#!/usr/bin/bash
keys=()

fingerprints=$(gpg --list-public-keys | grep 'Key fingerprint' | sed 's/\s\{6\}Key fingerprint = //')
while read -r fp; do
	keys+=("$fp")
done <<<"$fingerprints"

for key in "${keys[@]}"; do
	gpg --list-sigs "$key" | grep 'sig' | sed 's/^sig .\s\{8\}//' | cut -d' ' -f1 | grep "$1" 2>&1 >/dev/null
	if [[ $? == 0 ]]; then
		printf "%s %s\n" "You signed:" "$key"
	fi
done