fprintd-verify

verify a fingerprint against enrolled prints

TLDR

Check a scan against everything stored for the current user

$ fprintd-verify

Check against one specific finger

$ fprintd-verify --finger [right-index-finger]

Check another user's prints, which needs root

$ sudo fprintd-verify [username]

Name both the finger and the user

$ sudo fprintd-verify --finger [left-thumb] [username]

Make a non-match fatal, which a script can then act on

$ fprintd-verify --g-fatal-warnings

See the finger names it will accept

$ fprintd-verify --help

SYNOPSIS

fprintd-verify [options] [username]

fprintd-verify tests enrolled fingerprints against the fprintd database. It prompts the user to scan their finger and reports whether the scan matches any enrolled fingerprint. It communicates with the fprintd daemon over D-Bus.This is useful for testing fingerprint enrollment quality and troubleshooting authentication issues. Without specifying a finger, the system attempts to match against any enrolled finger.

PARAMETERS

-f, --finger FINGER

Specify which finger to verify: 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

-h, --help

Display help message

INSTALL

sudo apt install fprintd

sudo dnf install fprintd

sudo pacman -S fprintd

sudo apk add fprintd

sudo zypper install fprintd

nix profile install nixpkgs#fprintd

CAVEATS

Verification success depends on scan quality and may require multiple attempts. Environmental factors like moisture or dirt on the sensor can affect results. This command is for testing purposes; actual login authentication uses the PAM module pam_fprintd. The fprintd daemon must be running for this command to work.