Unlock smartcard PIN without decrypting a file

[jman]

> To do the verification without any operation you can use "gpg
> --card-edit" and then enter "verify".

> If you want to see the commands send to the scd run
> gpg --debug ipc --card-edit

Thank you so much for the detailed anwser! Based on your suggestion I
could debug that the "verify" command sends:

gpg/card> verify
gpg: DBG: chan_4 -> SCD CHECKPIN AAABBBCCCDDD
gpg: DBG: chan_4 <- INQUIRE PINENTRY_LAUNCHED 401855 tty 1.1.0 /dev/pts/0 
xterm-kitty -
gpg: DBG: chan_4 -> END

therefore the onliner I was looking for could look like this:

gpg-connect-agent 'SCD CHECKPIN AAABBBCCCDDD' /bye

("AAABBBCCCDDD" being the serial number of the smartcard)

regards,