Crab CLI

crab is the official command-line interface for Blue CrabDB, a lightweight, portable key-value database designed for embedded systems, scripting environments, and efficient local storage. With a single executable and a suite of powerful subcommands, crab lets you insert, query, export, import, and manage .crabdb files directly from the terminal. Whether you're building automation scripts, logging sensor data, or managing configurations, crab offers a streamlined, shell-friendly experience with both structured and raw access modes via MyShell and NoShell. It’s small, fast, and designed to fit into your workflow like a natural extension of the UNIX philosophy.

🧰 crab CLI Command Reference

Command	Description
crab --version	Show the current version of the CLI
crab --help	Show help information and command usage
crab get <db> <key>	Fetch the value for a given key
crab put <db> <key> <val>	Insert or update a key-value pair
crab del <db> <key>	Delete a key from the database
crab ls <db> [prefix]	List all keys, optionally filtered by prefix
crab keys <db> <pattern>	Find keys by pattern (wildcard or regex)
crab grep <db> <query>	Search values for matching text
crab watch <db> <pattern>	Watch key changes in real-time like tail -f
crab export <db>	Export database contents (e.g., to JSON/CSV)
crab import <db>	Import entries from a file (JSON/CSV)
crab diff <a.crab> <b.crab>	Show differences between two .crabdb files
crab backup <db>	Backup the database with a timestamped file
crab compact <db>	Optimize the database file by removing obsolete data
crab pipe <db> <mode>	Read/write via stdin/stdout for shell scripting
crab sh <db> [--as <mode>]	Launch MyShell by default, or NoShell with --as noshell

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🧪 Examples:

# Get a value
crab get my.crabdb user:001:name

# Add or update a value
crab put my.crabdb user:001:name "Jellyfish"

# Delete a key
crab del my.crabdb user:001:name

# Interactive shell (default to MyShell)
crab sh my.crabdb

# Interactive shell with NoShell mode
crab sh my.crabdb --as noshell

# Export to JSON
crab export my.crabdb --format json > mydata.json

# Import from CSV
crab import my.crabdb --format csv < newdata.csv

# Watch keys for changes
crab watch my.crabdb "logs:*"

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Prerequisites

Ensure you have the following installed before starting:

• Meson Build System: This project relies on Meson. For installation instructions, visit the official Meson website.

Setting Up Meson Build

1. Install Meson:
   • Follow the installation guide on the Meson website for your operating system.

Setting Up, Compiling, Installing, and Running the Project

1. Clone the Repository:

   git clone https://github.com/fossillogic/crab.git
   cd crab

2. Configure the Build:

   meson setup builddir

3. Compile the Project:

   meson compile -C builddir

4. Install the Project:

   meson install -C builddir

5. Run the Project:

   crab

Contributing

Interested in contributing? Please open pull requests or create issues on the GitHub repository.

Feedback and Support

For issues, questions, or feedback, open an issue on the GitHub repository.

License

This project is licensed under the Mozilla Public License.