Removing Fingerprints from the Database (with examples)

In this article, we will explore the various use cases of the fprintd-delete command. This command allows us to remove fingerprints from the database. We will demonstrate eight different use cases, each with its own code example and explanation.

Use Case 1: Remove all fingerprints for a specific user

To remove all fingerprints for a specific user, we can use the following command:

fprintd-delete username

Motivation

When a user no longer wishes to use fingerprint authentication or if they want to start afresh with new fingerprints, all their existing fingerprints can be removed from the database by executing this command.

Explanation

• username: The username of the user whose fingerprints need to be removed.

Example Output

All fingerprints for user username have been removed successfully.

Use Case 2: Remove a specific fingerprint for a specific user

To remove a specific fingerprint for a specific user, we can use the following command:

fprintd-delete username --finger finger

Motivation

In some scenarios, users may want to remove only a specific fingerprint while keeping others intact. This command allows them to delete a particular fingerprint without affecting the rest.

Explanation

• username: The username of the user whose fingerprint needs to be removed.
• finger: The finger for which the fingerprint needs to be removed. It can be one of the following values: left-thumb, left-index-finger, left-middle-finger, left-ring-finger, left-little-finger, right-thumb, right-index-finger, right-middle-finger, right-ring-finger, or right-little-finger.

Example Output

Fingerprint for user username's finger has been removed successfully.

Use Case 3: Display help

To display the help information for the fprintd-delete command, we can simply run:

fprintd-delete

Motivation

In case we forget the command syntax or need further information about its usage, executing this command will display a detailed help message.

Explanation

No arguments are required for this command.

Example Output

Usage: fprintd-delete [OPTION...] [USER...]

Remove fingerprints from the database.

  -?, --help                    Show this help message
      --version                 Show package version
  -f, --finger=[left-thumb|left-index-finger|left-middle-finger|left-ring-finger|left-little-finger|right-thumb|right-index-finger|right-middle-finger|right-ring-finger|right-little-finger]
                                Remove the fingerprint from the specified finger
                                only
      --quiet                   Do not output any error messages
      --verbose                 Show more verbose error messages
      --force                   Delete the fingerprint without asking for
                                confirmation