353 lines
8.3 KiB
Python
353 lines
8.3 KiB
Python
# Module 'ntpath' -- common operations on DOS pathnames
|
|
|
|
import os
|
|
import stat
|
|
import string
|
|
|
|
|
|
# Normalize the case of a pathname.
|
|
# On MS-DOS it maps the pathname to lowercase, turns slashes into
|
|
# backslashes.
|
|
# Other normalizations (such as optimizing '../' away) are not allowed
|
|
# (this is done by normpath).
|
|
# Previously, this version mapped invalid consecutive characters to a
|
|
# single '_', but this has been removed. This functionality should
|
|
# possibly be added as a new function.
|
|
|
|
def normcase(s):
|
|
res, s = splitdrive(s)
|
|
for c in s:
|
|
if c in '/\\':
|
|
res = res + os.sep
|
|
else:
|
|
res = res + c
|
|
return string.lower(res)
|
|
|
|
|
|
# Return wheter a path is absolute.
|
|
# Trivial in Posix, harder on the Mac or MS-DOS.
|
|
# For DOS it is absolute if it starts with a slash or backslash (current
|
|
# volume), or if a pathname after the volume letter and colon starts with
|
|
# a slash or backslash.
|
|
|
|
def isabs(s):
|
|
s = splitdrive(s)[1]
|
|
return s != '' and s[:1] in '/\\'
|
|
|
|
|
|
# Join two (or more) paths.
|
|
|
|
def join(a, *p):
|
|
path = a
|
|
for b in p:
|
|
if isabs(b):
|
|
path = b
|
|
elif path == '' or path[-1:] in '/\\':
|
|
path = path + b
|
|
else:
|
|
path = path + os.sep + b
|
|
return path
|
|
|
|
|
|
# Split a path in a drive specification (a drive letter followed by a
|
|
# colon) and the path specification.
|
|
# It is always true that drivespec + pathspec == p
|
|
def splitdrive(p):
|
|
if p[1:2] == ':':
|
|
return p[0:2], p[2:]
|
|
return '', p
|
|
|
|
|
|
# Split a path in head (everything up to the last '/') and tail (the
|
|
# rest). If the original path ends in '/' but is not the root, this
|
|
# '/' is stripped. After the trailing '/' is stripped, the invariant
|
|
# join(head, tail) == p holds.
|
|
# The resulting head won't end in '/' unless it is the root.
|
|
|
|
def split(p):
|
|
d, p = splitdrive(p)
|
|
slashes = ''
|
|
while p and p[-1:] in '/\\':
|
|
slashes = slashes + p[-1]
|
|
p = p[:-1]
|
|
if p == '':
|
|
p = p + slashes
|
|
head, tail = '', ''
|
|
for c in p:
|
|
tail = tail + c
|
|
if c in '/\\':
|
|
head, tail = head + tail, ''
|
|
slashes = ''
|
|
while head and head[-1:] in '/\\':
|
|
slashes = slashes + head[-1]
|
|
head = head[:-1]
|
|
if head == '':
|
|
head = head + slashes
|
|
return d + head, tail
|
|
|
|
|
|
# Split a path in root and extension.
|
|
# The extension is everything starting at the last dot in the last
|
|
# 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 in ['/','\\']:
|
|
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
|
|
|
|
|
|
# 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?
|
|
# This will always return false on systems where posix.lstat doesn't exist.
|
|
|
|
def islink(path):
|
|
return 0
|
|
|
|
|
|
# Does a path exist?
|
|
# This is false for dangling symbolic links.
|
|
|
|
def exists(path):
|
|
try:
|
|
st = os.stat(path)
|
|
except os.error:
|
|
return 0
|
|
return 1
|
|
|
|
|
|
# Is a path a dos directory?
|
|
# This follows symbolic links, so both islink() and isdir() can be true
|
|
# for the same path.
|
|
|
|
def isdir(path):
|
|
try:
|
|
st = os.stat(path)
|
|
except os.error:
|
|
return 0
|
|
return stat.S_ISDIR(st[stat.ST_MODE])
|
|
|
|
|
|
# Is a path a regular file?
|
|
# This follows symbolic links, so both islink() and isdir() can be true
|
|
# for the same path.
|
|
|
|
def isfile(path):
|
|
try:
|
|
st = os.stat(path)
|
|
except os.error:
|
|
return 0
|
|
return stat.S_ISREG(st[stat.ST_MODE])
|
|
|
|
|
|
# Are two filenames really pointing to the same file?
|
|
|
|
def samefile(f1, f2):
|
|
s1 = os.stat(f1)
|
|
s2 = os.stat(f2)
|
|
return samestat(s1, s2)
|
|
|
|
|
|
# Are two open files really referencing the same file?
|
|
# (Not necessarily the same file descriptor!)
|
|
# XXX THIS IS BROKEN UNDER DOS! ST_INO seems to indicate number of reads?
|
|
|
|
def sameopenfile(fp1, fp2):
|
|
s1 = os.fstat(fp1.fileno())
|
|
s2 = os.fstat(fp2.fileno())
|
|
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?
|
|
# XXX This degenerates in: 'is this the root?' on DOS
|
|
|
|
def ismount(path):
|
|
return isabs(splitdrive(path)[1])
|
|
|
|
|
|
# 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:
|
|
names = os.listdir(top)
|
|
except os.error:
|
|
return
|
|
func(arg, top, names)
|
|
exceptions = ('.', '..')
|
|
for name in names:
|
|
if name not in exceptions:
|
|
name = join(top, name)
|
|
if isdir(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] not in '/\\':
|
|
i = i+1
|
|
if i == 1:
|
|
if os.environ.has_key('HOME'):
|
|
userhome = os.environ['HOME']
|
|
elif not os.environ.has_key('HOMEPATH'):
|
|
return path
|
|
else:
|
|
try:
|
|
drive=os.environ['HOMEDRIVE']
|
|
except KeyError:
|
|
drive = ''
|
|
userhome = join(drive, os.environ['HOMEPATH'])
|
|
else:
|
|
return path
|
|
return userhome + path[i:]
|
|
|
|
|
|
# Expand paths containing shell variable substitutions.
|
|
# The following rules apply:
|
|
# - no expansion within single quotes
|
|
# - no escape character, except for '$$' which is translated into '$'
|
|
# - ${varname} is accepted.
|
|
# - varnames can be made out of letters, digits and the character '_'
|
|
# XXX With COMMAND.COM you can use any characters in a variable name,
|
|
# XXX except '^|<>='.
|
|
|
|
varchars = string.letters + string.digits + '_-'
|
|
|
|
def expandvars(path):
|
|
if '$' not in path:
|
|
return path
|
|
res = ''
|
|
index = 0
|
|
pathlen = len(path)
|
|
while index < pathlen:
|
|
c = path[index]
|
|
if c == '\'': # no expansion within single quotes
|
|
path = path[index + 1:]
|
|
pathlen = len(path)
|
|
try:
|
|
index = string.index(path, '\'')
|
|
res = res + '\'' + path[:index + 1]
|
|
except string.index_error:
|
|
res = res + path
|
|
index = pathlen -1
|
|
elif c == '$': # variable or '$$'
|
|
if path[index + 1:index + 2] == '$':
|
|
res = res + c
|
|
index = index + 1
|
|
elif path[index + 1:index + 2] == '{':
|
|
path = path[index+2:]
|
|
pathlen = len(path)
|
|
try:
|
|
index = string.index(path, '}')
|
|
var = path[:index]
|
|
if os.environ.has_key(var):
|
|
res = res + os.environ[var]
|
|
except string.index_error:
|
|
res = res + path
|
|
index = pathlen - 1
|
|
else:
|
|
var = ''
|
|
index = index + 1
|
|
c = path[index:index + 1]
|
|
while c != '' and c in varchars:
|
|
var = var + c
|
|
index = index + 1
|
|
c = path[index:index + 1]
|
|
if os.environ.has_key(var):
|
|
res = res + os.environ[var]
|
|
if c != '':
|
|
res = res + c
|
|
else:
|
|
res = res + c
|
|
index = index + 1
|
|
return res
|
|
|
|
|
|
# Normalize a path, e.g. A//B, A/./B and A/foo/../B all become A/B.
|
|
# Previously, this function also truncated pathnames to 8+3 format,
|
|
# but as this module is called "ntpath", that's obviously wrong!
|
|
|
|
def normpath(path):
|
|
path = normcase(path)
|
|
prefix, path = splitdrive(path)
|
|
while path[:1] == os.sep:
|
|
prefix = prefix + os.sep
|
|
path = path[1:]
|
|
comps = string.splitfields(path, os.sep)
|
|
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 prefix and not comps:
|
|
comps.append('.')
|
|
return prefix + string.joinfields(comps, os.sep)
|