The snap command is a powerful tool for managing software packages on Linux distributions that support Snapcraft, most notably Ubuntu. It allows users to easily find, install, update, and remove applications in a sandboxed environment, ensuring system stability and security. This guide provides a comprehensive overview of common snap commands and their usage.

Finding and Installing Snaps

Before installing a snap, you can search for available packages and view detailed information about them.

Searching for Packages

To find a specific package in the Snap Store:

snap find <package>

Viewing Package Information

To get detailed information about a package, including its version, description, and available channels:

snap info <package>

Installing Snaps

To install a snap package:

sudo snap install <package>

You can also install from specific channels, such as beta:

sudo snap install <package> --channel=beta

Managing Installed Snaps

Once snaps are installed, you can manage them through various commands.

Listing Installed Snaps

To see all snaps currently installed on your system:

snap list

To view all revisions of installed snaps, including older ones:

snap list --all

Updating Snaps

To manually update all installed snaps:

sudo snap refresh

To update a specific snap:

sudo snap refresh <package>

To update a snap to a specific channel:

sudo snap refresh <package> --channel=beta

Reverting Snaps

If an update causes issues, you can revert to a previous version:

sudo snap revert <package>

To revert to a specific revision number:

snap revert <package> --revision 5

Removing Snaps

To uninstall a snap package:

sudo snap remove <package>

Authentication and Transactions

Snapcraft requires authentication for certain operations and provides tools to track transactions.

Logging In and Out

To log in to your Snapcraft account (you must create an account online first):

sudo snap login

To log out:

snap logout

Transaction Management

To view a summary of recent snap transactions:

snap changes

To view details of a specific transaction (e.g., item 123):

snap change 123

To watch a transaction in real-time:

snap watch 123

To abort an ongoing transaction:

snap abort 123

Advanced Installation and Development

For developers or advanced users, snap offers options for downloading and installing snaps manually.

Downloading Snaps

To download a snap package and its assertions without installing it:

snap download <package>

Installing Local Snaps

To install a locally downloaded snap with its assertions:

snap ack foo.assert
snap install foo.snap

To install a local snap without assertions (use with caution, as integrity is not verified):

snap install --dangerous foo.snap

Development Modes

For development purposes, you can install snaps in devmode or classic mode:

snap install --devmode foo

snap install --classic foo

Snap Interfaces and Permissions

Snaps use interfaces to manage permissions and access system resources.

Viewing Interfaces

To see available snap interfaces:

snap interfaces

Connecting and Disconnecting Interfaces

To connect a snap's plug to a slot (e.g., connecting foo:camera to :camera):

snap connect foo:camera :camera

To disconnect an interface:

snap disconnect foo:camera

Enabling, Disabling, and Setting Properties

You can control the state and configuration of snaps.

Enabling and Disabling Snaps

To disable a snap (stops it from running):

snap disable foo

To enable a disabled snap:

snap enable foo

Setting and Getting Properties

To set a property for a snap (e.g., setting bar to 10 for snap foo):

snap set foo bar=10

To read a snap's property:

snap get foo bar

For more information on Snapcraft and the snap command, refer to the official Snapcraft documentation.