blob: a0b96c7f3e2f62b3137a06295f7b79de71918263 [file] [log] [blame]
# Copyright 2014 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2
import errno
from portage import os
def first_existing(path):
Returns the first existing path element, traversing from the given
path to the root directory. A path is considered to exist if lstat
either succeeds or raises an error other than ENOENT or ESTALE.
This can be particularly useful to check if there is permission to
create a particular file or directory, without actually creating
@param path: a filesystem path
@type path: str
@rtype: str
@return: the element that exists
existing = False
for path in iter_parents(path):
existing = True
except OSError as e:
if e.errno not in (errno.ENOENT, errno.ESTALE):
existing = True
if existing:
return path
return os.sep
def iter_parents(path):
@param path: a filesystem path
@type path: str
@rtype: iterator
@return: an iterator which yields path and all parents of path,
ending with the root directory
yield path
while path != os.sep:
path = os.path.dirname(path)
yield path