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  1. import re
  2.  
  3. test_paths = [
  4. 	'a/b/c/../../x',
  5. 	'a/b/c/../../x/..',
  6. 	'a/b/c/../../../x',
  7. 	'a/b/c/../../../../x',
  8. 	'a/b/c/../../../../x/',
  9. 	'a/b/c/../../../../x///',
  10. 	'a/b/c/../../q/a/b/c/../../../../../x',
  11. 	'//a/b/c/../../q/a/././b/./c/../../..////../../../../../x',
  12. ]
  13.  
  14. for path in test_paths:
  15. 	print "INPUT: ", path
  16. 	path = '/' + path							# secure from missing root
  17. 	path = re.sub(r'/+', '/', path)				# remove any slash repetitions
  18. 	path = re.sub(r'(?<!\.)\.(?:/|$)', '', path)	# remove any "./"
  19. 	while True:									# remove any "dir/../"
  20. 		pp = re.sub(r'\w+\/\.\.(?:/|$)', '', path)
  21. 		if pp == path:							# NB: we have to do this in a
  22. 			break								# loop until path remains unchanged
  23. 		else:									# to cope with input like this:
  24. 			path = pp							# '/a/b/../c/../../d'
  25. 	path = re.sub(r'\.\.(?:/|$)', '', path)		# remove oustanding '../' (cf. '/a/../../b')
  26. 	path = re.sub(r'/$', '', path)				# remove trailing slash
  27. 	print "CANONICAL: ", path
Success #stdin #stdout 0s 23352KB
comments (?)
stdin 
Standard input is empty
stdout 
INPUT:  a/b/c/../../x
CANONICAL:  /a/x
INPUT:  a/b/c/../../x/..
CANONICAL:  /a
INPUT:  a/b/c/../../../x
CANONICAL:  /x
INPUT:  a/b/c/../../../../x
CANONICAL:  /x
INPUT:  a/b/c/../../../../x/
CANONICAL:  /x
INPUT:  a/b/c/../../../../x///
CANONICAL:  /x
INPUT:  a/b/c/../../q/a/b/c/../../../../../x
CANONICAL:  /x
INPUT:  //a/b/c/../../q/a/././b/./c/../../..////../../../../../x
CANONICAL:  /x
https://ideone.com/I5B084
language:
Python (cpython 2.7.16)
created:
7 years ago
visibility:
public

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