function printx509 --description "Helper to pretty-print DER/PEM-encoded X.509 certificates"
    if test (count $argv) -eq 0
        echo "usage: $0 [path(s) to one or more certificates to pretty-print...] "
        return 1
    end
    for cert in $argv
        # TODO: verify filetype of certificate
        openssl x509 -text -noout -in $cert
    end
end