This application implements the command-not-found spec at: https://wiki.ubuntu.com/CommandNotFoundMagic

If you want automatic prompts to install the package, set COMMAND_NOT_FOUND_INSTALL_PROMPT in your environment.

To use it in bash, please add the following line to your .bashrc file: . /etc/bash_command_not_found

To use it in zsh, please add the following line to your .zshrc file: . /etc/zsh_command_not_found Note that it overrides the preexec and precmd functions, in case you have defined your own.

Command-not-found will for the following data sources:

1. sqlite3 DB in /usr/share/command-not-found/commands.db, if that is not found it will fallback to (2)
2. legacy /usr/share/command-not-found/programs.d/*.db gdbm style database

The datasource (1) is generated from data found on the archive server in deb822 format. The data is generated via https://code.launchpad.net/~mvo/command-not-found-extractor/+git/command-not-found-extractor and is downloaded via apt update.

The datasource (2) is generated via a static command-not-found-data deb package. It is less rich and dynamic than (1) and should be considered legacy and only be used if no better data source is available.

Simple key/value store with key program_name (e.g. bash) and value a comma separated list of packages that provide the program name. The filename indicates the component and architecuture via: $component-$arch.db.

The database looks like this:

           CREATE TABLE IF NOT EXISTS "commands" 
           (
            [command] TEXT PRIMARY KEY NOT NULL,
            [pkgID] INTEGER NOT NULL,
            FOREIGN KEY ([pkgID]) REFERENCES "pkgs" ([pkgID])
           );
           CREATE TABLE IF NOT EXISTS "packages"
           (
            [pkgID] INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
            [name] TEXT,
            [version] TEXT,
            [priority] INTEGER
           );

There is no need to store the component because we do not display that in c-n-f. Note that the "name" in the "pkgs" table may include an architecture qualifier. This is an optimization for multi-arch systems, by default if there is "bash:amd64" and "bash:i386" on an amd64 multi-arch systems we will not store "bash:i386" in the DB at all and will store "bash:amd64" just as "bash". However for commands that are only available for the foreign arch (e.g. "wine:i386") the full qualified package name is stored in the DB and used in the c-n-f output.

To run the tests type:

$ python -m unittest discover