| 1 | """
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| 2 | os_path.py - Copy of code from Python's posixpath.py and genericpath.py.
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| 3 | """
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| 4 |
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| 5 | import posix_ as posix
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| 6 |
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| 7 | from mycpp import mylib
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| 8 | from typing import Tuple, List
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| 9 |
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| 10 | extsep = '.'
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| 11 | sep = '/'
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| 12 |
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| 13 |
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| 14 | def join(s1, s2):
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| 15 | # type: (str, str) -> str
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| 16 | """Join pathnames.
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| 17 |
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| 18 | Ignore the previous parts if a part is absolute. Insert a '/' unless the
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| 19 | first part is empty or already ends in '/'.
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| 20 |
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| 21 | Special case of os.path.join() which avoids varargs.
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| 22 | """
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| 23 | if s2.startswith('/') or len(s1) == 0:
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| 24 | # absolute path
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| 25 | return s2
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| 26 |
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| 27 | if s1.endswith('/'):
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| 28 | return s1 + s2
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| 29 |
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| 30 | return '%s/%s' % (s1, s2)
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| 31 |
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| 32 |
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| 33 | if mylib.PYTHON:
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| 34 | def rstrip_slashes(s):
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| 35 | # type: (str) -> str
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| 36 | """Helper for split() and dirname()."""
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| 37 |
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| 38 | # This is an awkward implementation from the Python stdlib, but we rewrite it
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| 39 | # in C++.
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| 40 | n = len(s)
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| 41 | if n and s != '/'*n:
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| 42 | s = s.rstrip('/')
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| 43 | return s
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| 44 |
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| 45 |
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| 46 | # Split a path in head (everything up to the last '/') and tail (the
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| 47 | # rest). If the path ends in '/', tail will be empty. If there is no
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| 48 | # '/' in the path, head will be empty.
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| 49 | # Trailing '/'es are stripped from head unless it is the root.
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| 50 |
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| 51 | def split(p):
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| 52 | # type: (str) -> Tuple[str, str]
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| 53 | """Split a pathname. Returns tuple "(head, tail)" where "tail" is
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| 54 | everything after the final slash. Either part may be empty."""
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| 55 | i = p.rfind('/') + 1
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| 56 | head = p[:i]
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| 57 | tail = p[i:]
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| 58 | head = rstrip_slashes(head)
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| 59 | return head, tail
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| 60 |
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| 61 |
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| 62 | # Split a path in root and extension.
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| 63 | # The extension is everything starting at the last dot in the last
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| 64 | # pathname component; the root is everything before that.
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| 65 | # It is always true that root + ext == p.
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| 66 |
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| 67 | # Generic implementation of splitext, to be parametrized with
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| 68 | # the separators
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| 69 | def _splitext(p, sep, extsep):
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| 70 | # type: (str, str, str) -> Tuple[str, str]
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| 71 | """Split the extension from a pathname.
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| 72 |
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| 73 | Extension is everything from the last dot to the end, ignoring
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| 74 | leading dots. Returns "(root, ext)"; ext may be empty."""
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| 75 |
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| 76 | sepIndex = p.rfind(sep)
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| 77 | dotIndex = p.rfind(extsep)
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| 78 | if dotIndex > sepIndex:
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| 79 | # skip all leading dots
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| 80 | filenameIndex = sepIndex + 1
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| 81 | while filenameIndex < dotIndex:
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| 82 | if p[filenameIndex] != extsep:
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| 83 | return p[:dotIndex], p[dotIndex:]
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| 84 | filenameIndex += 1
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| 85 |
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| 86 | return p, ''
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| 87 |
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| 88 |
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| 89 | # Split a path in root and extension.
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| 90 | # The extension is everything starting at the last dot in the last
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| 91 | # pathname component; the root is everything before that.
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| 92 | # It is always true that root + ext == p.
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| 93 |
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| 94 | def splitext(p):
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| 95 | # type: (str) -> Tuple[str, str]
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| 96 | return _splitext(p, sep, extsep)
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| 97 |
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| 98 |
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| 99 | # Return the tail (basename) part of a path, same as split(path)[1].
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| 100 |
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| 101 | def basename(p):
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| 102 | # type: (str) -> str
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| 103 | """Returns the final component of a pathname"""
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| 104 | i = p.rfind('/') + 1
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| 105 | return p[i:]
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| 106 |
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| 107 |
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| 108 | # Return the head (dirname) part of a path, same as split(path)[0].
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| 109 |
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| 110 | def dirname(p):
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| 111 | # type: (str) -> str
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| 112 | """Returns the directory component of a pathname"""
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| 113 | i = p.rfind('/') + 1
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| 114 | head = p[:i]
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| 115 | head = rstrip_slashes(head)
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| 116 | return head
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| 117 |
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| 118 |
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| 119 | # Normalize a path, e.g. A//B, A/./B and A/foo/../B all become A/B.
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| 120 | # It should be understood that this may change the meaning of the path
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| 121 | # if it contains symbolic links!
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| 122 |
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| 123 | def normpath(path):
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| 124 | # type: (str) -> str
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| 125 | """Normalize path, eliminating double slashes, etc."""
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| 126 |
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| 127 | slash = '/'
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| 128 | dot = '.'
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| 129 | if path == '':
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| 130 | return dot
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| 131 | initial_slashes = path.startswith('/') # type: int
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| 132 | # POSIX allows one or two initial slashes, but treats three or more
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| 133 | # as single slash.
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| 134 | if (initial_slashes and
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| 135 | path.startswith('//') and not path.startswith('///')):
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| 136 | initial_slashes = 2
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| 137 | comps = path.split('/')
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| 138 | new_comps = [] # type: List[str]
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| 139 | for comp in comps:
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| 140 | if len(comp) == 0 or comp == '.': # mycpp rewrite: comp in ('', '.')
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| 141 | continue
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| 142 | if (comp != '..' or (initial_slashes == 0 and len(new_comps) == 0) or
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| 143 | (len(new_comps) and new_comps[-1] == '..')):
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| 144 | new_comps.append(comp)
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| 145 | elif len(new_comps):
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| 146 | new_comps.pop()
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| 147 | comps = new_comps
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| 148 | path = slash.join(comps)
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| 149 | if initial_slashes:
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| 150 | path = slash*initial_slashes + path
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| 151 | return path if len(path) else dot
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| 152 |
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| 153 |
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| 154 | # Return whether a path is absolute.
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| 155 | # Trivial in Posix, harder on the Mac or MS-DOS.
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| 156 |
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| 157 | def isabs(s):
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| 158 | # type: (str) -> bool
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| 159 | """Test whether a path is absolute"""
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| 160 | return s.startswith('/')
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| 161 |
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| 162 |
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| 163 | def abspath(path):
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| 164 | # type: (str) -> str
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| 165 | """Return an absolute path."""
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| 166 | if not isabs(path):
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| 167 | cwd = posix.getcwd()
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| 168 | path = join(cwd, path)
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| 169 | return normpath(path)
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