calibre

calibre [options] [path_to_ebook]

path_to_ebook
    Opens the specified ebook file immediately in the Calibre viewer upon launching the GUI.

--with-library=PATH
    Starts Calibre using the library located at the specified PATH instead of the default or last used library.

--shutdown-running
    Sends a signal to a running Calibre instance to shut down gracefully.

--editor
    Launches the Calibre Ebook Editor directly, bypassing the main Calibre GUI.

--viewer
    Launches the Calibre Ebook Viewer directly, useful for quickly opening an ebook without the full GUI.

--help
    Displays a help message detailing all available command-line options and then exits.

--version
    Shows the program's version number and exits.

Calibre is a powerful and open-source ebook management software. It allows users to organize, view, edit, and convert ebooks across various formats. While primarily known for its rich graphical user interface, the calibre command itself launches this GUI, providing access to its comprehensive features like library management, metadata editing, news fetching, and device synchronization.

It serves as the central hub for the Calibre ecosystem, which also includes several dedicated command-line tools for specific tasks such as format conversion (ebook-convert), database management (calibredb), and content serving (calibre-server). It supports a vast array of ebook formats and is cross-platform, making it a versatile tool for ebook enthusiasts.

The calibre command primarily launches the graphical user interface. While it offers some command-line options for initial setup or interaction with a running instance, it is not designed for complex, scriptable ebook manipulations directly. Operations like batch format conversions, deep metadata editing, or hosting an ebook server are handled by dedicated, separate command-line utilities within the Calibre suite (e.g., ebook-convert, calibredb, calibre-server).

The Calibre ecosystem includes a robust set of standalone command-line tools for specific tasks. These include ebook-convert for batch format conversions, calibredb for managing the Calibre database and library, calibre-server for serving your ebook collection over the network, and others like calibre-editor and calibre-viewer for direct access to the editor and viewer components. Users needing automation or scriptable interactions with their ebook library will typically leverage these dedicated tools rather than the main calibre command.

Calibre was initially released in 2006 as libprs500 by Kovid Goyal, created to convert obscure ebook formats for the Sony PRS-500 ebook reader. It quickly evolved beyond a simple converter into a comprehensive ebook management system, gaining its current name calibre in 2008. Its development has been community-driven, with continuous updates adding new features, device support, and format compatibility, establishing it as a leading open-source solution for ebook enthusiasts worldwide.

ebook-convert(1), calibredb(1), calibre-server(1), calibre-editor(1), calibre-viewer(1)