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
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
|
{- path manipulation
-
- Copyright 2010-2011 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Utility.Path where
import Data.String.Utils
import System.Path
import System.FilePath
import System.Directory
import Data.List
import Data.Maybe
import Control.Applicative
import System.Posix.User
import Utility.Monad
{- Returns the parent directory of a path. Parent of / is "" -}
parentDir :: FilePath -> FilePath
parentDir dir
| not $ null dirs = slash ++ join s (init dirs)
| otherwise = ""
where
dirs = filter (not . null) $ split s dir
slash = if isAbsolute dir then s else ""
s = [pathSeparator]
prop_parentDir_basics :: FilePath -> Bool
prop_parentDir_basics dir
| null dir = True
| dir == "/" = parentDir dir == ""
| otherwise = p /= dir
where
p = parentDir dir
{- Checks if the first FilePath is, or could be said to contain the second.
- For example, "foo/" contains "foo/bar". Also, "foo", "./foo", "foo/" etc
- are all equivilant.
-}
dirContains :: FilePath -> FilePath -> Bool
dirContains a b = a == b || a' == b' || (a'++"/") `isPrefixOf` b'
where
norm p = fromMaybe "" $ absNormPath p "."
a' = norm a
b' = norm b
{- Converts a filename into a normalized, absolute path.
-
- Unlike Directory.canonicalizePath, this does not require the path
- already exists. -}
absPath :: FilePath -> IO FilePath
absPath file = do
cwd <- getCurrentDirectory
return $ absPathFrom cwd file
{- Converts a filename into a normalized, absolute path
- from the specified cwd. -}
absPathFrom :: FilePath -> FilePath -> FilePath
absPathFrom cwd file = fromMaybe bad $ absNormPath cwd file
where
bad = error $ "unable to normalize " ++ file
{- Constructs a relative path from the CWD to a file.
-
- For example, assuming CWD is /tmp/foo/bar:
- relPathCwdToFile "/tmp/foo" == ".."
- relPathCwdToFile "/tmp/foo/bar" == ""
-}
relPathCwdToFile :: FilePath -> IO FilePath
relPathCwdToFile f = relPathDirToFile <$> getCurrentDirectory <*> absPath f
{- Constructs a relative path from a directory to a file.
-
- Both must be absolute, and normalized (eg with absNormpath).
-}
relPathDirToFile :: FilePath -> FilePath -> FilePath
relPathDirToFile from to = join s $ dotdots ++ uncommon
where
s = [pathSeparator]
pfrom = split s from
pto = split s to
common = map fst $ takeWhile same $ zip pfrom pto
same (c,d) = c == d
uncommon = drop numcommon pto
dotdots = replicate (length pfrom - numcommon) ".."
numcommon = length common
prop_relPathDirToFile_basics :: FilePath -> FilePath -> Bool
prop_relPathDirToFile_basics from to
| from == to = null r
| otherwise = not (null r)
where
r = relPathDirToFile from to
prop_relPathDirToFile_regressionTest :: Bool
prop_relPathDirToFile_regressionTest = same_dir_shortcurcuits_at_difference
where
{- Two paths have the same directory component at the same
- location, but it's not really the same directory.
- Code used to get this wrong. -}
same_dir_shortcurcuits_at_difference =
relPathDirToFile "/tmp/r/lll/xxx/yyy/18" "/tmp/r/.git/annex/objects/18/gk/SHA256-foo/SHA256-foo" == "../../../../.git/annex/objects/18/gk/SHA256-foo/SHA256-foo"
{- Given an original list of files, and an expanded list derived from it,
- ensures that the original list's ordering is preserved.
-
- The input list may contain a directory, like "dir" or "dir/". Any
- items in the expanded list that are contained in that directory will
- appear at the same position as it did in the input list.
-}
preserveOrder :: [FilePath] -> [FilePath] -> [FilePath]
preserveOrder [] new = new
preserveOrder [_] new = new -- optimisation
preserveOrder (l:ls) new = found ++ preserveOrder ls rest
where
(found, rest)=partition (l `dirContains`) new
{- Runs an action that takes a list of FilePaths, and ensures that
- its return list preserves order.
-
- This assumes that it's cheaper to call preserveOrder on the result,
- than it would be to run the action separately with each param. In the case
- of git file list commands, that assumption tends to hold.
-}
runPreserveOrder :: ([FilePath] -> IO [FilePath]) -> [FilePath] -> IO [FilePath]
runPreserveOrder a files = preserveOrder files <$> a files
{- Current user's home directory. -}
myHomeDir :: IO FilePath
myHomeDir = homeDirectory <$> (getUserEntryForID =<< getEffectiveUserID)
{- Checks if a command is available in PATH. -}
inPath :: String -> IO Bool
inPath command = getSearchPath >>= anyM indir
where
indir d = doesFileExist $ d </> command
{- Checks if a filename is a unix dotfile. All files inside dotdirs
- count as dotfiles. -}
dotfile :: FilePath -> Bool
dotfile file
| f == "." = False
| f == ".." = False
| f == "" = False
| otherwise = "." `isPrefixOf` f || dotfile (takeDirectory file)
where
f = takeFileName file
|
