ftp-list: detect availability of MLSD

Some ProFTPd are known not to support MLSD. Detect that by checking for MLST in
FEAT per RFC 3659[1].

 [1]: http://tools.ietf.org/html/rfc3659#page-49

1 files changed, 14 insertions, 1 deletions

diff --git a/ftp-list.py b/ftp-list.py
index 3d7a21b..057b117 100755
--- a/ftp-list.py
+++ b/ftp-list.py
@@ -13,7 +13,8 @@ from ftplib import FTP
 import re
 from datetime import datetime, timezone, date
 
-use_list = False
+# None = auto-detect (FEAT), True = use LIST, False = use MLSD
+use_list = None
 
 user = "anonymous"
 passwd = "anon"
@@ -156,10 +157,22 @@ def format_mlsd(name, facts):
 	line += " " + date_str + " " + name
 	return line
 
+def get_features(ftp):
+	"""Returns supported FTP features (FEAT) in a list"""
+	# cut "211-Features" and "211 End"
+	feats = ftp.sendcmd("FEAT").splitlines()[1:-1]
+	return [ f.strip() for f in feats ]
+
 with FTP() as ftp:
 	ftp.connect(host, port)
 	ftp.login(user, passwd)
 	print(ftp.getwelcome(), file=sys.stderr)
+	feats = get_features(ftp)
+
+	if use_list is None:
+		# use list only if supported
+		use_list = not any(f.startswith("MLST ") for f in feats)
+
 	while dirs:
 		dir = dirs.pop()
 		ftp.cwd(dir)