|
| 1 | +""" |
| 2 | +Path operations common to more than one OS |
| 3 | +Do not use directly. The OS specific modules import the appropriate |
| 4 | +functions from this module themselves. |
| 5 | +""" |
| 6 | +import os |
| 7 | +import stat |
| 8 | + |
| 9 | +__all__ = ['commonprefix', 'exists', 'getatime', 'getctime', 'getmtime', |
| 10 | + 'getsize', 'isdir', 'isfile', 'samefile', 'sameopenfile', |
| 11 | + 'samestat'] |
| 12 | + |
| 13 | + |
| 14 | +# Does a path exist? |
| 15 | +# This is false for dangling symbolic links on systems that support them. |
| 16 | +def exists(path): |
| 17 | + """Test whether a path exists. Returns False for broken symbolic links""" |
| 18 | + try: |
| 19 | + os.stat(path) |
| 20 | + except (OSError, ValueError): |
| 21 | + return False |
| 22 | + return True |
| 23 | + |
| 24 | + |
| 25 | +# This follows symbolic links, so both islink() and isdir() can be true |
| 26 | +# for the same path on systems that support symlinks |
| 27 | +def isfile(path): |
| 28 | + """Test whether a path is a regular file""" |
| 29 | + try: |
| 30 | + st = os.stat(path) |
| 31 | + except (OSError, ValueError): |
| 32 | + return False |
| 33 | + return stat.S_ISREG(st.st_mode) |
| 34 | + |
| 35 | + |
| 36 | +# Is a path a directory? |
| 37 | +# This follows symbolic links, so both islink() and isdir() |
| 38 | +# can be true for the same path on systems that support symlinks |
| 39 | +def isdir(s): |
| 40 | + """Return true if the pathname refers to an existing directory.""" |
| 41 | + try: |
| 42 | + st = os.stat(s) |
| 43 | + except (OSError, ValueError): |
| 44 | + return False |
| 45 | + return stat.S_ISDIR(st.st_mode) |
| 46 | + |
| 47 | + |
| 48 | +def getsize(filename): |
| 49 | + """Return the size of a file, reported by os.stat().""" |
| 50 | + return os.stat(filename).st_size |
| 51 | + |
| 52 | + |
| 53 | +def getmtime(filename): |
| 54 | + """Return the last modification time of a file, reported by os.stat().""" |
| 55 | + return os.stat(filename).st_mtime |
| 56 | + |
| 57 | + |
| 58 | +def getatime(filename): |
| 59 | + """Return the last access time of a file, reported by os.stat().""" |
| 60 | + return os.stat(filename).st_atime |
| 61 | + |
| 62 | + |
| 63 | +def getctime(filename): |
| 64 | + """Return the metadata change time of a file, reported by os.stat().""" |
| 65 | + return os.stat(filename).st_ctime |
| 66 | + |
| 67 | + |
| 68 | +# Return the longest prefix of all list elements. |
| 69 | +def commonprefix(m): |
| 70 | + "Given a list of pathnames, returns the longest common leading component" |
| 71 | + if not m: return '' |
| 72 | + # Some people pass in a list of pathname parts to operate in an OS-agnostic |
| 73 | + # fashion; don't try to translate in that case as that's an abuse of the |
| 74 | + # API and they are already doing what they need to be OS-agnostic and so |
| 75 | + # they most likely won't be using an os.PathLike object in the sublists. |
| 76 | + if not isinstance(m[0], (list, tuple)): |
| 77 | + m = tuple(map(os.fspath, m)) |
| 78 | + s1 = min(m) |
| 79 | + s2 = max(m) |
| 80 | + for i, c in enumerate(s1): |
| 81 | + if c != s2[i]: |
| 82 | + return s1[:i] |
| 83 | + return s1 |
| 84 | + |
| 85 | +# Are two stat buffers (obtained from stat, fstat or lstat) |
| 86 | +# describing the same file? |
| 87 | +def samestat(s1, s2): |
| 88 | + """Test whether two stat buffers reference the same file""" |
| 89 | + return (s1.st_ino == s2.st_ino and |
| 90 | + s1.st_dev == s2.st_dev) |
| 91 | + |
| 92 | + |
| 93 | +# Are two filenames really pointing to the same file? |
| 94 | +def samefile(f1, f2): |
| 95 | + """Test whether two pathnames reference the same actual file""" |
| 96 | + s1 = os.stat(f1) |
| 97 | + s2 = os.stat(f2) |
| 98 | + return samestat(s1, s2) |
| 99 | + |
| 100 | + |
| 101 | +# Are two open files really referencing the same file? |
| 102 | +# (Not necessarily the same file descriptor!) |
| 103 | +def sameopenfile(fp1, fp2): |
| 104 | + """Test whether two open file objects reference the same file""" |
| 105 | + s1 = os.fstat(fp1) |
| 106 | + s2 = os.fstat(fp2) |
| 107 | + return samestat(s1, s2) |
| 108 | + |
| 109 | + |
| 110 | +# Split a path in root and extension. |
| 111 | +# The extension is everything starting at the last dot in the last |
| 112 | +# pathname component; the root is everything before that. |
| 113 | +# It is always true that root + ext == p. |
| 114 | + |
| 115 | +# Generic implementation of splitext, to be parametrized with |
| 116 | +# the separators |
| 117 | +def _splitext(p, sep, altsep, extsep): |
| 118 | + """Split the extension from a pathname. |
| 119 | +
|
| 120 | + Extension is everything from the last dot to the end, ignoring |
| 121 | + leading dots. Returns "(root, ext)"; ext may be empty.""" |
| 122 | + # NOTE: This code must work for text and bytes strings. |
| 123 | + |
| 124 | + sepIndex = p.rfind(sep) |
| 125 | + if altsep: |
| 126 | + altsepIndex = p.rfind(altsep) |
| 127 | + sepIndex = max(sepIndex, altsepIndex) |
| 128 | + |
| 129 | + dotIndex = p.rfind(extsep) |
| 130 | + if dotIndex > sepIndex: |
| 131 | + # skip all leading dots |
| 132 | + filenameIndex = sepIndex + 1 |
| 133 | + while filenameIndex < dotIndex: |
| 134 | + if p[filenameIndex:filenameIndex+1] != extsep: |
| 135 | + return p[:dotIndex], p[dotIndex:] |
| 136 | + filenameIndex += 1 |
| 137 | + |
| 138 | + return p, p[:0] |
| 139 | + |
| 140 | +def _check_arg_types(funcname, *args): |
| 141 | + hasstr = hasbytes = False |
| 142 | + for s in args: |
| 143 | + if isinstance(s, str): |
| 144 | + hasstr = True |
| 145 | + elif isinstance(s, bytes): |
| 146 | + hasbytes = True |
| 147 | + else: |
| 148 | + raise TypeError('%s() argument must be str or bytes, not %r' % |
| 149 | + (funcname, s.__class__.__name__)) from None |
| 150 | + if hasstr and hasbytes: |
| 151 | + raise TypeError("Can't mix strings and bytes in path components") from None |
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