"""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 | |
""" | |
import warnings | |
warnings.warn("The posixfile module is deprecated; " | |
"fcntl.lockf() provides better locking", DeprecationWarning, 2) | |
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 repr(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', | |
'freebsd6', 'freebsd7', 'freebsd8', | |
'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 | |
# |