calibre

calibre [--help] [--version] [--debug [LEVEL]] [--ignore-plugins] [--plugin-paths PATHS] [--with-library LIBRARY_PATH]

--help
    Show this help message and exit

--version
    Show program's version number and exit

--debug [LEVEL]
    Enable debug mode (NO_DEBUG, DEBUG, PROFILE)

--ignore-plugins
    Ignore all installed plugins

--plugin-paths PATHS
    Comma-separated paths/URLs for plugins

--with-library LIBRARY_PATH
    Path to specific library folder (default: ~/calibre)

--detach
    Detach from terminal after startup

Calibre is a free, open-source e-book management application that allows users to organize, convert, edit, and read digital books. Developed by Kovid Goyal, it supports dozens of input/output formats like EPUB, MOBI, AZW3, PDF, and more.

On Linux, the calibre command launches the intuitive graphical user interface (GUI), where users can add books, fetch metadata from online sources (e.g., Google Books, Amazon), edit covers and metadata, convert formats for specific devices (Kindle, Kobo), and manage libraries with tags, series, ratings, and custom columns. It includes a built-in viewer, content server for wireless transfer, and device drivers for direct e-reader syncing.

Calibre's strength lies in its extensibility via plugins for news downloads, format tweaks, and more. Libraries are stored as folders with a SQLite database (metadata.db), enabling easy backups and multi-library support. While GUI-centric, it integrates seamlessly with CLI tools for scripting. Ideal for avid readers building large collections, it handles tens of thousands of books efficiently but requires ample disk space.

Requires substantial RAM/disk for large libraries and conversions. GUI launch may fail without display server (use CLI tools instead). Plugins can cause instability if incompatible.

Each library is a folder with metadata.db, book files, and subdirs for covers/cache. Use calibredb for CLI management.

On Debian/Ubuntu: sudo apt install calibre. Or download standalone from calibre-ebook.com; auto-updates via GUI.

Launch GUI with custom library: calibre --with-library /path/to/library. Pair with ebook-convert for batch jobs.

First released in October 2006 by Kovid Goyal to convert books for his Sony PRS-500 Reader. Evolved from simple converter to full suite by 2010 with GUI, library management, and plugins. Actively maintained with frequent releases; version 7.x in 2024 supports modern formats/devices.

ebook-convert(1), calibredb(1), calibre-debug(1), ebook-viewer(1), ebook-edit(1), calibre-server(1)