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- # 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.
- # 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):
- return string.lower(string.replace(s, "/", "\\"))
-
-
- # 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). 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)
- # set i to index beyond p's last slash
- i = len(p)
- while i and p[i-1] not in '/\\':
- i = i - 1
- head, tail = p[:i], p[i:] # now tail has no slashes
- # remove trailing slashes from head, unless it's all slashes
- head2 = head
- while head2 and head2[-1] in '/\\':
- head2 = head2[:-1]
- head = head2 or head
- 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
-
-
- # Get size, mtime, atime of files.
-
- def getsize(filename):
- """Return the size of a file, reported by os.stat()."""
- st = os.stat(filename)
- return st[stat.ST_SIZE]
-
- def getmtime(filename):
- """Return the last modification time of a file, reported by os.stat()."""
- st = os.stat(filename)
- return st[stat.ST_MTIME]
-
- def getatime(filename):
- """Return the last access time of a file, reported by os.stat()."""
- st = os.stat(filename)
- return st[stat.ST_MTIME]
-
-
- # 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])
-
-
- # 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 = string.replace(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)
-
-
-
- # Return an absolute path.
- def abspath(path):
- if not isabs(path):
- path = join(os.getcwd(), path)
- return normpath(path)
-