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1 /*[clinic input]
2 preserve
3 [clinic start generated code]*/
4 
5 PyDoc_STRVAR(_io_open__doc__,
6 "open($module, /, file, mode=\'r\', buffering=-1, encoding=None,\n"
7 "     errors=None, newline=None, closefd=True, opener=None)\n"
8 "--\n"
9 "\n"
10 "Open file and return a stream.  Raise OSError upon failure.\n"
11 "\n"
12 "file is either a text or byte string giving the name (and the path\n"
13 "if the file isn\'t in the current working directory) of the file to\n"
14 "be opened or an integer file descriptor of the file to be\n"
15 "wrapped. (If a file descriptor is given, it is closed when the\n"
16 "returned I/O object is closed, unless closefd is set to False.)\n"
17 "\n"
18 "mode is an optional string that specifies the mode in which the file\n"
19 "is opened. It defaults to \'r\' which means open for reading in text\n"
20 "mode.  Other common values are \'w\' for writing (truncating the file if\n"
21 "it already exists), \'x\' for creating and writing to a new file, and\n"
22 "\'a\' for appending (which on some Unix systems, means that all writes\n"
23 "append to the end of the file regardless of the current seek position).\n"
24 "In text mode, if encoding is not specified the encoding used is platform\n"
25 "dependent: locale.getpreferredencoding(False) is called to get the\n"
26 "current locale encoding. (For reading and writing raw bytes use binary\n"
27 "mode and leave encoding unspecified.) The available modes are:\n"
28 "\n"
29 "========= ===============================================================\n"
30 "Character Meaning\n"
31 "--------- ---------------------------------------------------------------\n"
32 "\'r\'       open for reading (default)\n"
33 "\'w\'       open for writing, truncating the file first\n"
34 "\'x\'       create a new file and open it for writing\n"
35 "\'a\'       open for writing, appending to the end of the file if it exists\n"
36 "\'b\'       binary mode\n"
37 "\'t\'       text mode (default)\n"
38 "\'+\'       open a disk file for updating (reading and writing)\n"
39 "\'U\'       universal newline mode (deprecated)\n"
40 "========= ===============================================================\n"
41 "\n"
42 "The default mode is \'rt\' (open for reading text). For binary random\n"
43 "access, the mode \'w+b\' opens and truncates the file to 0 bytes, while\n"
44 "\'r+b\' opens the file without truncation. The \'x\' mode implies \'w\' and\n"
45 "raises an `FileExistsError` if the file already exists.\n"
46 "\n"
47 "Python distinguishes between files opened in binary and text modes,\n"
48 "even when the underlying operating system doesn\'t. Files opened in\n"
49 "binary mode (appending \'b\' to the mode argument) return contents as\n"
50 "bytes objects without any decoding. In text mode (the default, or when\n"
51 "\'t\' is appended to the mode argument), the contents of the file are\n"
52 "returned as strings, the bytes having been first decoded using a\n"
53 "platform-dependent encoding or using the specified encoding if given.\n"
54 "\n"
55 "\'U\' mode is deprecated and will raise an exception in future versions\n"
56 "of Python.  It has no effect in Python 3.  Use newline to control\n"
57 "universal newlines mode.\n"
58 "\n"
59 "buffering is an optional integer used to set the buffering policy.\n"
60 "Pass 0 to switch buffering off (only allowed in binary mode), 1 to select\n"
61 "line buffering (only usable in text mode), and an integer > 1 to indicate\n"
62 "the size of a fixed-size chunk buffer.  When no buffering argument is\n"
63 "given, the default buffering policy works as follows:\n"
64 "\n"
65 "* Binary files are buffered in fixed-size chunks; the size of the buffer\n"
66 "  is chosen using a heuristic trying to determine the underlying device\'s\n"
67 "  \"block size\" and falling back on `io.DEFAULT_BUFFER_SIZE`.\n"
68 "  On many systems, the buffer will typically be 4096 or 8192 bytes long.\n"
69 "\n"
70 "* \"Interactive\" text files (files for which isatty() returns True)\n"
71 "  use line buffering.  Other text files use the policy described above\n"
72 "  for binary files.\n"
73 "\n"
74 "encoding is the name of the encoding used to decode or encode the\n"
75 "file. This should only be used in text mode. The default encoding is\n"
76 "platform dependent, but any encoding supported by Python can be\n"
77 "passed.  See the codecs module for the list of supported encodings.\n"
78 "\n"
79 "errors is an optional string that specifies how encoding errors are to\n"
80 "be handled---this argument should not be used in binary mode. Pass\n"
81 "\'strict\' to raise a ValueError exception if there is an encoding error\n"
82 "(the default of None has the same effect), or pass \'ignore\' to ignore\n"
83 "errors. (Note that ignoring encoding errors can lead to data loss.)\n"
84 "See the documentation for codecs.register or run \'help(codecs.Codec)\'\n"
85 "for a list of the permitted encoding error strings.\n"
86 "\n"
87 "newline controls how universal newlines works (it only applies to text\n"
88 "mode). It can be None, \'\', \'\\n\', \'\\r\', and \'\\r\\n\'.  It works as\n"
89 "follows:\n"
90 "\n"
91 "* On input, if newline is None, universal newlines mode is\n"
92 "  enabled. Lines in the input can end in \'\\n\', \'\\r\', or \'\\r\\n\', and\n"
93 "  these are translated into \'\\n\' before being returned to the\n"
94 "  caller. If it is \'\', universal newline mode is enabled, but line\n"
95 "  endings are returned to the caller untranslated. If it has any of\n"
96 "  the other legal values, input lines are only terminated by the given\n"
97 "  string, and the line ending is returned to the caller untranslated.\n"
98 "\n"
99 "* On output, if newline is None, any \'\\n\' characters written are\n"
100 "  translated to the system default line separator, os.linesep. If\n"
101 "  newline is \'\' or \'\\n\', no translation takes place. If newline is any\n"
102 "  of the other legal values, any \'\\n\' characters written are translated\n"
103 "  to the given string.\n"
104 "\n"
105 "If closefd is False, the underlying file descriptor will be kept open\n"
106 "when the file is closed. This does not work when a file name is given\n"
107 "and must be True in that case.\n"
108 "\n"
109 "A custom opener can be used by passing a callable as *opener*. The\n"
110 "underlying file descriptor for the file object is then obtained by\n"
111 "calling *opener* with (*file*, *flags*). *opener* must return an open\n"
112 "file descriptor (passing os.open as *opener* results in functionality\n"
113 "similar to passing None).\n"
114 "\n"
115 "open() returns a file object whose type depends on the mode, and\n"
116 "through which the standard file operations such as reading and writing\n"
117 "are performed. When open() is used to open a file in a text mode (\'w\',\n"
118 "\'r\', \'wt\', \'rt\', etc.), it returns a TextIOWrapper. When used to open\n"
119 "a file in a binary mode, the returned class varies: in read binary\n"
120 "mode, it returns a BufferedReader; in write binary and append binary\n"
121 "modes, it returns a BufferedWriter, and in read/write mode, it returns\n"
122 "a BufferedRandom.\n"
123 "\n"
124 "It is also possible to use a string or bytearray as a file for both\n"
125 "reading and writing. For strings StringIO can be used like a file\n"
126 "opened in a text mode, and for bytes a BytesIO can be used like a file\n"
127 "opened in a binary mode.");
128 
129 #define _IO_OPEN_METHODDEF    \
130     {"open", (PyCFunction)(void(*)(void))_io_open, METH_FASTCALL|METH_KEYWORDS, _io_open__doc__},
131 
132 static PyObject *
133 _io_open_impl(PyObject *module, PyObject *file, const char *mode,
134               int buffering, const char *encoding, const char *errors,
135               const char *newline, int closefd, PyObject *opener);
136 
137 static PyObject *
_io_open(PyObject * module,PyObject * const * args,Py_ssize_t nargs,PyObject * kwnames)138 _io_open(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObject *kwnames)
139 {
140     PyObject *return_value = NULL;
141     static const char * const _keywords[] = {"file", "mode", "buffering", "encoding", "errors", "newline", "closefd", "opener", NULL};
142     static _PyArg_Parser _parser = {NULL, _keywords, "open", 0};
143     PyObject *argsbuf[8];
144     Py_ssize_t noptargs = nargs + (kwnames ? PyTuple_GET_SIZE(kwnames) : 0) - 1;
145     PyObject *file;
146     const char *mode = "r";
147     int buffering = -1;
148     const char *encoding = NULL;
149     const char *errors = NULL;
150     const char *newline = NULL;
151     int closefd = 1;
152     PyObject *opener = Py_None;
153 
154     args = _PyArg_UnpackKeywords(args, nargs, NULL, kwnames, &_parser, 1, 8, 0, argsbuf);
155     if (!args) {
156         goto exit;
157     }
158     file = args[0];
159     if (!noptargs) {
160         goto skip_optional_pos;
161     }
162     if (args[1]) {
163         if (!PyUnicode_Check(args[1])) {
164             _PyArg_BadArgument("open", "argument 'mode'", "str", args[1]);
165             goto exit;
166         }
167         Py_ssize_t mode_length;
168         mode = PyUnicode_AsUTF8AndSize(args[1], &mode_length);
169         if (mode == NULL) {
170             goto exit;
171         }
172         if (strlen(mode) != (size_t)mode_length) {
173             PyErr_SetString(PyExc_ValueError, "embedded null character");
174             goto exit;
175         }
176         if (!--noptargs) {
177             goto skip_optional_pos;
178         }
179     }
180     if (args[2]) {
181         buffering = _PyLong_AsInt(args[2]);
182         if (buffering == -1 && PyErr_Occurred()) {
183             goto exit;
184         }
185         if (!--noptargs) {
186             goto skip_optional_pos;
187         }
188     }
189     if (args[3]) {
190         if (args[3] == Py_None) {
191             encoding = NULL;
192         }
193         else if (PyUnicode_Check(args[3])) {
194             Py_ssize_t encoding_length;
195             encoding = PyUnicode_AsUTF8AndSize(args[3], &encoding_length);
196             if (encoding == NULL) {
197                 goto exit;
198             }
199             if (strlen(encoding) != (size_t)encoding_length) {
200                 PyErr_SetString(PyExc_ValueError, "embedded null character");
201                 goto exit;
202             }
203         }
204         else {
205             _PyArg_BadArgument("open", "argument 'encoding'", "str or None", args[3]);
206             goto exit;
207         }
208         if (!--noptargs) {
209             goto skip_optional_pos;
210         }
211     }
212     if (args[4]) {
213         if (args[4] == Py_None) {
214             errors = NULL;
215         }
216         else if (PyUnicode_Check(args[4])) {
217             Py_ssize_t errors_length;
218             errors = PyUnicode_AsUTF8AndSize(args[4], &errors_length);
219             if (errors == NULL) {
220                 goto exit;
221             }
222             if (strlen(errors) != (size_t)errors_length) {
223                 PyErr_SetString(PyExc_ValueError, "embedded null character");
224                 goto exit;
225             }
226         }
227         else {
228             _PyArg_BadArgument("open", "argument 'errors'", "str or None", args[4]);
229             goto exit;
230         }
231         if (!--noptargs) {
232             goto skip_optional_pos;
233         }
234     }
235     if (args[5]) {
236         if (args[5] == Py_None) {
237             newline = NULL;
238         }
239         else if (PyUnicode_Check(args[5])) {
240             Py_ssize_t newline_length;
241             newline = PyUnicode_AsUTF8AndSize(args[5], &newline_length);
242             if (newline == NULL) {
243                 goto exit;
244             }
245             if (strlen(newline) != (size_t)newline_length) {
246                 PyErr_SetString(PyExc_ValueError, "embedded null character");
247                 goto exit;
248             }
249         }
250         else {
251             _PyArg_BadArgument("open", "argument 'newline'", "str or None", args[5]);
252             goto exit;
253         }
254         if (!--noptargs) {
255             goto skip_optional_pos;
256         }
257     }
258     if (args[6]) {
259         closefd = _PyLong_AsInt(args[6]);
260         if (closefd == -1 && PyErr_Occurred()) {
261             goto exit;
262         }
263         if (!--noptargs) {
264             goto skip_optional_pos;
265         }
266     }
267     opener = args[7];
268 skip_optional_pos:
269     return_value = _io_open_impl(module, file, mode, buffering, encoding, errors, newline, closefd, opener);
270 
271 exit:
272     return return_value;
273 }
274 
275 PyDoc_STRVAR(_io_text_encoding__doc__,
276 "text_encoding($module, encoding, stacklevel=2, /)\n"
277 "--\n"
278 "\n"
279 "A helper function to choose the text encoding.\n"
280 "\n"
281 "When encoding is not None, just return it.\n"
282 "Otherwise, return the default text encoding (i.e. \"locale\").\n"
283 "\n"
284 "This function emits an EncodingWarning if encoding is None and\n"
285 "sys.flags.warn_default_encoding is true.\n"
286 "\n"
287 "This can be used in APIs with an encoding=None parameter.\n"
288 "However, please consider using encoding=\"utf-8\" for new APIs.");
289 
290 #define _IO_TEXT_ENCODING_METHODDEF    \
291     {"text_encoding", (PyCFunction)(void(*)(void))_io_text_encoding, METH_FASTCALL, _io_text_encoding__doc__},
292 
293 static PyObject *
294 _io_text_encoding_impl(PyObject *module, PyObject *encoding, int stacklevel);
295 
296 static PyObject *
_io_text_encoding(PyObject * module,PyObject * const * args,Py_ssize_t nargs)297 _io_text_encoding(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
298 {
299     PyObject *return_value = NULL;
300     PyObject *encoding;
301     int stacklevel = 2;
302 
303     if (!_PyArg_CheckPositional("text_encoding", nargs, 1, 2)) {
304         goto exit;
305     }
306     encoding = args[0];
307     if (nargs < 2) {
308         goto skip_optional;
309     }
310     stacklevel = _PyLong_AsInt(args[1]);
311     if (stacklevel == -1 && PyErr_Occurred()) {
312         goto exit;
313     }
314 skip_optional:
315     return_value = _io_text_encoding_impl(module, encoding, stacklevel);
316 
317 exit:
318     return return_value;
319 }
320 
321 PyDoc_STRVAR(_io_open_code__doc__,
322 "open_code($module, /, path)\n"
323 "--\n"
324 "\n"
325 "Opens the provided file with the intent to import the contents.\n"
326 "\n"
327 "This may perform extra validation beyond open(), but is otherwise interchangeable\n"
328 "with calling open(path, \'rb\').");
329 
330 #define _IO_OPEN_CODE_METHODDEF    \
331     {"open_code", (PyCFunction)(void(*)(void))_io_open_code, METH_FASTCALL|METH_KEYWORDS, _io_open_code__doc__},
332 
333 static PyObject *
334 _io_open_code_impl(PyObject *module, PyObject *path);
335 
336 static PyObject *
_io_open_code(PyObject * module,PyObject * const * args,Py_ssize_t nargs,PyObject * kwnames)337 _io_open_code(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObject *kwnames)
338 {
339     PyObject *return_value = NULL;
340     static const char * const _keywords[] = {"path", NULL};
341     static _PyArg_Parser _parser = {NULL, _keywords, "open_code", 0};
342     PyObject *argsbuf[1];
343     PyObject *path;
344 
345     args = _PyArg_UnpackKeywords(args, nargs, NULL, kwnames, &_parser, 1, 1, 0, argsbuf);
346     if (!args) {
347         goto exit;
348     }
349     if (!PyUnicode_Check(args[0])) {
350         _PyArg_BadArgument("open_code", "argument 'path'", "str", args[0]);
351         goto exit;
352     }
353     if (PyUnicode_READY(args[0]) == -1) {
354         goto exit;
355     }
356     path = args[0];
357     return_value = _io_open_code_impl(module, path);
358 
359 exit:
360     return return_value;
361 }
362 /*[clinic end generated code: output=06e055d1d80b835d input=a9049054013a1b77]*/
363