mirror of
https://github.com/python/cpython.git
synced 2024-12-05 07:43:50 +08:00
22cd768177
on file.__methods__. Since the docs say "This module will become obsolete in a future release", this is just a quick hack to stop it from blowing up. If you care about this module, test it! It doesn't make much sense on Windows.
234 lines
7.6 KiB
Python
234 lines
7.6 KiB
Python
"""Extended file operations available in POSIX.
|
|
|
|
f = posixfile.open(filename, [mode, [bufsize]])
|
|
will create a new posixfile object
|
|
|
|
f = posixfile.fileopen(fileobject)
|
|
will create a posixfile object from a builtin file object
|
|
|
|
f.file()
|
|
will return the original builtin file object
|
|
|
|
f.dup()
|
|
will return a new file object based on a new filedescriptor
|
|
|
|
f.dup2(fd)
|
|
will return a new file object based on the given filedescriptor
|
|
|
|
f.flags(mode)
|
|
will turn on the associated flag (merge)
|
|
mode can contain the following characters:
|
|
|
|
(character representing a flag)
|
|
a append only flag
|
|
c close on exec flag
|
|
n no delay flag
|
|
s synchronization flag
|
|
(modifiers)
|
|
! turn flags 'off' instead of default 'on'
|
|
= copy flags 'as is' instead of default 'merge'
|
|
? return a string in which the characters represent the flags
|
|
that are set
|
|
|
|
note: - the '!' and '=' modifiers are mutually exclusive.
|
|
- the '?' modifier will return the status of the flags after they
|
|
have been changed by other characters in the mode string
|
|
|
|
f.lock(mode [, len [, start [, whence]]])
|
|
will (un)lock a region
|
|
mode can contain the following characters:
|
|
|
|
(character representing type of lock)
|
|
u unlock
|
|
r read lock
|
|
w write lock
|
|
(modifiers)
|
|
| wait until the lock can be granted
|
|
? return the first lock conflicting with the requested lock
|
|
or 'None' if there is no conflict. The lock returned is in the
|
|
format (mode, len, start, whence, pid) where mode is a
|
|
character representing the type of lock ('r' or 'w')
|
|
|
|
note: - the '?' modifier prevents a region from being locked; it is
|
|
query only
|
|
"""
|
|
|
|
class _posixfile_:
|
|
"""File wrapper class that provides extra POSIX file routines."""
|
|
|
|
states = ['open', 'closed']
|
|
|
|
#
|
|
# Internal routines
|
|
#
|
|
def __repr__(self):
|
|
file = self._file_
|
|
return "<%s posixfile '%s', mode '%s' at %s>" % \
|
|
(self.states[file.closed], file.name, file.mode, \
|
|
hex(id(self))[2:])
|
|
|
|
#
|
|
# Initialization routines
|
|
#
|
|
def open(self, name, mode='r', bufsize=-1):
|
|
import __builtin__
|
|
return self.fileopen(__builtin__.open(name, mode, bufsize))
|
|
|
|
def fileopen(self, file):
|
|
import types
|
|
if `type(file)` != "<type 'file'>":
|
|
raise TypeError, 'posixfile.fileopen() arg must be file object'
|
|
self._file_ = file
|
|
# Copy basic file methods
|
|
for maybemethod in dir(file):
|
|
if not maybemethod.startswith('_'):
|
|
attr = getattr(file, maybemethod)
|
|
if isinstance(attr, types.BuiltinMethodType):
|
|
setattr(self, maybemethod, attr)
|
|
return self
|
|
|
|
#
|
|
# New methods
|
|
#
|
|
def file(self):
|
|
return self._file_
|
|
|
|
def dup(self):
|
|
import posix
|
|
|
|
if not hasattr(posix, 'fdopen'):
|
|
raise AttributeError, 'dup() method unavailable'
|
|
|
|
return posix.fdopen(posix.dup(self._file_.fileno()), self._file_.mode)
|
|
|
|
def dup2(self, fd):
|
|
import posix
|
|
|
|
if not hasattr(posix, 'fdopen'):
|
|
raise AttributeError, 'dup() method unavailable'
|
|
|
|
posix.dup2(self._file_.fileno(), fd)
|
|
return posix.fdopen(fd, self._file_.mode)
|
|
|
|
def flags(self, *which):
|
|
import fcntl, os
|
|
|
|
if which:
|
|
if len(which) > 1:
|
|
raise TypeError, 'Too many arguments'
|
|
which = which[0]
|
|
else: which = '?'
|
|
|
|
l_flags = 0
|
|
if 'n' in which: l_flags = l_flags | os.O_NDELAY
|
|
if 'a' in which: l_flags = l_flags | os.O_APPEND
|
|
if 's' in which: l_flags = l_flags | os.O_SYNC
|
|
|
|
file = self._file_
|
|
|
|
if '=' not in which:
|
|
cur_fl = fcntl.fcntl(file.fileno(), fcntl.F_GETFL, 0)
|
|
if '!' in which: l_flags = cur_fl & ~ l_flags
|
|
else: l_flags = cur_fl | l_flags
|
|
|
|
l_flags = fcntl.fcntl(file.fileno(), fcntl.F_SETFL, l_flags)
|
|
|
|
if 'c' in which:
|
|
arg = ('!' not in which) # 0 is don't, 1 is do close on exec
|
|
l_flags = fcntl.fcntl(file.fileno(), fcntl.F_SETFD, arg)
|
|
|
|
if '?' in which:
|
|
which = '' # Return current flags
|
|
l_flags = fcntl.fcntl(file.fileno(), fcntl.F_GETFL, 0)
|
|
if os.O_APPEND & l_flags: which = which + 'a'
|
|
if fcntl.fcntl(file.fileno(), fcntl.F_GETFD, 0) & 1:
|
|
which = which + 'c'
|
|
if os.O_NDELAY & l_flags: which = which + 'n'
|
|
if os.O_SYNC & l_flags: which = which + 's'
|
|
return which
|
|
|
|
def lock(self, how, *args):
|
|
import struct, fcntl
|
|
|
|
if 'w' in how: l_type = fcntl.F_WRLCK
|
|
elif 'r' in how: l_type = fcntl.F_RDLCK
|
|
elif 'u' in how: l_type = fcntl.F_UNLCK
|
|
else: raise TypeError, 'no type of lock specified'
|
|
|
|
if '|' in how: cmd = fcntl.F_SETLKW
|
|
elif '?' in how: cmd = fcntl.F_GETLK
|
|
else: cmd = fcntl.F_SETLK
|
|
|
|
l_whence = 0
|
|
l_start = 0
|
|
l_len = 0
|
|
|
|
if len(args) == 1:
|
|
l_len = args[0]
|
|
elif len(args) == 2:
|
|
l_len, l_start = args
|
|
elif len(args) == 3:
|
|
l_len, l_start, l_whence = args
|
|
elif len(args) > 3:
|
|
raise TypeError, 'too many arguments'
|
|
|
|
# Hack by davem@magnet.com to get locking to go on freebsd;
|
|
# additions for AIX by Vladimir.Marangozov@imag.fr
|
|
import sys, os
|
|
if sys.platform in ('netbsd1',
|
|
'openbsd2',
|
|
'freebsd2', 'freebsd3', 'freebsd4', 'freebsd5',
|
|
'bsdos2', 'bsdos3', 'bsdos4'):
|
|
flock = struct.pack('lxxxxlxxxxlhh', \
|
|
l_start, l_len, os.getpid(), l_type, l_whence)
|
|
elif sys.platform in ['aix3', 'aix4']:
|
|
flock = struct.pack('hhlllii', \
|
|
l_type, l_whence, l_start, l_len, 0, 0, 0)
|
|
else:
|
|
flock = struct.pack('hhllhh', \
|
|
l_type, l_whence, l_start, l_len, 0, 0)
|
|
|
|
flock = fcntl.fcntl(self._file_.fileno(), cmd, flock)
|
|
|
|
if '?' in how:
|
|
if sys.platform in ('netbsd1',
|
|
'openbsd2',
|
|
'freebsd2', 'freebsd3', 'freebsd4', 'freebsd5',
|
|
'bsdos2', 'bsdos3', 'bsdos4'):
|
|
l_start, l_len, l_pid, l_type, l_whence = \
|
|
struct.unpack('lxxxxlxxxxlhh', flock)
|
|
elif sys.platform in ['aix3', 'aix4']:
|
|
l_type, l_whence, l_start, l_len, l_sysid, l_pid, l_vfs = \
|
|
struct.unpack('hhlllii', flock)
|
|
elif sys.platform == "linux2":
|
|
l_type, l_whence, l_start, l_len, l_pid, l_sysid = \
|
|
struct.unpack('hhllhh', flock)
|
|
else:
|
|
l_type, l_whence, l_start, l_len, l_sysid, l_pid = \
|
|
struct.unpack('hhllhh', flock)
|
|
|
|
if l_type != fcntl.F_UNLCK:
|
|
if l_type == fcntl.F_RDLCK:
|
|
return 'r', l_len, l_start, l_whence, l_pid
|
|
else:
|
|
return 'w', l_len, l_start, l_whence, l_pid
|
|
|
|
def open(name, mode='r', bufsize=-1):
|
|
"""Public routine to open a file as a posixfile object."""
|
|
return _posixfile_().open(name, mode, bufsize)
|
|
|
|
def fileopen(file):
|
|
"""Public routine to get a posixfile object from a Python file object."""
|
|
return _posixfile_().fileopen(file)
|
|
|
|
#
|
|
# Constants
|
|
#
|
|
SEEK_SET = 0
|
|
SEEK_CUR = 1
|
|
SEEK_END = 2
|
|
|
|
#
|
|
# End of posixfile.py
|
|
#
|