1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
|
{- various rsync stuff
-
- Copyright 2010-2012 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Utility.Rsync where
import Common
import Data.Char
{- Generates parameters to make rsync use a specified command as its remote
- shell. -}
rsyncShell :: [CommandParam] -> [CommandParam]
rsyncShell command = [Param "-e", Param $ unwords $ map escape (toCommand command)]
where
{- rsync requires some weird, non-shell like quoting in
- here. A doubled single quote inside the single quoted
- string is a single quote. -}
escape s = "'" ++ join "''" (split "'" s) ++ "'"
{- Runs rsync in server mode to send a file. -}
rsyncServerSend :: FilePath -> IO Bool
rsyncServerSend file = rsync $
rsyncServerParams ++ [Param "--sender", File file]
{- Runs rsync in server mode to receive a file. -}
rsyncServerReceive :: FilePath -> IO Bool
rsyncServerReceive file = rsync $ rsyncServerParams ++ [File file]
rsyncServerParams :: [CommandParam]
rsyncServerParams =
[ Param "--server"
-- preserve permissions
, Param "-p"
-- preserve timestamps
, Param "-t"
-- allow resuming of transfers of big files
, Param "--inplace"
-- other options rsync normally uses in server mode
, Params "-e.Lsf ."
]
rsync :: [CommandParam] -> IO Bool
rsync = boolSystem "rsync"
{- Runs rsync, but intercepts its progress output and feeds bytes
- complete values into the callback. The progress output is also output
- to stdout.
-
- The params must enable rsync's --progress mode for this to work.
-}
rsyncProgress :: (Integer -> IO ()) -> [CommandParam] -> IO Bool
rsyncProgress callback params = do
r <- withHandle StdoutHandle createProcessSuccess p (feedprogress 0 [])
{- For an unknown reason, piping rsync's output like this does
- causes it to run a second ssh process, which it neglects to wait
- on. Reap the resulting zombie. -}
reapZombies
return r
where
p = proc "rsync" (toCommand params)
feedprogress prev buf h = do
s <- hGetSomeString h 80
if null s
then return True
else do
putStr s
hFlush stdout
let (mbytes, buf') = parseRsyncProgress (buf++s)
case mbytes of
Nothing -> feedprogress prev buf' h
(Just bytes) -> do
when (bytes /= prev) $
callback bytes
feedprogress bytes buf' h
{- Checks if an rsync url involves the remote shell (ssh or rsh).
- Use of such urls with rsync requires additional shell
- escaping. -}
rsyncUrlIsShell :: String -> Bool
rsyncUrlIsShell s
| "rsync://" `isPrefixOf` s = False
| otherwise = go s
where
-- host::dir is rsync protocol, while host:dir is ssh/rsh
go [] = False
go (c:cs)
| c == '/' = False -- got to directory with no colon
| c == ':' = not $ ":" `isPrefixOf` cs
| otherwise = go cs
{- Checks if a rsync url is really just a local path. -}
rsyncUrlIsPath :: String -> Bool
rsyncUrlIsPath s
| rsyncUrlIsShell s = False
| otherwise = ':' `notElem` s
{- Parses the String looking for rsync progress output, and returns
- Maybe the number of bytes rsynced so far, and any any remainder of the
- string that could be an incomplete progress output. That remainder
- should be prepended to future output, and fed back in. This interface
- allows the output to be read in any desired size chunk, or even one
- character at a time.
-
- Strategy: Look for chunks prefixed with \r (rsync writes a \r before
- the first progress output, and each thereafter). The first number
- after the \r is the number of bytes processed. After the number,
- there must appear some whitespace, or we didn't get the whole number,
- and return the \r and part we did get, for later processing.
-}
parseRsyncProgress :: String -> (Maybe Integer, String)
parseRsyncProgress = go [] . reverse . progresschunks
where
go remainder [] = (Nothing, remainder)
go remainder (x:xs) = case parsebytes (findbytesstart x) of
Nothing -> go (delim:x++remainder) xs
Just b -> (Just b, remainder)
delim = '\r'
{- Find chunks that each start with delim.
- The first chunk doesn't start with it
- (it's empty when delim is at the start of the string). -}
progresschunks = drop 1 . split [delim]
findbytesstart s = dropWhile isSpace s
parsebytes s = case break isSpace s of
([], _) -> Nothing
(_, []) -> Nothing
(b, _) -> readish b
|
