Source Code for Module Ganga.Utility.ospath_fix

 1  # on some python 2.3 distributions the os.path.realpath() is broken and the symlinks are 
 2  # resolved wrt to the current working directory 
 3   
 4  import os.path 
 5   
 6 -def realpath(filename): 
 7      """Return the canonical path of the specified filename, eliminating any 
 8  symbolic links encountered in the path.""" 
 9      if os.path.isabs(filename): 
10          bits = ['/'] + filename.split('/')[1:] 
11      else: 
12          bits = [''] + filename.split('/') 
13   
14      for i in range(2, len(bits)+1): 
15          component = os.path.join(*bits[0:i]) 
16          # Resolve symbolic links. 
17          if os.path.islink(component): 
18              resolved = _resolve_link(component) 
19              if resolved is None: 
20                  # Infinite loop -- return original component + rest of the path 
21                  return os.path.abspath(os.path.join(*([component] + bits[i:]))) 
22              else: 
23                  newpath = os.path.join(*([resolved] + bits[i:])) 
24                  return realpath(newpath) 
25   
26      return os.path.abspath(filename) 
27   
28   
29 -def _resolve_link(path): 
30      """Internal helper function.  Takes a path and follows symlinks 
31      until we either arrive at something that isn't a symlink, or 
32      encounter a path we've seen before (meaning that there's a loop). 
33      """ 
34      paths_seen = [] 
35      while os.path.islink(path): 
36          if path in paths_seen: 
37              # Already seen this path, so we must have a symlink loop 
38              return None 
39          paths_seen.append(path) 
40          # Resolve where the link points to 
41          resolved = os.readlink(path) 
42          if not os.path.isabs(resolved): 
43              dir = os.path.dirname(path) 
44              path = os.path.normpath(os.path.join(dir, resolved)) 
45          else: 
46              path = os.path.normpath(resolved) 
47      return path 
48   
49  os.path.realpath = realpath 
50  os.path._resolve_link = _resolve_link 
51