Giampaolo Rodola' wrote: > On 1 Dic, 00:10, "Martin v. L�wis" <[EMAIL PROTECTED]> wrote: > > > I would like to know if such function would be correct for verifying > > > if a link is broken and/or circular. > > > > > def isvalidlink(path): > > > assert os.path.islink(path) > > > try: > > > os.stat(path) > > > except os.error: > > > return 1 > > > return 0 > > > > You meant to flip the result values, right? 1 should mean that the > > link is value, and 0 that it is not. > > > > Mostly. If the link is correct, but you don't have permission to stat > > the target file, you get 0. OTOH, in that case, you have no way of > > finding out whether the link *is* correct. > > > > Still, you could try to detect the errnos that indicate a problem > > with the link itself, and pass all other errors through. > > > > Regards, > > Martin > > Mmmm... do you mean something like this? > Could it be ok? > >
I think he meant something like this (see below): > > import os, errno > > def isvalidlink(path): > assert os.path.lexists(path) > try: > os.stat(path) > except os.error, err: > # broken link > # "No such file or directory" > if err.errno == errno.ENOENT: > return 1 Right, except that it should be return 0 (or preferably return False) unless you want inverted logic. > # circular link > # "Too many levels of symlinks" > elif err.errno == errno.ELOOP: > return 2 Change to return 1/True (inverted) or return 0/False (not inverted) > # something else occurred, > # assume it as invalid anyway > else: > return 3 Change "return 3" to "raise", so the exception gets propagated. > return 0 Again, if you do not want the logic to be inverted, use return 1/True instead --Nathan Davis -- http://mail.python.org/mailman/listinfo/python-list
