cpython/Lib/macpath.py

134 lines
2.8 KiB
Python

# module 'macpath' -- pathname (or -related) operations for the Macintosh
import string
import mac
from stat import *
# Normalize the case of a pathname. Dummy in Posix, but string.lower here.
normcase = string.lower
# Return true if a path is absolute.
# On the Mac, relative paths begin with a colon,
# but as a special case, paths with no colons at all are also relative.
# Anything else is absolute (the string up to the first colon is the
# volume name).
def isabs(s):
return ':' in s and s[0] <> ':'
# Join two pathnames.
# The result is equivalent to what the second pathname would refer to
# if the first pathname were the current directory.
def join(s, t):
if (not s) or isabs(t): return t
if t[:1] == ':': t = t[1:]
if ':' not in s:
s = ':' + s
if s[-1:] <> ':':
s = s + ':'
return s + t
# Split a pathname in two parts: the directory leading up to the final bit,
# and the basename (the filename, without colons, in that directory).
# The result (s, t) is such that join(s, t) yields the original argument.
def split(s):
if ':' not in s: return '', s
colon = 0
for i in range(len(s)):
if s[i] == ':': colon = i+1
return s[:colon-1], s[colon:]
# Short interfaces to split()
def dirname(s): return split(s)[0]
def basename(s): return split(s)[1]
# XXX This is undocumented and may go away!
# Normalize a pathname: get rid of '::' sequences by backing up,
# e.g., 'foo:bar::bletch' becomes 'foo:bletch'.
# Raise the exception norm_error below if backing up is impossible,
# e.g., for '::foo'.
norm_error = 'macpath.norm_error: path cannot be normalized'
def norm(s):
import string
if ':' not in s:
return ':' + s
f = string.splitfields(s, ':')
pre = []
post = []
if not f[0]:
pre = f[:1]
f = f[1:]
if not f[len(f)-1]:
post = f[-1:]
f = f[:-1]
res = []
for seg in f:
if seg:
res.append(seg)
else:
if not res: raise norm_error, 'path starts with ::'
del res[len(res)-1]
if not (pre or res):
raise norm_error, 'path starts with volume::'
if pre: res = pre + res
if post: res = res + post
s = res[0]
for seg in res[1:]:
s = s + ':' + seg
return s
# Return true if the pathname refers to an existing directory.
def isdir(s):
try:
st = mac.stat(s)
except mac.error:
return 0
return S_ISDIR(st[ST_MODE])
# Return true if the pathname refers to a symbolic link.
# (Always false on the Mac, until we understand Aliases.)
def islink(s):
return 0
# Return true if the pathname refers to an existing regular file.
def isfile(s):
try:
st = mac.stat(s)
except mac.error:
return 0
return S_ISREG(st[ST_MODE])
# Return true if the pathname refers to an existing file or directory.
def exists(s):
try:
st = mac.stat(s)
except mac.error:
return 0
return 1
# Normalize path, removing things like ...:A:..:... (yet to be written)
def normpath(s):
return s