Issue #15177: Added dir_fd parameter to os.fwalk().

This commit is contained in:
Larry Hastings 2012-06-25 04:49:05 -07:00
parent 2a193a818a
commit c48fe98a7c
4 changed files with 42 additions and 14 deletions

View file

@ -422,9 +422,9 @@ def walk(top, topdown=True, onerror=None, followlinks=False):
__all__.append("walk")
if open in supports_dir_fd:
if {open, stat} <= supports_dir_fd and {listdir, stat} <= supports_fd:
def fwalk(top, topdown=True, onerror=None, followlinks=False):
def fwalk(top=".", topdown=True, onerror=None, followlinks=False, *, dir_fd=None):
"""Directory tree generator.
This behaves exactly like walk(), except that it yields a 4-tuple
@ -434,9 +434,13 @@ if open in supports_dir_fd:
`dirpath`, `dirnames` and `filenames` are identical to walk() output,
and `dirfd` is a file descriptor referring to the directory `dirpath`.
The advantage of walkfd() over walk() is that it's safe against symlink
The advantage of fwalk() over walk() is that it's safe against symlink
races (when followlinks is False).
If dir_fd is not None, it should be a file descriptor open to a directory,
and top should be relative; top will then be relative to that directory.
(dir_fd is always supported for fwalk.)
Caution:
Since fwalk() yields file descriptors, those are only valid until the
next iteration step, so you should dup() them if you want to keep them
@ -455,11 +459,11 @@ if open in supports_dir_fd:
"""
# Note: To guard against symlink races, we use the standard
# lstat()/open()/fstat() trick.
orig_st = lstat(top)
topfd = open(top, O_RDONLY)
orig_st = stat(top, follow_symlinks=False, dir_fd=dir_fd)
topfd = open(top, O_RDONLY, dir_fd=dir_fd)
try:
if (followlinks or (st.S_ISDIR(orig_st.st_mode) and
path.samestat(orig_st, fstat(topfd)))):
path.samestat(orig_st, stat(topfd)))):
yield from _fwalk(topfd, top, topdown, onerror, followlinks)
finally:
close(topfd)
@ -502,7 +506,7 @@ if open in supports_dir_fd:
onerror(err)
return
try:
if followlinks or path.samestat(orig_st, fstat(dirfd)):
if followlinks or path.samestat(orig_st, stat(dirfd)):
dirpath = path.join(toppath, name)
yield from _fwalk(dirfd, dirpath, topdown, onerror, followlinks)
finally: