1 #! /usr/bin/env python3
2 
3 # linktree
4 #
5 # Make a copy of a directory tree with symbolic links to all files in the
6 # original tree.
7 # All symbolic links go to a special symbolic link at the top, so you
8 # can easily fix things if the original source tree moves.
9 # See also "mkreal".
10 #
11 # usage: mklinks oldtree newtree
12 
13 import sys, os
14 
15 LINK = '.LINK' # Name of special symlink at the top.
16 
17 debug = 0
18 
19 def main():
20     if not 3 <= len(sys.argv) <= 4:
21         print('usage:', sys.argv[0], 'oldtree newtree [linkto]')
22         return 2
23     oldtree, newtree = sys.argv[1], sys.argv[2]
24     if len(sys.argv) > 3:
25         link = sys.argv[3]
26         link_may_fail = 1
27     else:
28         link = LINK
29         link_may_fail = 0
30     if not os.path.isdir(oldtree):
31         print(oldtree + ': not a directory')
32         return 1
33     try:
34         os.mkdir(newtree, 0o777)
35     except OSError as msg:
36         print(newtree + ': cannot mkdir:', msg)
37         return 1
38     linkname = os.path.join(newtree, link)
39     try:
40         os.symlink(os.path.join(os.pardir, oldtree), linkname)
41     except OSError as msg:
42         if not link_may_fail:
43             print(linkname + ': cannot symlink:', msg)
44             return 1
45         else:
46             print(linkname + ': warning: cannot symlink:', msg)
47     linknames(oldtree, newtree, link)
48     return 0
49 
50 def linknames(old, new, link):
51     if debug: print('linknames', (old, new, link))
52     try:
53         names = os.listdir(old)
54     except OSError as msg:
55         print(old + ': warning: cannot listdir:', msg)
56         return
57     for name in names:
58         if name not in (os.curdir, os.pardir):
59             oldname = os.path.join(old, name)
60             linkname = os.path.join(link, name)
61             newname = os.path.join(new, name)
62             if debug > 1: print(oldname, newname, linkname)
63             if os.path.isdir(oldname) and \
64                not os.path.islink(oldname):
65                 try:
66                     os.mkdir(newname, 0o777)
67                     ok = 1
68                 except:
69                     print(newname + \
70                           ': warning: cannot mkdir:', msg)
71                     ok = 0
72                 if ok:
73                     linkname = os.path.join(os.pardir,
74                                             linkname)
75                     linknames(oldname, newname, linkname)
76             else:
77                 os.symlink(linkname, newname)
78 
79 if __name__ == '__main__':
80     sys.exit(main())
81