mirror of https://github.com/python/cpython.git
125 lines
2.6 KiB
Python
125 lines
2.6 KiB
Python
# Module 'path' -- common operations on POSIX pathnames
|
|
|
|
import posix
|
|
|
|
|
|
# Intelligent pathname concatenation.
|
|
# Inserts a '/' unless the first part is empty or already ends in '/'.
|
|
# Ignores the first part altogether if the second part is absolute
|
|
# (begins with '/').
|
|
#
|
|
def cat(a, b):
|
|
if b[:1] = '/': return b
|
|
if a = '' or a[-1:] = '/': return a + b
|
|
return a + '/' + b
|
|
|
|
|
|
# Split a path in head (empty or ending in '/') and tail (no '/').
|
|
# The tail will be empty if the path ends in '/'.
|
|
#
|
|
def split(p):
|
|
head, tail = '', ''
|
|
for c in p:
|
|
tail = tail + c
|
|
if c = '/':
|
|
head, tail = head + tail, ''
|
|
return head, tail
|
|
|
|
|
|
# Return the tail (basename) part of a path.
|
|
#
|
|
def basename(p):
|
|
return split(p)[1]
|
|
|
|
|
|
# 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
|
|
|
|
|
|
# Does a file/directory exist?
|
|
#
|
|
def exists(path):
|
|
try:
|
|
st = posix.stat(path)
|
|
except posix.error:
|
|
return 0
|
|
return 1
|
|
|
|
|
|
# Is a path a posix directory?
|
|
#
|
|
def isdir(path):
|
|
try:
|
|
st = posix.stat(path)
|
|
except posix.error:
|
|
return 0
|
|
return st[0] / 4096 = 4 # S_IFDIR
|
|
|
|
|
|
# Is a path a symbolic link?
|
|
# This will always return false on systems where posix.lstat doesn't exist.
|
|
#
|
|
def islink(path):
|
|
try:
|
|
st = posix.lstat(path)
|
|
except (posix.error, NameError):
|
|
return 0
|
|
return st[0] / 4096 = 10 # S_IFLNK
|
|
|
|
|
|
_mounts = []
|
|
|
|
def _getmounts():
|
|
import commands, string
|
|
mounts = []
|
|
data = commands.getoutput('/etc/mount')
|
|
lines = string.splitfields(data, '\n')
|
|
for line in lines:
|
|
words = string.split(line)
|
|
if len(words) >= 3 and words[1] = 'on':
|
|
mounts.append(words[2])
|
|
return mounts
|
|
|
|
|
|
# Is a path a mount point?
|
|
# This only works for normalized, absolute paths,
|
|
# and only if the mount table as printed by /etc/mount is correct.
|
|
# Sorry.
|
|
#
|
|
def ismount(path):
|
|
if not _mounts:
|
|
_mounts[:] = _getmounts()
|
|
return path in _mounts
|
|
|
|
|
|
# Directory tree walk.
|
|
# For each directory under top (including top itself),
|
|
# func(arg, dirname, filenames) is called, where dirname
|
|
# is the name of the directory and filenames is the list of
|
|
# files (and subdirectories etc.) in the directory.
|
|
# 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 = posix.listdir(top)
|
|
except posix.error:
|
|
return
|
|
func(arg, top, names)
|
|
exceptions = ('.', '..')
|
|
for name in names:
|
|
if name not in exceptions:
|
|
name = cat(top, name)
|
|
if isdir(name):
|
|
walk(name, func, arg)
|