mirror of https://github.com/python/cpython
Added ntpath.py (for os.py when used with Windows NT)
This commit is contained in:
Guido van Rossum
parent
68cfbe7c93
commit
555915a90b
|
|
@ -0,0 +1,348 @@
|
|||
# Module 'dospath' -- 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 and maps invalid consecutive characters to a single '_'.
|
||||
# Other normalizations (such as optimizing '../' away) are not allowed
|
||||
# (this is done by normpath).
|
||||
|
||||
mapchar = '_'
|
||||
|
||||
def normcase(s):
|
||||
res, s = splitdrive(s)
|
||||
for c in s:
|
||||
if c in '/\\':
|
||||
res = res + os.sep
|
||||
elif c == '.' and res[-1:] == os.sep:
|
||||
res = res + mapchar + c
|
||||
elif ord(c) < 32 or c in ' "*+,:;<=>?[]|':
|
||||
if res[-1:] != mapchar:
|
||||
res = res + mapchar
|
||||
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 pathnames.
|
||||
# Ignore the first part if the second part is absolute.
|
||||
# Insert a '/' unless the first part is empty or already ends in '/'.
|
||||
|
||||
def join(a, b):
|
||||
if isabs(b): return b
|
||||
if a == '' or a[-1:] in '/\\': return a + b
|
||||
# Note: join('x', '') returns 'x/'; is this what we want?
|
||||
return a + os.sep + b
|
||||
|
||||
|
||||
# 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 first 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 == '.' or 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 false
|
||||
|
||||
|
||||
# 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 not os.environ.has_key('HOME'):
|
||||
return path
|
||||
userhome = os.environ['HOME']
|
||||
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.
|
||||
# Also, components of the path are silently truncated to 8+3 notation.
|
||||
|
||||
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]
|
||||
elif '.' in comps[i]:
|
||||
comp = string.splitfields(comps[i], '.')
|
||||
comps[i] = comp[0][:8] + '.' + comp[1][:3]
|
||||
i = i+1
|
||||
elif len(comps[i]) > 8:
|
||||
comps[i] = comps[i][:8]
|
||||
i = i+1
|
||||
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)
|
||||
|
||||
Loading…
Reference in New Issue