1996-07-30 16:35:26 +00:00
|
|
|
# Module 'posixpath' -- common operations on Posix pathnames.
|
|
|
|
# Some of this can actually be useful on non-Posix systems too, e.g.
|
|
|
|
# for manipulation of the pathname component of URLs.
|
|
|
|
# The "os.path" name is an alias for this module on Posix systems;
|
|
|
|
# on other systems (e.g. Mac, Windows), os.path provides the same
|
|
|
|
# operations in a manner specific to that platform, and is an alias
|
|
|
|
# to another module (e.g. macpath, ntpath).
|
|
|
|
|
|
|
|
import os
|
1996-07-22 15:23:25 +00:00
|
|
|
import stat
|
|
|
|
|
|
|
|
|
|
|
|
# Normalize the case of a pathname. Trivial in Posix, string.lower on Mac.
|
|
|
|
# On MS-DOS this may also turn slashes into backslashes; however, other
|
|
|
|
# normalizations (such as optimizing '../' away) are not allowed
|
|
|
|
# (another function should be defined to do that).
|
|
|
|
|
|
|
|
def normcase(s):
|
|
|
|
return s
|
|
|
|
|
|
|
|
|
|
|
|
# Return wheter a path is absolute.
|
|
|
|
# Trivial in Posix, harder on the Mac or MS-DOS.
|
|
|
|
|
|
|
|
def isabs(s):
|
|
|
|
return s[:1] == '/'
|
|
|
|
|
|
|
|
|
1997-04-02 06:13:34 +00:00
|
|
|
# Join pathnames.
|
|
|
|
# Ignore the previous parts if a part is absolute.
|
1996-07-22 15:23:25 +00:00
|
|
|
# Insert a '/' unless the first part is empty or already ends in '/'.
|
|
|
|
|
1997-04-02 06:13:34 +00:00
|
|
|
def join(a, *p):
|
|
|
|
path = a
|
|
|
|
for b in p:
|
|
|
|
if b[:1] == '/':
|
|
|
|
path = b
|
|
|
|
elif path == '' or path[-1:] == '/':
|
|
|
|
path = path + b
|
|
|
|
else:
|
|
|
|
path = path + '/' + b
|
|
|
|
return path
|
1996-07-22 15:23:25 +00:00
|
|
|
|
|
|
|
|
|
|
|
# Split a path in head (everything up to the last '/') and tail (the
|
|
|
|
# rest). If the path ends in '/', tail will be empty. If there is no
|
|
|
|
# '/' in the path, head will be empty.
|
|
|
|
# Trailing '/'es are stripped from head unless it is the root.
|
|
|
|
|
|
|
|
def split(p):
|
|
|
|
import string
|
|
|
|
i = string.rfind(p, '/') + 1
|
|
|
|
head, tail = p[:i], p[i:]
|
|
|
|
if head and head <> '/'*len(head):
|
|
|
|
while head[-1] == '/':
|
|
|
|
head = head[:-1]
|
|
|
|
return head, tail
|
|
|
|
|
|
|
|
|
|
|
|
# Split a path in root and extension.
|
1996-08-26 18:33:32 +00:00
|
|
|
# The extension is everything starting at the last dot in the last
|
1996-07-22 15:23:25 +00:00
|
|
|
# pathname component; the root is everything before that.
|
|
|
|
# It is always true that root + ext == p.
|
|
|
|
|
|
|
|
def splitext(p):
|
|
|
|
root, ext = '', ''
|
|
|
|
for c in p:
|
|
|
|
if c == '/':
|
|
|
|
root, ext = root + ext + c, ''
|
|
|
|
elif c == '.':
|
|
|
|
if ext:
|
|
|
|
root, ext = root + ext, c
|
|
|
|
else:
|
|
|
|
ext = c
|
|
|
|
elif ext:
|
|
|
|
ext = ext + c
|
|
|
|
else:
|
|
|
|
root = root + c
|
|
|
|
return root, ext
|
|
|
|
|
|
|
|
|
|
|
|
# Split a pathname into a drive specification and the rest of the
|
|
|
|
# path. Useful on DOS/Windows/NT; on Unix, the drive is always empty.
|
|
|
|
|
|
|
|
def splitdrive(p):
|
|
|
|
return '', p
|
|
|
|
|
|
|
|
|
|
|
|
# Return the tail (basename) part of a path.
|
|
|
|
|
|
|
|
def basename(p):
|
|
|
|
return split(p)[1]
|
|
|
|
|
|
|
|
|
|
|
|
# Return the head (dirname) part of a path.
|
|
|
|
|
|
|
|
def dirname(p):
|
|
|
|
return split(p)[0]
|
|
|
|
|
|
|
|
|
|
|
|
# Return the longest prefix of all list elements.
|
|
|
|
|
|
|
|
def commonprefix(m):
|
|
|
|
if not m: return ''
|
|
|
|
prefix = m[0]
|
|
|
|
for item in m:
|
|
|
|
for i in range(len(prefix)):
|
|
|
|
if prefix[:i+1] <> item[:i+1]:
|
|
|
|
prefix = prefix[:i]
|
|
|
|
if i == 0: return ''
|
|
|
|
break
|
|
|
|
return prefix
|
|
|
|
|
|
|
|
|
|
|
|
# Is a path a symbolic link?
|
1996-07-30 16:35:26 +00:00
|
|
|
# This will always return false on systems where os.lstat doesn't exist.
|
1996-07-22 15:23:25 +00:00
|
|
|
|
|
|
|
def islink(path):
|
|
|
|
try:
|
1996-07-30 16:35:26 +00:00
|
|
|
st = os.lstat(path)
|
|
|
|
except (os.error, AttributeError):
|
1996-07-22 15:23:25 +00:00
|
|
|
return 0
|
|
|
|
return stat.S_ISLNK(st[stat.ST_MODE])
|
|
|
|
|
|
|
|
|
|
|
|
# Does a path exist?
|
|
|
|
# This is false for dangling symbolic links.
|
|
|
|
|
|
|
|
def exists(path):
|
|
|
|
try:
|
1996-07-30 16:35:26 +00:00
|
|
|
st = os.stat(path)
|
|
|
|
except os.error:
|
1996-07-22 15:23:25 +00:00
|
|
|
return 0
|
|
|
|
return 1
|
|
|
|
|
|
|
|
|
1996-07-30 16:35:26 +00:00
|
|
|
# Is a path a directory?
|
1996-07-22 15:23:25 +00:00
|
|
|
# This follows symbolic links, so both islink() and isdir() can be true
|
|
|
|
# for the same path.
|
|
|
|
|
|
|
|
def isdir(path):
|
|
|
|
try:
|
1996-07-30 16:35:26 +00:00
|
|
|
st = os.stat(path)
|
|
|
|
except os.error:
|
1996-07-22 15:23:25 +00:00
|
|
|
return 0
|
|
|
|
return stat.S_ISDIR(st[stat.ST_MODE])
|
|
|
|
|
|
|
|
|
|
|
|
# Is a path a regular file?
|
|
|
|
# This follows symbolic links, so both islink() and isfile() can be true
|
|
|
|
# for the same path.
|
|
|
|
|
|
|
|
def isfile(path):
|
|
|
|
try:
|
1996-07-30 16:35:26 +00:00
|
|
|
st = os.stat(path)
|
|
|
|
except os.error:
|
1996-07-22 15:23:25 +00:00
|
|
|
return 0
|
|
|
|
return stat.S_ISREG(st[stat.ST_MODE])
|
|
|
|
|
|
|
|
|
|
|
|
# Are two filenames really pointing to the same file?
|
|
|
|
|
|
|
|
def samefile(f1, f2):
|
1996-07-30 16:35:26 +00:00
|
|
|
s1 = os.stat(f1)
|
|
|
|
s2 = os.stat(f2)
|
1996-07-22 15:23:25 +00:00
|
|
|
return samestat(s1, s2)
|
|
|
|
|
|
|
|
|
|
|
|
# Are two open files really referencing the same file?
|
|
|
|
# (Not necessarily the same file descriptor!)
|
|
|
|
|
|
|
|
def sameopenfile(fp1, fp2):
|
1996-07-30 16:35:26 +00:00
|
|
|
s1 = os.fstat(fp1)
|
|
|
|
s2 = os.fstat(fp2)
|
1996-07-22 15:23:25 +00:00
|
|
|
return samestat(s1, s2)
|
|
|
|
|
|
|
|
|
|
|
|
# Are two stat buffers (obtained from stat, fstat or lstat)
|
|
|
|
# describing the same file?
|
|
|
|
|
|
|
|
def samestat(s1, s2):
|
|
|
|
return s1[stat.ST_INO] == s2[stat.ST_INO] and \
|
|
|
|
s1[stat.ST_DEV] == s2[stat.ST_DEV]
|
|
|
|
|
|
|
|
|
|
|
|
# Is a path a mount point?
|
1996-07-30 16:35:26 +00:00
|
|
|
# (Does this work for all UNIXes? Is it even guaranteed to work by Posix?)
|
1996-07-22 15:23:25 +00:00
|
|
|
|
|
|
|
def ismount(path):
|
|
|
|
try:
|
1996-07-30 16:35:26 +00:00
|
|
|
s1 = os.stat(path)
|
|
|
|
s2 = os.stat(join(path, '..'))
|
|
|
|
except os.error:
|
1996-07-22 15:23:25 +00:00
|
|
|
return 0 # It doesn't exist -- so not a mount point :-)
|
|
|
|
dev1 = s1[stat.ST_DEV]
|
|
|
|
dev2 = s2[stat.ST_DEV]
|
|
|
|
if dev1 != dev2:
|
|
|
|
return 1 # path/.. on a different device as path
|
|
|
|
ino1 = s1[stat.ST_INO]
|
|
|
|
ino2 = s2[stat.ST_INO]
|
|
|
|
if ino1 == ino2:
|
|
|
|
return 1 # path/.. is the same i-node as path
|
|
|
|
return 0
|
|
|
|
|
|
|
|
|
|
|
|
# Directory tree walk.
|
|
|
|
# For each directory under top (including top itself, but excluding
|
|
|
|
# '.' and '..'), func(arg, dirname, filenames) is called, where
|
|
|
|
# dirname is the name of the directory and filenames is the list
|
|
|
|
# files files (and subdirectories etc.) in the directory.
|
|
|
|
# The func may modify the filenames list, to implement a filter,
|
|
|
|
# or to impose a different order of visiting.
|
|
|
|
|
|
|
|
def walk(top, func, arg):
|
|
|
|
try:
|
1996-07-30 16:35:26 +00:00
|
|
|
names = os.listdir(top)
|
|
|
|
except os.error:
|
1996-07-22 15:23:25 +00:00
|
|
|
return
|
|
|
|
func(arg, top, names)
|
|
|
|
exceptions = ('.', '..')
|
|
|
|
for name in names:
|
|
|
|
if name not in exceptions:
|
|
|
|
name = join(top, name)
|
|
|
|
if isdir(name) and not islink(name):
|
|
|
|
walk(name, func, arg)
|
|
|
|
|
|
|
|
|
|
|
|
# Expand paths beginning with '~' or '~user'.
|
|
|
|
# '~' means $HOME; '~user' means that user's home directory.
|
|
|
|
# If the path doesn't begin with '~', or if the user or $HOME is unknown,
|
|
|
|
# the path is returned unchanged (leaving error reporting to whatever
|
|
|
|
# function is called with the expanded path as argument).
|
|
|
|
# See also module 'glob' for expansion of *, ? and [...] in pathnames.
|
|
|
|
# (A function should also be defined to do full *sh-style environment
|
|
|
|
# variable expansion.)
|
|
|
|
|
|
|
|
def expanduser(path):
|
|
|
|
if path[:1] <> '~':
|
|
|
|
return path
|
|
|
|
i, n = 1, len(path)
|
|
|
|
while i < n and path[i] <> '/':
|
|
|
|
i = i+1
|
|
|
|
if i == 1:
|
1996-07-30 16:35:26 +00:00
|
|
|
if not os.environ.has_key('HOME'):
|
1996-07-22 15:23:25 +00:00
|
|
|
return path
|
1996-07-30 16:35:26 +00:00
|
|
|
userhome = os.environ['HOME']
|
1996-07-22 15:23:25 +00:00
|
|
|
else:
|
|
|
|
import pwd
|
|
|
|
try:
|
|
|
|
pwent = pwd.getpwnam(path[1:i])
|
|
|
|
except KeyError:
|
|
|
|
return path
|
|
|
|
userhome = pwent[5]
|
|
|
|
if userhome[-1:] == '/': i = i+1
|
|
|
|
return userhome + path[i:]
|
|
|
|
|
|
|
|
|
|
|
|
# Expand paths containing shell variable substitutions.
|
|
|
|
# This expands the forms $variable and ${variable} only.
|
|
|
|
# Non-existant variables are left unchanged.
|
|
|
|
|
|
|
|
_varprog = None
|
|
|
|
|
|
|
|
def expandvars(path):
|
|
|
|
global _varprog
|
|
|
|
if '$' not in path:
|
|
|
|
return path
|
|
|
|
if not _varprog:
|
1997-11-26 15:44:34 +00:00
|
|
|
import re
|
|
|
|
_varprog = re.compile(r'\$(\w+|\{[^}]*\})')
|
1996-07-22 15:23:25 +00:00
|
|
|
i = 0
|
|
|
|
while 1:
|
1997-11-26 15:44:34 +00:00
|
|
|
m = _varprog.search(path, i)
|
|
|
|
if not m:
|
1996-07-22 15:23:25 +00:00
|
|
|
break
|
1997-11-26 15:44:34 +00:00
|
|
|
i, j = m.span(0)
|
|
|
|
name = m.group(1)
|
1996-07-22 15:23:25 +00:00
|
|
|
if name[:1] == '{' and name[-1:] == '}':
|
|
|
|
name = name[1:-1]
|
1996-07-30 16:35:26 +00:00
|
|
|
if os.environ.has_key(name):
|
1996-07-22 15:23:25 +00:00
|
|
|
tail = path[j:]
|
1996-07-30 16:35:26 +00:00
|
|
|
path = path[:i] + os.environ[name]
|
1996-07-22 15:23:25 +00:00
|
|
|
i = len(path)
|
|
|
|
path = path + tail
|
|
|
|
else:
|
|
|
|
i = j
|
|
|
|
return path
|
|
|
|
|
|
|
|
|
|
|
|
# Normalize a path, e.g. A//B, A/./B and A/foo/../B all become A/B.
|
|
|
|
# It should be understood that this may change the meaning of the path
|
|
|
|
# if it contains symbolic links!
|
|
|
|
|
|
|
|
def normpath(path):
|
|
|
|
import string
|
|
|
|
# Treat initial slashes specially
|
|
|
|
slashes = ''
|
|
|
|
while path[:1] == '/':
|
|
|
|
slashes = slashes + '/'
|
|
|
|
path = path[1:]
|
|
|
|
comps = string.splitfields(path, '/')
|
|
|
|
i = 0
|
|
|
|
while i < len(comps):
|
|
|
|
if comps[i] == '.':
|
|
|
|
del comps[i]
|
|
|
|
elif comps[i] == '..' and i > 0 and \
|
|
|
|
comps[i-1] not in ('', '..'):
|
|
|
|
del comps[i-1:i+1]
|
|
|
|
i = i-1
|
|
|
|
elif comps[i] == '' and i > 0 and comps[i-1] <> '':
|
|
|
|
del comps[i]
|
|
|
|
else:
|
|
|
|
i = i+1
|
|
|
|
# If the path is now empty, substitute '.'
|
|
|
|
if not comps and not slashes:
|
|
|
|
comps.append('.')
|
|
|
|
return slashes + string.joinfields(comps, '/')
|