Commit | Line | Data |
---|---|---|
920dae64 AT |
1 | """Extended file operations available in POSIX. |
2 | ||
3 | f = posixfile.open(filename, [mode, [bufsize]]) | |
4 | will create a new posixfile object | |
5 | ||
6 | f = posixfile.fileopen(fileobject) | |
7 | will create a posixfile object from a builtin file object | |
8 | ||
9 | f.file() | |
10 | will return the original builtin file object | |
11 | ||
12 | f.dup() | |
13 | will return a new file object based on a new filedescriptor | |
14 | ||
15 | f.dup2(fd) | |
16 | will return a new file object based on the given filedescriptor | |
17 | ||
18 | f.flags(mode) | |
19 | will turn on the associated flag (merge) | |
20 | mode can contain the following characters: | |
21 | ||
22 | (character representing a flag) | |
23 | a append only flag | |
24 | c close on exec flag | |
25 | n no delay flag | |
26 | s synchronization flag | |
27 | (modifiers) | |
28 | ! turn flags 'off' instead of default 'on' | |
29 | = copy flags 'as is' instead of default 'merge' | |
30 | ? return a string in which the characters represent the flags | |
31 | that are set | |
32 | ||
33 | note: - the '!' and '=' modifiers are mutually exclusive. | |
34 | - the '?' modifier will return the status of the flags after they | |
35 | have been changed by other characters in the mode string | |
36 | ||
37 | f.lock(mode [, len [, start [, whence]]]) | |
38 | will (un)lock a region | |
39 | mode can contain the following characters: | |
40 | ||
41 | (character representing type of lock) | |
42 | u unlock | |
43 | r read lock | |
44 | w write lock | |
45 | (modifiers) | |
46 | | wait until the lock can be granted | |
47 | ? return the first lock conflicting with the requested lock | |
48 | or 'None' if there is no conflict. The lock returned is in the | |
49 | format (mode, len, start, whence, pid) where mode is a | |
50 | character representing the type of lock ('r' or 'w') | |
51 | ||
52 | note: - the '?' modifier prevents a region from being locked; it is | |
53 | query only | |
54 | """ | |
55 | ||
56 | import warnings | |
57 | warnings.warn( | |
58 | "The posixfile module is obsolete and will disappear in the future", | |
59 | DeprecationWarning) | |
60 | del warnings | |
61 | ||
62 | ||
63 | class _posixfile_: | |
64 | """File wrapper class that provides extra POSIX file routines.""" | |
65 | ||
66 | states = ['open', 'closed'] | |
67 | ||
68 | # | |
69 | # Internal routines | |
70 | # | |
71 | def __repr__(self): | |
72 | file = self._file_ | |
73 | return "<%s posixfile '%s', mode '%s' at %s>" % \ | |
74 | (self.states[file.closed], file.name, file.mode, \ | |
75 | hex(id(self))[2:]) | |
76 | ||
77 | # | |
78 | # Initialization routines | |
79 | # | |
80 | def open(self, name, mode='r', bufsize=-1): | |
81 | import __builtin__ | |
82 | return self.fileopen(__builtin__.open(name, mode, bufsize)) | |
83 | ||
84 | def fileopen(self, file): | |
85 | import types | |
86 | if repr(type(file)) != "<type 'file'>": | |
87 | raise TypeError, 'posixfile.fileopen() arg must be file object' | |
88 | self._file_ = file | |
89 | # Copy basic file methods | |
90 | for maybemethod in dir(file): | |
91 | if not maybemethod.startswith('_'): | |
92 | attr = getattr(file, maybemethod) | |
93 | if isinstance(attr, types.BuiltinMethodType): | |
94 | setattr(self, maybemethod, attr) | |
95 | return self | |
96 | ||
97 | # | |
98 | # New methods | |
99 | # | |
100 | def file(self): | |
101 | return self._file_ | |
102 | ||
103 | def dup(self): | |
104 | import posix | |
105 | ||
106 | if not hasattr(posix, 'fdopen'): | |
107 | raise AttributeError, 'dup() method unavailable' | |
108 | ||
109 | return posix.fdopen(posix.dup(self._file_.fileno()), self._file_.mode) | |
110 | ||
111 | def dup2(self, fd): | |
112 | import posix | |
113 | ||
114 | if not hasattr(posix, 'fdopen'): | |
115 | raise AttributeError, 'dup() method unavailable' | |
116 | ||
117 | posix.dup2(self._file_.fileno(), fd) | |
118 | return posix.fdopen(fd, self._file_.mode) | |
119 | ||
120 | def flags(self, *which): | |
121 | import fcntl, os | |
122 | ||
123 | if which: | |
124 | if len(which) > 1: | |
125 | raise TypeError, 'Too many arguments' | |
126 | which = which[0] | |
127 | else: which = '?' | |
128 | ||
129 | l_flags = 0 | |
130 | if 'n' in which: l_flags = l_flags | os.O_NDELAY | |
131 | if 'a' in which: l_flags = l_flags | os.O_APPEND | |
132 | if 's' in which: l_flags = l_flags | os.O_SYNC | |
133 | ||
134 | file = self._file_ | |
135 | ||
136 | if '=' not in which: | |
137 | cur_fl = fcntl.fcntl(file.fileno(), fcntl.F_GETFL, 0) | |
138 | if '!' in which: l_flags = cur_fl & ~ l_flags | |
139 | else: l_flags = cur_fl | l_flags | |
140 | ||
141 | l_flags = fcntl.fcntl(file.fileno(), fcntl.F_SETFL, l_flags) | |
142 | ||
143 | if 'c' in which: | |
144 | arg = ('!' not in which) # 0 is don't, 1 is do close on exec | |
145 | l_flags = fcntl.fcntl(file.fileno(), fcntl.F_SETFD, arg) | |
146 | ||
147 | if '?' in which: | |
148 | which = '' # Return current flags | |
149 | l_flags = fcntl.fcntl(file.fileno(), fcntl.F_GETFL, 0) | |
150 | if os.O_APPEND & l_flags: which = which + 'a' | |
151 | if fcntl.fcntl(file.fileno(), fcntl.F_GETFD, 0) & 1: | |
152 | which = which + 'c' | |
153 | if os.O_NDELAY & l_flags: which = which + 'n' | |
154 | if os.O_SYNC & l_flags: which = which + 's' | |
155 | return which | |
156 | ||
157 | def lock(self, how, *args): | |
158 | import struct, fcntl | |
159 | ||
160 | if 'w' in how: l_type = fcntl.F_WRLCK | |
161 | elif 'r' in how: l_type = fcntl.F_RDLCK | |
162 | elif 'u' in how: l_type = fcntl.F_UNLCK | |
163 | else: raise TypeError, 'no type of lock specified' | |
164 | ||
165 | if '|' in how: cmd = fcntl.F_SETLKW | |
166 | elif '?' in how: cmd = fcntl.F_GETLK | |
167 | else: cmd = fcntl.F_SETLK | |
168 | ||
169 | l_whence = 0 | |
170 | l_start = 0 | |
171 | l_len = 0 | |
172 | ||
173 | if len(args) == 1: | |
174 | l_len = args[0] | |
175 | elif len(args) == 2: | |
176 | l_len, l_start = args | |
177 | elif len(args) == 3: | |
178 | l_len, l_start, l_whence = args | |
179 | elif len(args) > 3: | |
180 | raise TypeError, 'too many arguments' | |
181 | ||
182 | # Hack by davem@magnet.com to get locking to go on freebsd; | |
183 | # additions for AIX by Vladimir.Marangozov@imag.fr | |
184 | import sys, os | |
185 | if sys.platform in ('netbsd1', | |
186 | 'openbsd2', | |
187 | 'freebsd2', 'freebsd3', 'freebsd4', 'freebsd5', | |
188 | 'freebsd6', 'bsdos2', 'bsdos3', 'bsdos4'): | |
189 | flock = struct.pack('lxxxxlxxxxlhh', \ | |
190 | l_start, l_len, os.getpid(), l_type, l_whence) | |
191 | elif sys.platform in ['aix3', 'aix4']: | |
192 | flock = struct.pack('hhlllii', \ | |
193 | l_type, l_whence, l_start, l_len, 0, 0, 0) | |
194 | else: | |
195 | flock = struct.pack('hhllhh', \ | |
196 | l_type, l_whence, l_start, l_len, 0, 0) | |
197 | ||
198 | flock = fcntl.fcntl(self._file_.fileno(), cmd, flock) | |
199 | ||
200 | if '?' in how: | |
201 | if sys.platform in ('netbsd1', | |
202 | 'openbsd2', | |
203 | 'freebsd2', 'freebsd3', 'freebsd4', 'freebsd5', | |
204 | 'bsdos2', 'bsdos3', 'bsdos4'): | |
205 | l_start, l_len, l_pid, l_type, l_whence = \ | |
206 | struct.unpack('lxxxxlxxxxlhh', flock) | |
207 | elif sys.platform in ['aix3', 'aix4']: | |
208 | l_type, l_whence, l_start, l_len, l_sysid, l_pid, l_vfs = \ | |
209 | struct.unpack('hhlllii', flock) | |
210 | elif sys.platform == "linux2": | |
211 | l_type, l_whence, l_start, l_len, l_pid, l_sysid = \ | |
212 | struct.unpack('hhllhh', flock) | |
213 | else: | |
214 | l_type, l_whence, l_start, l_len, l_sysid, l_pid = \ | |
215 | struct.unpack('hhllhh', flock) | |
216 | ||
217 | if l_type != fcntl.F_UNLCK: | |
218 | if l_type == fcntl.F_RDLCK: | |
219 | return 'r', l_len, l_start, l_whence, l_pid | |
220 | else: | |
221 | return 'w', l_len, l_start, l_whence, l_pid | |
222 | ||
223 | def open(name, mode='r', bufsize=-1): | |
224 | """Public routine to open a file as a posixfile object.""" | |
225 | return _posixfile_().open(name, mode, bufsize) | |
226 | ||
227 | def fileopen(file): | |
228 | """Public routine to get a posixfile object from a Python file object.""" | |
229 | return _posixfile_().fileopen(file) | |
230 | ||
231 | # | |
232 | # Constants | |
233 | # | |
234 | SEEK_SET = 0 | |
235 | SEEK_CUR = 1 | |
236 | SEEK_END = 2 | |
237 | ||
238 | # | |
239 | # End of posixfile.py | |
240 | # |