diff -ur v12/ezhtml.py v13/ezhtml.py
--- v12/ezhtml.py	2018-09-20 21:28:51.000000000 +0900
+++ v13/ezhtml.py	2020-02-01 01:15:52.000000000 +0900
@@ -4,6 +4,7 @@
 import yaml
 import six
 import nkf
+import cmd_ut
 
 def cv_amp(s, d='enc'):
 	lst = [ ('&','&amp;'), ('<','&lt;'), ('>','&gt;') ]
@@ -216,7 +217,7 @@
 	b = nkf.get_stdin()
 	opt = nkf.guess(b)
 
-	is_html = lambda : nkf.dec( nkf.do_cmd('file - | grep -i html', b) ).strip()
+	is_html = lambda : nkf.dec( cmd_ut.call_comm('file - | grep -i html', b) ).strip()
 	html = True if 'h' in sys.argv else False if 'y' in sys.argv else is_html()
 
 	u8 = nkf.cvt(b, '-u')