improve missing arg handling

- better error messages
- missing instrument is only allowed with 'list'
- missing argument to be replaced with ? in error message
- sea cli may now be given with 'graph' or 'sea' for service

base.py

@@ -222,7 +222,7 @@ class ServiceManager:
 
         or None, when no wildcard character in ins
         """
-        if ins is None or ins == 'all':
+        if not ins or ins == 'all':
             return list(self.info)
         pat = re.sub(r'(\.|\*)', '.*', ins)
         if pat == ins:
@@ -282,9 +282,9 @@ class ServiceManager:
         return done
 
     def do_stop(self, ins, service=None, *args):
+        if not ins:
+            raise UsageError(f'need instrument or "all" to stop all')
         self.get_info()
-        if ins is None:
-            raise ValueError('use stop all if you really want to stop all')
         ins_list = self.wildcard(ins)
         if ins_list is not None:
             return ins_list
@@ -301,6 +301,8 @@ class ServiceManager:
         return env.get('%s_ROOT' % gr, ''), env
 
     def do_start(self, ins, service=None, cfg='', restart=False, wait=False, logger=None, opts=''):
+        if not ins:
+            raise UsageError(f'need instrument or "all" to start all')
         ins_list = self.wildcard(ins)
         if ins_list is not None:
             return ins_list
@@ -319,10 +321,10 @@ class ServiceManager:
             return
         try:
             service_ports = self.get_ins_info(ins)
-        except ValueError:
-            raise ValueError('do not know %r' % ins)
+        except (KeyError, ValueError):
+            raise UsageError('do not know %r' % ins)
         if ins in self.remote_hosts:
-            raise ValueError('can not start, %s is running on a remote host' % self.group)
+            raise UsageError('can not start, %s is running on a remote host' % self.group)
         services = list(service_ports) if service is None else [service]
         if restart:
             self.stop(ins, service)
@@ -406,8 +408,8 @@ class ServiceManager:
                 os.chdir(wd)
 
     def do_restart(self, ins, service=None, cfg=None, logger=None):
-        if ins is None:
-            raise UsageError("need instance or 'all' or wildcard")
+        if not ins:
+            raise UsageError("need instrument or 'all' or wildcard")
         ins_list = self.wildcard(ins)
         if ins_list is not None:
             if cfg is not None:
@@ -418,7 +420,7 @@ class ServiceManager:
     def do_run(self, ins, service=None, cfg=None, opts=''):
         """for tests: run and wait"""
         if self.wildcard(ins) is not None:
-            raise UsageError('no wildcards allowed with %s run' % self.group)
+            raise UsageError('need instrument and service for "%s run"' % self.group)
         if not service:
             try:
                 service, = self.services