diff -ur v9/ftp_ut.py v10/ftp_ut.py
--- v9/ftp_ut.py	2020-02-16 12:25:20.000000000 +0900
+++ v10/ftp_ut.py	2020-02-16 14:35:41.000000000 +0900
@@ -6,6 +6,7 @@
 import cmd_ut
 import yaml_ut
 import dbg
+import tm_ut
 import arg
 import base
 
@@ -131,13 +132,15 @@
 		do_cmd( cmd )
 		return cmd + '\n'
 
-	def cut_dot(lst):
-		return list( filter( lambda s: s not in ( './', '../' ), lst ) )
+	is_dot = lambda s: s in ( '.', '..', './', '../' )
 
-	def cut_tail(lst, c):
-		return list( map( lambda s: s[:-1] if s and s[-1] == c else s, lst ) )
+	is_dir = lambda lst: any( map( is_dot, lst ) )
 
-	def get_lst(path='', dot=True):
+	cut_dot = lambda lst: list( filter( lambda s: not is_dot( s ), lst ) )
+
+	cut_tail = lambda lst, c: list( map( lambda s: s[:-1] if s and s[-1] == c else s, lst ) )
+
+	def get_lst(path='', dot=True, cut_d=False):
 		r = ls(path) if path else ls()
 		lst = r.strip().split('\n')
 		lst = map( lambda s: s.split(), lst )
@@ -152,13 +155,30 @@
 			if ws[0][0] == 'd':
 				nm += '/'
 			rlst.append( nm )
-		return rlst if dot else cut_dot( rlst )
+		if not dot:
+			rlst = cut_dot( rlst )
+		if cut_d:
+			rlst = cut_tail( rlst, '/' )
+		return rlst
+
+	def is_exist(path):
+		return get_lst( path )
+
+	def get_kind(path, cut_d=False):
+		lst = get_lst( path, cut_d )
+		if not lst:
+			return '' # no entry
+		if not is_dir( lst ):
+			return 'f' # file
+		lst = cut_dot( lst )
+		return to_str( [ 'd' ] + lst ) # directory, and contents
+
 
 	def lstf(path=''):
 		return to_str( get_lst( path ), last=True )
 
 	def rm_rf(path):
-		s = get_kind( path )
+		s = get_kind( path, cut_d=True )
 		if not s:
 			return ''
 
@@ -170,23 +190,84 @@
 			return ''
 
 		r = ''
-		lst = cut_tail( lst[1:], '/' )
-		for name in lst:
+		for name in lst[1:]:
 			r += rm_rf( path + '/' + name )
 		r += rmdir( path )
 		return r
 
-	def is_exist(path):
-		return get_lst( path )
 
-	def get_kind(path):
-		lst = get_lst( path )
-		if not lst:
-			return '' # no entry
-		if './' not in lst and '../' not in lst:
-			return 'f' # file
-		lst = cut_dot( lst )
-		return to_str( [ 'd' ] + lst ) # directory, and contents
+	def cnv_use_fn(s):
+		allow = ( '_', '-', '+', ',' )
+		return ''.join( map( lambda c: c if c.isalnum() or c in allow else '_', s ) )
+
+	call = lambda cmd: cmd_ut.call( cmd ).decode()
+
+	me_str = lambda : cnv_use_fn( call( 'hostname' ) + '_' + call( 'whoami' ) )
+
+	def is_lock_zombi(name, me, now):
+		if name.startswith( me + '.' ):
+			return True
+		ws = name.split( '.' )
+		if not ws:
+			return True
+		s = ws[-1]
+		if len(s) != 4+2+2 + 2+2+2:
+			return True
+		sec = tm_ut.str_to_sec( s )
+		if now - sec > 10 * 60: # 10 min
+			return True
+		return False
+
+	def lock(path):
+		me = me_str()
+
+		now = tm_ut.now_sec()
+		tm = tm_ut.sec_to_str( now )
+
+		lock_d = path + '/_lock'
+
+		kind = get_kind( lock_d, cut_d=False )
+		if kind == 'f':
+			rm_rf( lock_d )
+			kind = ''
+		if kind:
+			lst = cut_tail( kind[1:].split( '\n' ), '/' )
+			for name in lst[:]: # copy
+				if is_lock_zombi( name, me, now ):
+					rm_rf( lock_d + '/' + name )
+					lst.remove( name )
+			if lst:
+				return to_str( ( 'no lock', to_str( lst, pre='  ' ) ), last=True )
+
+		name = me + '.' + tm
+		mkdir( lock_d + '/' + name )
+
+		lst = get_lst( lock_d, dot=False, cut_d=True )
+		lst.remove( name )
+		if lst:
+			return to_str( ( 'no lock', to_str( lst, pre='  ' ) ), last=True )
+
+		return to_str( ( 'get lock', '  ' + name ), last=True )
+
+	def unlock(path):
+		me = me_str()
+
+		lock_d = path + '/_lock'
+
+		kind = get_kind( lock_d, cut_d=False )
+		if kind:
+			if kind == 'f':
+				rm_rf( lock_d )
+			else:
+				lst = cut_tail( kind[1:].split( '\n' ), '/' )
+				for name in lst[:]: # copy
+					if is_lock_zombi( name, me, now ):
+						rm_rf( lock_d + '/' + name )
+						lst.remove( name )
+				if not lst:
+					if get_kind( lock_d ) == 'd':
+						rmdir( lock_d )
+		return ''
 
 	def do_paths(f, paths):
 		r = ''
@@ -242,6 +323,8 @@
 		'  host user passwd ls path ..',
 		'  host user passwd lst path ..',
 		'  host user passwd rm_rf path ..',
+		'  host user passwd lock path ..',
+		'  host user passwd unlock path ..',
 		'',
 		'  site_name in ftp_ut.yaml, can ommit host user passwd'
 	]
@@ -277,7 +360,7 @@
 	ftp = new(host, user, passwd, debug=debug)
 
 	( p0, p1_ ) = ( paths[0], paths[1:] )
-	quiet = p0 in ( 'ls', 'lst' )
+	quiet = p0 in ( 'ls', 'lst', 'lock', 'unlock' )
 
 	ftp.login()
 	if not quiet:
@@ -301,6 +384,10 @@
 		r = ftp.do_paths( ftp.lstf, p1_ ) if p1_ else ftp.lstf()
 	elif p0 == 'rm_rf':
 		r = ftp.do_paths( ftp.rm_rf, p1_ )
+	elif p0 == 'lock':
+		r = ftp.do_paths( ftp.lock, p1_ )
+	elif p0 == 'unlock':
+		r = ftp.do_paths( ftp.unlock, p1_ )
 	else:
 		r = ftp.do_paths( ftp.put, p1_ if p0 == 'put' else paths )
 	dbg.out( r, '' )