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Diffstat (limited to 'lib/python2.7/posixfile.py')
| -rw-r--r-- | lib/python2.7/posixfile.py | 237 |
1 files changed, 237 insertions, 0 deletions
diff --git a/lib/python2.7/posixfile.py b/lib/python2.7/posixfile.py new file mode 100644 index 0000000..ff29107 --- /dev/null +++ b/lib/python2.7/posixfile.py @@ -0,0 +1,237 @@ +"""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 +# |