rdfless

A colorful pretty printer for RDF data with ANSI colors.

Description

rdfless is a command-line tool that reads RDF data in various formats (Turtle, TriG, N-Triples, N-Quads) and pretty-prints it with syntax highlighting. It's designed to make RDF data more readable in terminal environments.

Key features:

• Colorized output for different RDF components (subjects, predicates, objects, literals)
• Multiple themes
• Intelligent theme switching based on background color (dark/light)
• Support for reading from files or stdin (piped input)
• Option to expand prefixes or display PREFIX declarations
• Customizable colors through a configuration file
• Pager (minus-based) enabling scrolling up/down in content
• Robust error handling with continue-on-error option
• Flexible filtering by subject, predicate, or object

Usage

Usage: rdfless [OPTIONS] [FILE]...

Arguments:
  [FILE]...  Input files (Turtle, TriG, N-Triples, or N-Quads format)

Options:
      --expand                   Expand prefixes instead of showing PREFIX declarations
      --compact                  Compact mode (opposite of 'expand')
      --format <FORMAT>          Override the input format (auto-detected from file extension by default) Supported formats: turtle, trig, ntriples, nquads [possible values: turtle, trig, ntriples, nquads]
      --pager                    Enable paging for large outputs
      --no-pager                 Disable paging (useful when paging is enabled by default in config)
      --dark-theme               Force dark theme colors
      --light-theme              Force light theme colors
      --no-auto-theme            Disable automatic background detection
      --continue-on-error        Continue parsing even when encountering errors (skip invalid triples)
  -s, --subject <SUBJECT>        Filter by subject (IRI or prefixed name)
  -p, --predicate <PREDICATE>    Filter by predicate (IRI or prefixed name)
  -o, --object <OBJECT>          Filter by object (IRI, prefixed name, or literal value)
  -O, --output <OUTPUT>          Output file (write to file instead of stdout)
      --completion <COMPLETION>  Generate shell completion script for bash, zsh, fish, elvish, or powershell [possible values: bash, elvish, fish, powershell, zsh]
  -h, --help                     Print help
  -V, --version                  Print version

Supported Formats

• Turtle / Turtle-star
• TriG / TriG-star
• N-Triples (NT)
• N-Quads (NQ)

Installation

Quick Install (Linux)

Install the latest version with a single command:

curl -sSL https://raw.githubusercontent.com/larsw/rdfless/main/install.sh | bash

This will download and install the latest Linux binary to ~/.local/bin and optionally add it to your PATH.

Manual Download

Download the latest release for your platform from the GitHub Releases page:

• Linux: rdfless-VERSION-linux-x86_64
• Windows: rdfless-VERSION-windows-x86_64.exe
• macOS: rdfless-VERSION-macos-x86_64
• Debian/Ubuntu: rdfless_VERSION_amd64.deb

Using Cargo

cargo install rdfless

From Source

git clone https://github.com/larsw/rdfless.git
cd rdfless
cargo build --release

The binary will be available at target/release/rdfless.

Using Just

For a complete development workflow with formatting, linting, testing, and building:

# Install Just: https://github.com/casey/just
cargo install just

# Build release version
just build

# Development workflow (format, lint, test, build)
just dev

# Install system-wide (requires sudo)
sudo just install

# Build distribution binaries for all platforms
just dist

# See all available commands
just list

Build Optimizations

Release builds automatically include the following optimizations:

• Debug symbols are stripped from the binary to reduce file size
• If UPX is available on your system path, the binary will be compressed for even smaller file size

These optimizations help create a more compact executable without affecting functionality.

Shell Completion

rdfless supports shell completion for bash, zsh, fish, elvish, and PowerShell. You can generate completion scripts using the --completion flag:

Bash

# Generate completion script
rdfless --completion bash > ~/.local/share/bash-completion/completions/rdfless

# Or for system-wide installation (requires sudo)
sudo rdfless --completion bash > /etc/bash_completion.d/rdfless

Zsh

# Generate completion script (make sure ~/.zfunc is in your fpath)
mkdir -p ~/.zfunc
rdfless --completion zsh > ~/.zfunc/_rdfless

# Add to ~/.zshrc if not already present:
# fpath=(~/.zfunc $fpath)
# autoload -U compinit && compinit

Fish

# Generate completion script
rdfless --completion fish > ~/.config/fish/completions/rdfless.fish

Other Shells

# Generate for elvish
rdfless --completion elvish

# Generate for PowerShell  
rdfless --completion powershell

After installing completions, restart your shell or source the appropriate configuration file.

Usage

# Process a TTL file
rdfless file.ttl

# Process a TriG file
rdfless file.trig

# Process an N-Triples file
rdfless file.nt

# Process an N-Quads file
rdfless file.nq

# Process multiple files
rdfless file1.ttl file2.trig file3.nt file4.nq

# Read from stdin
cat file.ttl | rdfless

# Expand prefixes instead of showing PREFIX declarations
rdfless --expand file.ttl

# Override the input format (auto-detected from file extension by default)
rdfless --format turtle file.rdf
rdfless --format trig file.rdf
rdfless --format ntriples file.rdf
rdfless --format nquads file.rdf

# Continue parsing even if there are errors in the RDF file
rdfless --continue-on-error malformed_file.ttl

# Filter RDF triples by subject
rdfless --filter-subject "ex:john" file.ttl
rdfless --filter-subject "http://example.org/person1" file.ttl

# Filter RDF triples by predicate
rdfless --filter-predicate "foaf:name" file.ttl
rdfless --filter-predicate "http://xmlns.com/foaf/0.1/name" file.ttl

# Filter RDF triples by object (IRI, prefixed name, or literal)
rdfless --filter-object "ex:Person" file.ttl
rdfless --filter-object "John Doe" file.ttl
rdfless --filter-object "http://example.org/Person" file.ttl

# Combine filtering with other options
rdfless --expand --filter-subject "ex:john" --no-pager file.ttl

Configuration

rdfless uses a TOML configuration file to customize colors. The configuration file is located at:

~/.local/rdfless/config.toml

If the file doesn't exist, a default configuration will be created automatically.

Example configuration:

[colors]
subject = "blue"
predicate = "green"
object = "white"
literal = "red"
prefix = "yellow"
base = "yellow"
graph = "yellow"

[output]
expand = false

Available colors:

• Named colors: black, red, green, yellow, blue, magenta, cyan, white
• Bright named colors: bright_black, bright_red, bright_green, bright_yellow, bright_blue, bright_magenta, bright_cyan, bright_white
• CSS color codes: Any valid hex color code in the format #RRGGBB or #RGB (e.g., #336699 or #369)

Example configuration with CSS color codes:

[colors]
subject = "#336699"
predicate = "#00cc00"
object = "#ffffff"
literal = "#ff0000"
prefix = "#ffcc00"
base = "#ffcc00"
graph = "#ffcc00"

[output]
expand = false

Pager Keybindings

When paging is enabled (either through the --pager flag or configuration), rdfless uses the minus pager which provides powerful navigation and search capabilities. For a complete list of available keybindings and shortcuts, see PAGER_KEYBINDINGS.md.

Key highlights:

• Ctrl+C/q: Quit the pager
• Arrow keys/j/k: Scroll up/down line by line
• Page Up/Down: Scroll by full pages
• g/G: Go to top/bottom
• / and ?: Forward and backward search
• n/p: Navigate between search matches

Example

Input:

@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix ex: <https://example.org/> .

ex:Person a rdfs:Class ;
    rdfs:label "Person" .

ex:john a ex:Person ;
    rdfs:label "John Doe" .

Output will be the same content but with syntax highlighting for better readability.

Screenshots

Turtle Format (TTL)

Compact Mode	Expanded Mode

TriG Format (TRIG)

Compact Mode	Expanded Mode

License

This project is licensed under the BSD-3-Clause License - see the LICENSE file for details.

Author

Lars Wilhelmsen lars@lars-backwards.org