# all-number (e.g. ssh://666.666), which are technically not allowed
# (though some exist on the 'net, apparently)
+# FIXME: this will probably misbehave if raw IP addresses are provided,
+# either IPv4 or IPv6 using the bracket notation.
+
+# FIXME: this doesn't address the use of hashed User IDs.
+
check_service_name() {
local name="$1"
local errs=""