1 | # Module 'os2emxpath' -- common operations on OS/2 pathnames
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2 | """Common pathname manipulations, OS/2 EMX version.
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3 |
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4 | Instead of importing this module directly, import os and refer to this
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5 | module as os.path.
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6 | """
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7 |
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8 | import os
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9 | import stat
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10 | from genericpath import *
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11 | from ntpath import (expanduser, expandvars, isabs, islink, splitdrive,
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12 | splitext, split, walk)
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13 |
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14 | __all__ = ["normcase","isabs","join","splitdrive","split","splitext",
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15 | "basename","dirname","commonprefix","getsize","getmtime",
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16 | "getatime","getctime", "islink","exists","lexists","isdir","isfile",
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17 | "ismount","walk","expanduser","expandvars","normpath","abspath",
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18 | "samefile","sameopenfile","samestat",
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19 | "splitunc","curdir","pardir","sep","pathsep","defpath","altsep",
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20 | "extsep","devnull","realpath","supports_unicode_filenames"]
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21 |
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22 | # strings representing various path-related bits and pieces
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23 | curdir = '.'
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24 | pardir = '..'
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25 | extsep = '.'
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26 | sep = '/'
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27 | altsep = '\\'
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28 | pathsep = ';'
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29 | defpath = '.;C:\\bin'
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30 | devnull = 'nul'
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31 |
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32 | # Normalize the case of a pathname and map slashes to backslashes.
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33 | # Other normalizations (such as optimizing '../' away) are not done
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34 | # (this is done by normpath).
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35 |
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36 | def normcase(s):
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37 | """Normalize case of pathname.
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38 |
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39 | Makes all characters lowercase and all altseps into seps."""
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40 | return s.replace('\\', '/').lower()
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41 |
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42 |
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43 | # Join two (or more) paths.
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44 |
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45 | def join(a, *p):
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46 | """Join two or more pathname components, inserting sep as needed"""
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47 | path = a
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48 | for b in p:
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49 | if isabs(b):
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50 | path = b
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51 | elif path == '' or path[-1:] in '/\\:':
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52 | path = path + b
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53 | else:
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54 | path = path + '/' + b
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55 | return path
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56 |
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57 |
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58 | # Parse UNC paths
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59 | def splitunc(p):
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60 | """Split a pathname into UNC mount point and relative path specifiers.
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61 |
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62 | Return a 2-tuple (unc, rest); either part may be empty.
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63 | If unc is not empty, it has the form '//host/mount' (or similar
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64 | using backslashes). unc+rest is always the input path.
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65 | Paths containing drive letters never have an UNC part.
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66 | """
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67 | if p[1:2] == ':':
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68 | return '', p # Drive letter present
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69 | firstTwo = p[0:2]
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70 | if firstTwo == '/' * 2 or firstTwo == '\\' * 2:
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71 | # is a UNC path:
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72 | # vvvvvvvvvvvvvvvvvvvv equivalent to drive letter
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73 | # \\machine\mountpoint\directories...
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74 | # directory ^^^^^^^^^^^^^^^
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75 | normp = normcase(p)
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76 | index = normp.find('/', 2)
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77 | if index == -1:
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78 | ##raise RuntimeError, 'illegal UNC path: "' + p + '"'
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79 | return ("", p)
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80 | index = normp.find('/', index + 1)
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81 | if index == -1:
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82 | index = len(p)
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83 | return p[:index], p[index:]
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84 | return '', p
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85 |
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86 |
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87 | # Return the tail (basename) part of a path.
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88 |
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89 | def basename(p):
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90 | """Returns the final component of a pathname"""
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91 | return split(p)[1]
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92 |
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93 |
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94 | # Return the head (dirname) part of a path.
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95 |
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96 | def dirname(p):
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97 | """Returns the directory component of a pathname"""
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98 | return split(p)[0]
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99 |
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100 |
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101 | # Is a path a directory?
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102 |
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103 | # Is a path a mount point? Either a root (with or without drive letter)
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104 | # or an UNC path with at most a / or \ after the mount point.
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105 |
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106 | def ismount(path):
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107 | """Test whether a path is a mount point (defined as root of drive)"""
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108 | unc, rest = splitunc(path)
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109 | if unc:
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110 | return rest in ("", "/", "\\")
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111 | p = splitdrive(path)[1]
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112 | return len(p) == 1 and p[0] in '/\\'
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113 |
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114 |
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115 | # Normalize a path, e.g. A//B, A/./B and A/foo/../B all become A/B.
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116 |
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117 | def normpath(path):
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118 | """Normalize path, eliminating double slashes, etc."""
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119 | path = path.replace('\\', '/')
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120 | prefix, path = splitdrive(path)
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121 | while path[:1] == '/':
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122 | prefix = prefix + '/'
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123 | path = path[1:]
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124 | comps = path.split('/')
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125 | i = 0
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126 | while i < len(comps):
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127 | if comps[i] == '.':
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128 | del comps[i]
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129 | elif comps[i] == '..' and i > 0 and comps[i-1] not in ('', '..'):
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130 | del comps[i-1:i+1]
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131 | i = i - 1
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132 | elif comps[i] == '' and i > 0 and comps[i-1] != '':
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133 | del comps[i]
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134 | else:
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135 | i = i + 1
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136 | # If the path is now empty, substitute '.'
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137 | if not prefix and not comps:
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138 | comps.append('.')
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139 | return prefix + '/'.join(comps)
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140 |
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141 |
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142 | # Return an absolute path.
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143 | def abspath(path):
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144 | """Return the absolute version of a path"""
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145 | if not isabs(path):
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146 | path = join(os.getcwd(), path)
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147 | return normpath(path)
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148 |
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149 |
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150 | # Return a canonical path (i.e. the absolute location of a file on the
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151 | # filesystem).
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152 |
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153 | def realpath(filename):
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154 | """Return the canonical path of the specified filename, eliminating any
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155 | symbolic links encountered in the path."""
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156 | if isabs(filename):
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157 | bits = ['/'] + filename.split('/')[1:]
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158 | else:
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159 | bits = [''] + filename.split('/')
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160 |
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161 | for i in range(2, len(bits)+1):
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162 | component = join(*bits[0:i])
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163 | # Resolve symbolic links.
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164 | if islink(component):
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165 | resolved = _resolve_link(component)
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166 | if resolved is None:
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167 | # Infinite loop -- return original component + rest of the path
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168 | return abspath(join(*([component] + bits[i:])))
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169 | else:
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170 | newpath = join(*([resolved] + bits[i:]))
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171 | return realpath(newpath)
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172 |
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173 | return abspath(filename)
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174 |
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175 |
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176 | def _resolve_link(path):
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177 | """Internal helper function. Takes a path and follows symlinks
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178 | until we either arrive at something that isn't a symlink, or
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179 | encounter a path we've seen before (meaning that there's a loop).
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180 | """
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181 | paths_seen = []
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182 | while islink(path):
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183 | if path in paths_seen:
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184 | # Already seen this path, so we must have a symlink loop
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185 | return None
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186 | paths_seen.append(path)
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187 | # Resolve where the link points to
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188 | resolved = os.readlink(path)
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189 | if not isabs(resolved):
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190 | dir = dirname(path)
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191 | path = normpath(join(dir, resolved))
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192 | else:
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193 | path = normpath(resolved)
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194 | return path
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195 |
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196 |
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197 | # Is a path a symbolic link?
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198 | # This will always return false on systems where os.lstat doesn't exist.
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199 |
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200 | def islink(path):
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201 | """Test whether a path is a symbolic link"""
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202 | try:
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203 | st = os.lstat(path)
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204 | except (os.error, AttributeError):
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205 | return False
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206 | return stat.S_ISLNK(st.st_mode)
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207 |
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208 | # Being true for dangling symbolic links is also useful.
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209 |
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210 | def lexists(path):
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211 | """Test whether a path exists. Returns True for broken symbolic links"""
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212 | try:
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213 | st = os.lstat(path)
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214 | except os.error:
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215 | return False
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216 | return True
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217 |
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218 |
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219 | # Are two filenames really pointing to the same file?
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220 |
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221 | def samefile(f1, f2):
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222 | """Test whether two pathnames reference the same actual file"""
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223 | s1 = os.stat(f1)
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224 | s2 = os.stat(f2)
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225 | return samestat(s1, s2)
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226 |
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227 |
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228 | # Are two open files really referencing the same file?
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229 | # (Not necessarily the same file descriptor!)
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230 |
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231 | def sameopenfile(fp1, fp2):
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232 | """Test whether two open file objects reference the same file"""
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233 | s1 = os.fstat(fp1)
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234 | s2 = os.fstat(fp2)
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235 | return samestat(s1, s2)
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236 |
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237 |
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238 | # Are two stat buffers (obtained from stat, fstat or lstat)
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239 | # describing the same file?
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240 |
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241 | def samestat(s1, s2):
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242 | """Test whether two stat buffers reference the same file"""
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243 | return s1.st_ino == s2.st_ino and \
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244 | s1.st_dev == s2.st_dev
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245 |
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246 |
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247 | supports_unicode_filenames = False
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248 |
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249 |
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250 | def relpath(path, start=curdir):
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251 | """Return a relative version of a path"""
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252 |
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253 | if not path:
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254 | raise ValueError("no path specified")
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255 | start_list = abspath(start).split(sep)
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256 | path_list = abspath(path).split(sep)
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257 | # Remove empty components after trailing slashes
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258 | if (start_list[-1] == ''):
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259 | start_list.pop()
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260 | if (path_list[-1] == ''):
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261 | path_list.pop()
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262 | if start_list[0].lower() != path_list[0].lower():
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263 | unc_path, rest = splitunc(path)
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264 | unc_start, rest = splitunc(start)
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265 | if bool(unc_path) ^ bool(unc_start):
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266 | raise ValueError("Cannot mix UNC and non-UNC paths (%s and %s)"
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267 | % (path, start))
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268 | else:
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269 | raise ValueError("path is on drive %s, start on drive %s"
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270 | % (path_list[0], start_list[0]))
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271 | # Work out how much of the filepath is shared by start and path.
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272 | for i in range(min(len(start_list), len(path_list))):
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273 | if start_list[i].lower() != path_list[i].lower():
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274 | break
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275 | else:
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276 | i += 1
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277 |
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278 | rel_list = [pardir] * (len(start_list)-i) + path_list[i:]
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279 | if not rel_list:
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280 | return curdir
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281 | return join(*rel_list)
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