mirror of https://github.com/python/cpython.git
176 lines
3.7 KiB
Python
176 lines
3.7 KiB
Python
# Module 'path' -- common operations on POSIX pathnames
|
|
|
|
import posix
|
|
import stat
|
|
|
|
|
|
# Join two pathnames.
|
|
# Insert a '/' unless the first part is empty or already ends in '/'.
|
|
# Ignore the first part altogether if the second part is absolute
|
|
# (begins with '/').
|
|
#
|
|
def join(a, b):
|
|
if b[:1] == '/': return b
|
|
if a == '' or a[-1:] == '/': return a + b
|
|
# Note: join('x', '') returns 'x/'; is this what we want?
|
|
return a + '/' + b
|
|
|
|
|
|
cat = join # For compatibility
|
|
|
|
|
|
# Split a path in head (empty or ending in '/') and tail (no '/').
|
|
# The tail will be empty if the path ends in '/'.
|
|
# It is always true that head+tail = p.
|
|
#
|
|
def split(p):
|
|
head, tail = '', ''
|
|
for c in p:
|
|
tail = tail + c
|
|
if c == '/':
|
|
head, tail = head + tail, ''
|
|
return 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 == '/':
|
|
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 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 stat.S_ISDIR(st[stat.ST_MODE])
|
|
|
|
|
|
# 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, AttributeError):
|
|
return 0
|
|
return stat.S_ISLNK(st[stat.ST_MODE])
|
|
|
|
|
|
# Are two filenames really pointing to the same file?
|
|
#
|
|
def samefile(f1, f2):
|
|
s1 = posix.stat(f1)
|
|
s2 = posix.stat(f2)
|
|
return samestat(s1, s2)
|
|
|
|
|
|
# Are two open files really referencing the same file?
|
|
# (Not necessarily the same file descriptor!)
|
|
# XXX Oops, posix.fstat() doesn't exist yet!
|
|
#
|
|
def sameopenfile(fp1, fp2):
|
|
s1 = posix.fstat(fp1)
|
|
s2 = posix.fstat(fp2)
|
|
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.STD_DEV]
|
|
|
|
|
|
# Subroutine and global data used by ismount().
|
|
|
|
_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 = join(top, name)
|
|
if isdir(name):
|
|
walk(name, func, arg)
|