233 lines
7.5 KiB
Python
Executable File
233 lines
7.5 KiB
Python
Executable File
"""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:])
|
|
|
|
def __del__(self):
|
|
self._file_.close()
|
|
|
|
#
|
|
# Initialization routines
|
|
#
|
|
def open(self, name, mode='r', bufsize=-1):
|
|
import __builtin__
|
|
return self.fileopen(__builtin__.open(name, mode, bufsize))
|
|
|
|
def fileopen(self, file):
|
|
if `type(file)` != "<type 'file'>":
|
|
raise TypeError, 'posixfile.fileopen() arg must be file object'
|
|
self._file_ = file
|
|
# Copy basic file methods
|
|
for method in file.__methods__:
|
|
setattr(self, method, getattr(file, method))
|
|
return self
|
|
|
|
#
|
|
# New methods
|
|
#
|
|
def file(self):
|
|
return self._file_
|
|
|
|
def dup(self):
|
|
import posix
|
|
|
|
try: ignore = posix.fdopen
|
|
except: raise AttributeError, 'dup() method unavailable'
|
|
|
|
return posix.fdopen(posix.dup(self._file_.fileno()), self._file_.mode)
|
|
|
|
def dup2(self, fd):
|
|
import posix
|
|
|
|
try: ignore = posix.fdopen
|
|
except: raise AttributeError, 'dup() method unavailable'
|
|
|
|
posix.dup2(self._file_.fileno(), fd)
|
|
return posix.fdopen(fd, self._file_.mode)
|
|
|
|
def flags(self, *which):
|
|
import fcntl, FCNTL
|
|
|
|
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 | FCNTL.O_NDELAY
|
|
if 'a' in which: l_flags = l_flags | FCNTL.O_APPEND
|
|
if 's' in which: l_flags = l_flags | FCNTL.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 FCNTL.O_APPEND & l_flags: which = which + 'a'
|
|
if fcntl.fcntl(file.fileno(), FCNTL.F_GETFD, 0) & 1:
|
|
which = which + 'c'
|
|
if FCNTL.O_NDELAY & l_flags: which = which + 'n'
|
|
if FCNTL.O_SYNC & l_flags: which = which + 's'
|
|
return which
|
|
|
|
def lock(self, how, *args):
|
|
import struct, fcntl, 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',
|
|
'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',
|
|
'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
|
|
#
|