name-based lookup and returns the resolved file path and optional subfont index.

### Parameters
- **font_name** (string) - The name of the font to resolve.

### Returns
- **path** (string or nil) - The file path to the font, or nil if not found.
- **subfont** (number or nil) - The subfont index, if applicable.

### Request Example
```lua
local path, subfont = luaotfload.aux.resolve_fontname("Linux Libertine O")
if path then
  texio.write_nl("log", "Resolved to: " .. path)
  if subfont then
    texio.write_nl("log", "Subfont index: " .. tostring(subfont))
  end
else
  texio.write_nl("log", "Font not found in database.")
end
```
```

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

### Per-Font Color Feature

Source: https://context7.com/latex3/luaotfload/llms.txt

Applies a tint to a font using a hexadecimal color string via the `color` pseudo-feature.

```APIDOC
## Per-Font Color Feature

### Description
Fonts can be tinted using a hex color string via the `color` pseudo-feature.

### Usage Example
```latex
% Red text
\font\redfont = {name:Linux Libertine O:color=FF0000} at 12pt
{\redfont This text is red.}

% Semi-transparent blue (RRGGBBAA)
\font\bluefade = {name:Linux Libertine O:color=0000FF80} at 12pt
{\bluefade This text is translucent blue.}

% Configuration note:
% Color stage can be changed in luaotfload.conf:
%   [run]
%       color-callback = pre_linebreak_filter  ; or post_linebreak_filter
```
```

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

### Set shaping mode for fonts

Source: https://context7.com/latex3/luaotfload/llms.txt

Configures the text shaping engine for a font using the `mode` pseudo-feature. Supports 'node' (default), 'harf' (for luahbtex), and 'base' (limited, math only).

```latex
% Default: node mode (ConTeXt Lua fontloader, full OpenType feature support)
\font\nodemode = {name:Noto Serif:mode=node;script=latn;language=ENG} at 12pt

% HarfBuzz mode (requires luahbtex engine; excellent script support)
\font\harfmode = {name:Noto Serif Arabic:mode=harf;script=arab;language=ARA} at 12pt

% Base mode (limited — maps OT features to TeX ligatures/kerning; math only)
\font\basemode = {name:Latin Modern Math:mode=base} at 12pt
```

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

### luaotfload.aux.gid_of_name

Source: https://context7.com/latex3/luaotfload/llms.txt

Retrieves the internal Glyph ID (GID) for a glyph specified by its name within a font.

```APIDOC
### `luaotfload.aux.gid_of_name` — Resolve glyph name to GID

Returns the internal Glyph ID (GID) for a named glyph in the given font.

```lua
local font_id = font.id("\myfont")
local gid     = luaotfload.aux.gid_of_name(font_id, "A")
texio.write_nl("log", "GID of 'A': " .. tostring(gid))
```
```

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

### luaotfload.aux.slot_of_name

Source: https://context7.com/latex3/luaotfload/llms.txt

Resolves an Adobe Glyph List name to its corresponding Unicode codepoint (slot) within a font.

```APIDOC
### `luaotfload.aux.slot_of_name` — Resolve Adobe Glyph name to Unicode slot

Returns the Unicode codepoint (slot) for a glyph identified by its Adobe Glyph List name.

```lua
local font_id  = font.id("\myfont")
local slot     = luaotfload.aux.slot_of_name(font_id, "Euro")
-- slot == 0x20AC (8364) for most fonts that contain the Euro glyph

local slot2    = luaotfload.aux.slot_of_name(font_id, "fi") -- fi ligature
if slot2 then
  texio.write_nl("log", string.format("fi ligature at U+%04X", slot2))
end
```
```

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

### luaotfload.aux.provides_axis

Source: https://context7.com/latex3/luaotfload/llms.txt

Determines if a font is a variable font and exposes a requested variation axis. Returns true if the axis is available, false otherwise.

```APIDOC
## luaotfload.aux.provides_axis

### Description
Returns `true` if the font is a variable font that exposes the requested variation axis.

### Parameters
- **font_id** (number) - The ID of the font to query.
- **axis** (string) - The variation axis tag (e.g., "wght", "wdth").

### Request Example
```lua
local font_id = font.id("\varfont")
if luaotfload.aux.provides_axis(font_id, "wght") then
  texio.write_nl("log", "Font has a weight (wght) axis.")
end
```
```

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

### Limit Processed Fonts

Source: https://github.com/latex3/luaotfload/blob/main/doc/luaotfload-tool.rst

Control the maximum number of font files to process, including those already indexed, using the --max-fonts option.

```bash
--max-fonts=N
```

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

### Resolve Unicode Codepoint to Adobe Glyph Name

Source: https://context7.com/latex3/luaotfload/llms.txt

Utilizes `luaotfload.aux.name_of_slot` as the inverse of `slot_of_name`, translating a Unicode codepoint into its Adobe Glyph List name. This is helpful for retrieving the standard name associated with a character, like 'eacute' for 'é' or 'Euro' for '€'.

```lua
local name = luaotfload.aux.name_of_slot(0x00E9)  -- U+00E9 é
-- name == "eacute"
texio.write_nl("log", "Glyph name: " .. tostring(name))

local name2 = luaotfload.aux.name_of_slot(0x20AC) -- U+20AC €
-- name2 == "Euro"
```