| 1 | """Common operations on OS/2 kNIX pathnames.
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| 2 |
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| 3 | Instead of importing this module directly, import os and refer to
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| 4 | this module as os.path. The "os.path" name is an alias for this
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| 5 | module on OS/2 kNIX Posix; on other systems (e.g. Mac, Windows),
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| 6 | os.path provides the same operations in a manner specific to that
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| 7 | platform, and is an alias to another module (e.g. macpath, ntpath).
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| 8 |
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| 9 | This is slightly different from both OS/2 EMX and POSIX, so in order
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| 10 | to avoid messing up those sources, the kNIX code has got a separate
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| 11 | file that drags from both EMX and POSIX.
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| 12 | """
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| 13 |
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| 14 | import os
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| 15 | import stat
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| 16 |
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| 17 | __all__ = ["normcase","isabs","join","splitdrive","split","splitext",
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| 18 | "basename","dirname","commonprefix","getsize","getmtime",
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| 19 | "getatime","getctime","islink","exists","lexists","isdir","isfile",
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| 20 | "ismount","walk","expanduser","expandvars","normpath","abspath",
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| 21 | "samefile","sameopenfile","samestat",
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| 22 | "curdir","pardir","sep","pathsep","defpath","altsep","extsep",
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| 23 | "devnull","realpath","supports_unicode_filenames",
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| 24 | "splitunc"]
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| 25 |
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| 26 | # strings representing various path-related bits and pieces
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| 27 | curdir = '.'
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| 28 | pardir = '..'
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| 29 | extsep = '.'
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| 30 | sep = '/'
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| 31 | altsep = '\\'
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| 32 | pathsep = ';'
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| 33 | defpath = '.;/@unixroot/bin;/@unixroot/usr/bin;/@unixroot/usr/local/bin'
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| 34 | devnull = 'nul'
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| 35 |
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| 36 | # Normalize the case of a pathname. Trivial in Posix, string.lower on Mac.
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| 37 | # On MS-DOS this may also turn slashes into backslashes; however, other
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| 38 | # normalizations (such as optimizing '../' away) are not allowed
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| 39 | # (another function should be defined to do that).
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| 40 |
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| 41 | def normcase(s):
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| 42 | """Normalize case of pathname.
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| 43 |
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| 44 | XXX: This needs to call some kLIBC function to do case corrections, but
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| 45 | I'm not up do that right now.
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| 46 | """
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| 47 | return s.replace('\\', '/')
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| 48 |
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| 49 |
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| 50 | # Return whether a path is absolute.
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| 51 | # Trivial in Posix, harder on the Mac or MS-DOS.
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| 52 | # For DOS it is absolute if it starts with a slash or backslash (current
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| 53 | # volume), or if a pathname after the volume letter and colon / UNC resource
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| 54 | # starts with a slash or backslash.
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| 55 |
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| 56 | def isabs(s):
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| 57 | """Test whether a path is absolute"""
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| 58 | s = splitdrive(s)[1]
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| 59 | return s != '' and s[:1] in '/\\'
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| 60 |
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| 61 |
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| 62 | # Join pathnames.
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| 63 | # Ignore the previous parts if a part is absolute.
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| 64 | # Insert a '/' unless the first part is empty or already ends in '/'.
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| 65 |
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| 66 | def join(a, *p):
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| 67 | """Join two or more pathname components, inserting '/' as needed"""
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| 68 | path = a
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| 69 | for b in p:
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| 70 | if isabs(b):
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| 71 | path = b
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| 72 | elif path == '' or path[-1:] in '/\\:':
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| 73 | path = path + b
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| 74 | else:
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| 75 | path = path + '/' + b
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| 76 | return path
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| 77 |
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| 78 |
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| 79 | # Split a path in a drive specification (a drive letter followed by a
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| 80 | # colon) and the path specification.
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| 81 | # It is always true that drivespec + pathspec == p
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| 82 | def splitdrive(p):
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| 83 | """Split a pathname into drive and path specifiers. Returns a 2-tuple
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| 84 | "(drive,path)"; either part may be empty"""
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| 85 | if p[1:2] == ':':
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| 86 | return p[0:2], p[2:]
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| 87 | return '', p
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| 88 |
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| 89 |
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| 90 | # Parse UNC paths
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| 91 | def splitunc(p):
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| 92 | """Split a pathname into UNC mount point and relative path specifiers.
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| 93 |
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| 94 | Return a 2-tuple (unc, rest); either part may be empty.
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| 95 | If unc is not empty, it has the form '//host/mount' (or similar
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| 96 | using backslashes). unc+rest is always the input path.
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| 97 | Paths containing drive letters never have an UNC part.
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| 98 | """
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| 99 | if p[1:2] == ':':
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| 100 | return '', p # Drive letter present
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| 101 | firstTwo = p[0:2]
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| 102 | if firstTwo == '/' * 2 or firstTwo == '\\' * 2:
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| 103 | # is a UNC path:
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| 104 | # vvvvvvvvvvvvvvvvvvvv equivalent to drive letter
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| 105 | # \\machine\mountpoint\directories...
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| 106 | # directory ^^^^^^^^^^^^^^^
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| 107 | normp = normcase(p)
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| 108 | index = normp.find('/', 2)
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| 109 | if index == -1:
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| 110 | ##raise RuntimeError, 'illegal UNC path: "' + p + '"'
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| 111 | return ("", p)
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| 112 | index = normp.find('/', index + 1)
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| 113 | if index == -1:
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| 114 | index = len(p)
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| 115 | return p[:index], p[index:]
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| 116 | return '', p
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| 117 |
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| 118 |
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| 119 | # Split a path in head (everything up to the last '/') and tail (the
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| 120 | # rest). If the path ends in '/', tail will be empty. If there is no
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| 121 | # '/' in the path, head will be empty.
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| 122 | # Trailing '/'es are stripped from head unless it is the root.
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| 123 |
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| 124 | def split(p):
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| 125 | """Split a pathname. Returns tuple "(head, tail)" where "tail" is
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| 126 | everything after the final slash. Either part may be empty."""
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| 127 |
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| 128 | d, p = splitdrive(p)
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| 129 | # set i to index beyond p's last slash
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| 130 | i = len(p)
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| 131 | while i and p[i-1] not in '/\\':
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| 132 | i = i - 1
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| 133 | head, tail = p[:i], p[i:] # now tail has no slashes
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| 134 | # remove trailing slashes from head, unless it's all slashes
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| 135 | head2 = head
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| 136 | while head2 and head2[-1] in '/\\':
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| 137 | head2 = head2[:-1]
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| 138 | head = head2 or head
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| 139 | return d + head, tail
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| 140 |
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| 141 |
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| 142 | # Split a path in root and extension.
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| 143 | # The extension is everything starting at the last dot in the last
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| 144 | # pathname component; the root is everything before that.
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| 145 | # It is always true that root + ext == p.
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| 146 |
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| 147 | def splitext(p):
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| 148 | """Split the extension from a pathname.
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| 149 |
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| 150 | Extension is everything from the last dot to the end.
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| 151 | Return (root, ext), either part may be empty."""
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| 152 | root, ext = '', ''
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| 153 | for c in p:
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| 154 | if c in ['/','\\']:
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| 155 | root, ext = root + ext + c, ''
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| 156 | elif c == '.':
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| 157 | if ext:
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| 158 | root, ext = root + ext, c
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| 159 | else:
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| 160 | ext = c
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| 161 | elif ext:
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| 162 | ext = ext + c
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| 163 | else:
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| 164 | root = root + c
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| 165 | return root, ext
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| 166 |
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| 167 |
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| 168 | # Return the tail (basename) part of a path.
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| 169 |
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| 170 | def basename(p):
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| 171 | """Returns the final component of a pathname"""
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| 172 | return split(p)[1]
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| 173 |
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| 174 |
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| 175 | # Return the head (dirname) part of a path.
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| 176 |
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| 177 | def dirname(p):
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| 178 | """Returns the directory component of a pathname"""
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| 179 | return split(p)[0]
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| 180 |
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| 181 |
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| 182 | # Return the longest prefix of all list elements.
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| 183 |
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| 184 | def commonprefix(m):
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| 185 | "Given a list of pathnames, returns the longest common leading component"
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| 186 | if not m: return ''
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| 187 | s1 = min(m)
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| 188 | s2 = max(m)
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| 189 | n = min(len(s1), len(s2))
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| 190 | for i in xrange(n):
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| 191 | if s1[i] != s2[i]:
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| 192 | return s1[:i]
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| 193 | return s1[:n]
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| 194 |
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| 195 | # Get size, mtime, atime of files.
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| 196 |
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| 197 | def getsize(filename):
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| 198 | """Return the size of a file, reported by os.stat()."""
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| 199 | return os.stat(filename).st_size
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| 200 |
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| 201 | def getmtime(filename):
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| 202 | """Return the last modification time of a file, reported by os.stat()."""
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| 203 | return os.stat(filename).st_mtime
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| 204 |
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| 205 | def getatime(filename):
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| 206 | """Return the last access time of a file, reported by os.stat()."""
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| 207 | return os.stat(filename).st_atime
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| 208 |
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| 209 | def getctime(filename):
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| 210 | """Return the metadata change time of a file, reported by os.stat()."""
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| 211 | return os.stat(filename).st_ctime
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| 212 |
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| 213 | # Is a path a symbolic link?
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| 214 | # This will always return false on systems where os.lstat doesn't exist.
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| 215 |
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| 216 | def islink(path):
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| 217 | """Test whether a path is a symbolic link"""
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| 218 | try:
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| 219 | st = os.lstat(path)
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| 220 | except (os.error, AttributeError):
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| 221 | return False
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| 222 | return stat.S_ISLNK(st.st_mode)
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| 223 |
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| 224 |
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| 225 | # Does a path exist?
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| 226 | # This is false for dangling symbolic links.
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| 227 |
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| 228 | def exists(path):
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| 229 | """Test whether a path exists. Returns False for broken symbolic links"""
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| 230 | try:
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| 231 | st = os.stat(path)
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| 232 | except os.error:
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| 233 | return False
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| 234 | return True
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| 235 |
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| 236 |
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| 237 | # Being true for dangling symbolic links is also useful.
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| 238 |
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| 239 | def lexists(path):
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| 240 | """Test whether a path exists. Returns True for broken symbolic links"""
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| 241 | try:
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| 242 | st = os.lstat(path)
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| 243 | except os.error:
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| 244 | return False
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| 245 | return True
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| 246 |
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| 247 |
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| 248 | # Is a path a directory?
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| 249 | # This follows symbolic links, so both islink() and isdir() can be true
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| 250 | # for the same path.
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| 251 |
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| 252 | def isdir(path):
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| 253 | """Test whether a path is a directory"""
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| 254 | try:
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| 255 | st = os.stat(path)
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| 256 | except os.error:
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| 257 | return False
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| 258 | return stat.S_ISDIR(st.st_mode)
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| 259 |
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| 260 |
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| 261 | # Is a path a regular file?
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| 262 | # This follows symbolic links, so both islink() and isfile() can be true
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| 263 | # for the same path.
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| 264 |
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| 265 | def isfile(path):
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| 266 | """Test whether a path is a regular file"""
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| 267 | try:
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| 268 | st = os.stat(path)
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| 269 | except os.error:
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| 270 | return False
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| 271 | return stat.S_ISREG(st.st_mode)
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| 272 |
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| 273 |
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| 274 | # Are two filenames really pointing to the same file?
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| 275 |
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| 276 | def samefile(f1, f2):
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| 277 | """Test whether two pathnames reference the same actual file"""
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| 278 | s1 = os.stat(f1)
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| 279 | s2 = os.stat(f2)
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| 280 | return samestat(s1, s2)
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| 281 |
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| 282 |
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| 283 | # Are two open files really referencing the same file?
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| 284 | # (Not necessarily the same file descriptor!)
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| 285 |
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| 286 | def sameopenfile(fp1, fp2):
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| 287 | """Test whether two open file objects reference the same file"""
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| 288 | s1 = os.fstat(fp1)
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| 289 | s2 = os.fstat(fp2)
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| 290 | return samestat(s1, s2)
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| 291 |
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| 292 |
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| 293 | # Are two stat buffers (obtained from stat, fstat or lstat)
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| 294 | # describing the same file?
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| 295 |
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| 296 | def samestat(s1, s2):
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| 297 | """Test whether two stat buffers reference the same file"""
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| 298 | return s1.st_ino == s2.st_ino and \
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| 299 | s1.st_dev == s2.st_dev
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| 300 |
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| 301 |
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| 302 | # Is a path a mount point? Either a root (with or without drive letter)
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| 303 | # or an UNC path with at most a / or \ after the mount point.
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| 304 |
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| 305 | def ismount(path):
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| 306 | """Test whether a path is a mount point (defined as root of drive)
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| 307 | XXX: this isn't correct for if path is a symlink!
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| 308 | """
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| 309 | unc, rest = splitunc(path)
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| 310 | if unc:
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| 311 | return rest in ("", "/", "\\")
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| 312 | p = splitdrive(path)[1]
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| 313 | return len(p) == 1 and p[0] in '/\\'
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| 314 |
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| 315 |
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| 316 | # Directory tree walk.
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| 317 | # For each directory under top (including top itself, but excluding
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| 318 | # '.' and '..'), func(arg, dirname, filenames) is called, where
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| 319 | # dirname is the name of the directory and filenames is the list
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| 320 | # of files (and subdirectories etc.) in the directory.
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| 321 | # The func may modify the filenames list, to implement a filter,
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| 322 | # or to impose a different order of visiting.
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| 323 |
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| 324 | def walk(top, func, arg):
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| 325 | """Directory tree walk with callback function.
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| 326 |
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| 327 | For each directory in the directory tree rooted at top (including top
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| 328 | itself, but excluding '.' and '..'), call func(arg, dirname, fnames).
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| 329 | dirname is the name of the directory, and fnames a list of the names of
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| 330 | the files and subdirectories in dirname (excluding '.' and '..'). func
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| 331 | may modify the fnames list in-place (e.g. via del or slice assignment),
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| 332 | and walk will only recurse into the subdirectories whose names remain in
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| 333 | fnames; this can be used to implement a filter, or to impose a specific
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| 334 | order of visiting. No semantics are defined for, or required of, arg,
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| 335 | beyond that arg is always passed to func. It can be used, e.g., to pass
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| 336 | a filename pattern, or a mutable object designed to accumulate
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| 337 | statistics. Passing None for arg is common."""
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| 338 | try:
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| 339 | names = os.listdir(top)
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| 340 | except os.error:
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| 341 | return
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| 342 | func(arg, top, names)
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| 343 | exceptions = ('.', '..')
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| 344 | for name in names:
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| 345 | if name not in exceptions:
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| 346 | name = join(top, name)
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| 347 | if isdir(name):
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| 348 | walk(name, func, arg)
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| 349 |
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| 350 |
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| 351 | # Expand paths beginning with '~' or '~user'.
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| 352 | # '~' means $HOME; '~user' means that user's home directory.
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| 353 | # If the path doesn't begin with '~', or if the user or $HOME is unknown,
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| 354 | # the path is returned unchanged (leaving error reporting to whatever
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| 355 | # function is called with the expanded path as argument).
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| 356 | # See also module 'glob' for expansion of *, ? and [...] in pathnames.
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| 357 | # (A function should also be defined to do full *sh-style environment
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| 358 | # variable expansion.)
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| 359 |
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| 360 | def expanduser(path):
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| 361 | """Expand ~ and ~user constructs.
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| 362 |
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| 363 | If user or $HOME is unknown, do nothing."""
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| 364 | if path[:1] != '~':
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| 365 | return path
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| 366 | i, n = 1, len(path)
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| 367 | while i < n and path[i] not in '/\\':
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| 368 | i = i + 1
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| 369 | if i == 1:
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| 370 | if 'HOME' in os.environ:
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| 371 | userhome = os.environ['HOME']
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| 372 | elif 'HOMEPATH' in os.environ:
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| 373 | try:
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| 374 | drive = os.environ['HOMEDRIVE']
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| 375 | except KeyError:
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| 376 | drive = ''
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| 377 | userhome = join(drive, os.environ['HOMEPATH'])
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| 378 | else:
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| 379 | import pwd
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| 380 | userhome = pwd.getpwuid(os.getuid()).pw_dir
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| 381 | else:
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| 382 | import pwd
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| 383 | try:
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| 384 | pwent = pwd.getpwnam(path[1:i])
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| 385 | except KeyError:
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| 386 | return path
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| 387 | userhome = pwent.pw_dir
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| 388 |
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| 389 | if userhome.endswith('/') or userhome.endswith('\\'):
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| 390 | i += 1
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| 391 | return userhome + path[i:]
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| 392 |
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| 393 |
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| 394 | # Expand paths containing shell variable substitutions.
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| 395 | # The following rules apply:
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| 396 | # - no expansion within single quotes
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| 397 | # - no escape character, except for '$$' which is translated into '$'
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| 398 | # - ${varname} is accepted.
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| 399 | # - varnames can be made out of letters, digits and the character '_'
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| 400 | # XXX With COMMAND.COM you can use any characters in a variable name,
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| 401 | # XXX except '^|<>='.
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| 402 |
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| 403 | def expandvars(path):
|
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| 404 | """Expand shell variables of form $var and ${var}.
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| 405 |
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| 406 | Unknown variables are left unchanged."""
|
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| 407 | if '$' not in path:
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| 408 | return path
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| 409 | import string
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| 410 | varchars = string.letters + string.digits + '_-'
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| 411 | res = ''
|
|---|
| 412 | index = 0
|
|---|
| 413 | pathlen = len(path)
|
|---|
| 414 | while index < pathlen:
|
|---|
| 415 | c = path[index]
|
|---|
| 416 | if c == '\'': # no expansion within single quotes
|
|---|
| 417 | path = path[index + 1:]
|
|---|
| 418 | pathlen = len(path)
|
|---|
| 419 | try:
|
|---|
| 420 | index = path.index('\'')
|
|---|
| 421 | res = res + '\'' + path[:index + 1]
|
|---|
| 422 | except ValueError:
|
|---|
| 423 | res = res + path
|
|---|
| 424 | index = pathlen - 1
|
|---|
| 425 | elif c == '$': # variable or '$$'
|
|---|
| 426 | if path[index + 1:index + 2] == '$':
|
|---|
| 427 | res = res + c
|
|---|
| 428 | index = index + 1
|
|---|
| 429 | elif path[index + 1:index + 2] == '{':
|
|---|
| 430 | path = path[index+2:]
|
|---|
| 431 | pathlen = len(path)
|
|---|
| 432 | try:
|
|---|
| 433 | index = path.index('}')
|
|---|
| 434 | var = path[:index]
|
|---|
| 435 | if var in os.environ:
|
|---|
| 436 | res = res + os.environ[var]
|
|---|
| 437 | except ValueError:
|
|---|
| 438 | res = res + path
|
|---|
| 439 | index = pathlen - 1
|
|---|
| 440 | else:
|
|---|
| 441 | var = ''
|
|---|
| 442 | index = index + 1
|
|---|
| 443 | c = path[index:index + 1]
|
|---|
| 444 | while c != '' and c in varchars:
|
|---|
| 445 | var = var + c
|
|---|
| 446 | index = index + 1
|
|---|
| 447 | c = path[index:index + 1]
|
|---|
| 448 | if var in os.environ:
|
|---|
| 449 | res = res + os.environ[var]
|
|---|
| 450 | if c != '':
|
|---|
| 451 | res = res + c
|
|---|
| 452 | else:
|
|---|
| 453 | res = res + c
|
|---|
| 454 | index = index + 1
|
|---|
| 455 | return res
|
|---|
| 456 |
|
|---|
| 457 |
|
|---|
| 458 | # Normalize a path, e.g. A//B, A/./B and A/foo/../B all become A/B.
|
|---|
| 459 |
|
|---|
| 460 | def normpath(path):
|
|---|
| 461 | """Normalize path, eliminating double slashes, etc."""
|
|---|
| 462 | path = path.replace('\\', '/')
|
|---|
| 463 | prefix, path = splitdrive(path)
|
|---|
| 464 | while path[:1] == '/':
|
|---|
| 465 | prefix = prefix + '/'
|
|---|
| 466 | path = path[1:]
|
|---|
| 467 | comps = path.split('/')
|
|---|
| 468 | i = 0
|
|---|
| 469 | while i < len(comps):
|
|---|
| 470 | if comps[i] == '.':
|
|---|
| 471 | del comps[i]
|
|---|
| 472 | elif comps[i] == '..' and i > 0 and comps[i-1] not in ('', '..'):
|
|---|
| 473 | del comps[i-1:i+1]
|
|---|
| 474 | i = i - 1
|
|---|
| 475 | elif comps[i] == '' and i > 0 and comps[i-1] != '':
|
|---|
| 476 | del comps[i]
|
|---|
| 477 | else:
|
|---|
| 478 | i = i + 1
|
|---|
| 479 | # If the path is now empty, substitute '.'
|
|---|
| 480 | if not prefix and not comps:
|
|---|
| 481 | comps.append('.')
|
|---|
| 482 | return prefix + '/'.join(comps)
|
|---|
| 483 |
|
|---|
| 484 |
|
|---|
| 485 | # Return an absolute path.
|
|---|
| 486 | def abspath(path):
|
|---|
| 487 | """Return the absolute version of a path"""
|
|---|
| 488 | if not isabs(path):
|
|---|
| 489 | path = join(os.getcwd(), path)
|
|---|
| 490 | return normpath(path)
|
|---|
| 491 |
|
|---|
| 492 |
|
|---|
| 493 | # Return a canonical path (i.e. the absolute location of a file on the
|
|---|
| 494 | # filesystem).
|
|---|
| 495 |
|
|---|
| 496 | def realpath(filename):
|
|---|
| 497 | """Return the canonical path of the specified filename, eliminating any
|
|---|
| 498 | symbolic links encountered in the path."""
|
|---|
| 499 | filename.replace('\\', '/') # simpler this way..
|
|---|
| 500 | if isabs(filename):
|
|---|
| 501 | bits = ['/'] + filename.split('/')[1:]
|
|---|
| 502 | else:
|
|---|
| 503 | bits = [''] + filename.split('/')
|
|---|
| 504 |
|
|---|
| 505 | for i in range(2, len(bits)+1):
|
|---|
| 506 | component = join(*bits[0:i])
|
|---|
| 507 | # Resolve symbolic links.
|
|---|
| 508 | if islink(component):
|
|---|
| 509 | resolved = _resolve_link(component)
|
|---|
| 510 | if resolved is None:
|
|---|
| 511 | # Infinite loop -- return original component + rest of the path
|
|---|
| 512 | return abspath(join(*([component] + bits[i:])))
|
|---|
| 513 | else:
|
|---|
| 514 | newpath = join(*([resolved] + bits[i:]))
|
|---|
| 515 | return realpath(newpath)
|
|---|
| 516 |
|
|---|
| 517 | return abspath(filename)
|
|---|
| 518 |
|
|---|
| 519 |
|
|---|
| 520 | def _resolve_link(path):
|
|---|
| 521 | """Internal helper function. Takes a path and follows symlinks
|
|---|
| 522 | until we either arrive at something that isn't a symlink, or
|
|---|
| 523 | encounter a path we've seen before (meaning that there's a loop).
|
|---|
| 524 | """
|
|---|
| 525 | paths_seen = []
|
|---|
| 526 | while islink(path):
|
|---|
| 527 | if path in paths_seen:
|
|---|
| 528 | # Already seen this path, so we must have a symlink loop
|
|---|
| 529 | return None
|
|---|
| 530 | paths_seen.append(path)
|
|---|
| 531 | # Resolve where the link points to
|
|---|
| 532 | resolved = os.readlink(path)
|
|---|
| 533 | if not isabs(resolved):
|
|---|
| 534 | dir = dirname(path)
|
|---|
| 535 | path = normpath(join(dir, resolved))
|
|---|
| 536 | else:
|
|---|
| 537 | path = normpath(resolved)
|
|---|
| 538 | return path
|
|---|
| 539 |
|
|---|
| 540 | supports_unicode_filenames = False
|
|---|
| 541 |
|
|---|
