Modules/_fileio.c

   1 /* Author: Daniel Stutzbach */
   2
   3 #define PY_SSIZE_T_CLEAN
   4 #include "Python.h"
   5 #include <sys/types.h>
   6 #include <sys/stat.h>
   7 #include <fcntl.h>
   8 #include <stddef.h> /* For offsetof */
   9
  10 /*
  11  * Known likely problems:
  12  *
  13  * - Files larger then 2**32-1
  14  * - Files with unicode filenames
  15  * - Passing numbers greater than 2**32-1 when an integer is expected
  16  * - Making it work on Windows and other oddball platforms
  17  *
  18  * To Do:
  19  *
  20  * - autoconfify header file inclusion
  21  */
  22
  23 #ifdef MS_WINDOWS
  24 /* can simulate truncate with Win32 API functions; see file_truncate */
  25 #define HAVE_FTRUNCATE
  26 #define WIN32_LEAN_AND_MEAN
  27 #include <windows.h>
  28 #endif
  29
  30 typedef struct {
  31         PyObject_HEAD
  32         int fd;
  33         unsigned readable : 1;
  34         unsigned writable : 1;
  35         int seekable : 2; /* -1 means unknown */
  36         int closefd : 1;
  37         PyObject *weakreflist;
  38 } PyFileIOObject;
  39
  40 PyTypeObject PyFileIO_Type;
  41
  42 #define PyFileIO_Check(op) (PyObject_TypeCheck((op), &PyFileIO_Type))
  43
  44 /* Returns 0 on success, errno (which is < 0) on failure. */
  45 static int
  46 internal_close(PyFileIOObject *self)
  47 {
  48         int save_errno = 0;
  49         if (self->fd >= 0) {
  50                 int fd = self->fd;
  51                 self->fd = -1;
  52                 Py_BEGIN_ALLOW_THREADS
  53                 if (close(fd) < 0)
  54                         save_errno = errno;
  55                 Py_END_ALLOW_THREADS
  56         }
  57         return save_errno;
  58 }
  59
  60 static PyObject *
  61 fileio_close(PyFileIOObject *self)
  62 {
  63         if (!self->closefd) {
  64                 if (PyErr_WarnEx(PyExc_RuntimeWarning,
  65                                  "Trying to close unclosable fd!", 3) < 0) {
  66                         return NULL;
  67                 }
  68                 Py_RETURN_NONE;
  69         }
  70         errno = internal_close(self);
  71         if (errno < 0) {
  72                 PyErr_SetFromErrno(PyExc_IOError);
  73                 return NULL;
  74         }
  75
  76         Py_RETURN_NONE;
  77 }
  78
  79 static PyObject *
  80 fileio_new(PyTypeObject *type, PyObject *args, PyObject *kews)
  81 {
  82         PyFileIOObject *self;
  83
  84         assert(type != NULL && type->tp_alloc != NULL);
  85
  86         self = (PyFileIOObject *) type->tp_alloc(type, 0);
  87         if (self != NULL) {
  88                 self->fd = -1;
  89                 self->weakreflist = NULL;
  90         }
  91
  92         return (PyObject *) self;
  93 }
  94
  95 /* On Unix, open will succeed for directories.
  96    In Python, there should be no file objects referring to
  97    directories, so we need a check.  */
  98
  99 static int
 100 dircheck(PyFileIOObject* self)
 101 {
 102 #if defined(HAVE_FSTAT) && defined(S_IFDIR) && defined(EISDIR)
 103         struct stat buf;
 104         if (self->fd < 0)
 105                 return 0;
 106         if (fstat(self->fd, &buf) == 0 && S_ISDIR(buf.st_mode)) {
 107                 char *msg = strerror(EISDIR);
 108                 PyObject *exc;
 109                 internal_close(self);
 110
 111                 exc = PyObject_CallFunction(PyExc_IOError, "(is)",
 112                                             EISDIR, msg);
 113                 PyErr_SetObject(PyExc_IOError, exc);
 114                 Py_XDECREF(exc);
 115                 return -1;
 116         }
 117 #endif
 118         return 0;
 119 }
 120
 121
 122 static int
 123 fileio_init(PyObject *oself, PyObject *args, PyObject *kwds)
 124 {
 125         PyFileIOObject *self = (PyFileIOObject *) oself;
 126         static char *kwlist[] = {"file", "mode", "closefd", NULL};
 127         char *name = NULL;
 128         char *mode = "r";
 129         char *s;
 130 #ifdef MS_WINDOWS
 131         Py_UNICODE *widename = NULL;
 132 #endif
 133         int ret = 0;
 134         int rwa = 0, plus = 0, append = 0;
 135         int flags = 0;
 136         int fd = -1;
 137         int closefd = 1;
 138
 139         assert(PyFileIO_Check(oself));
 140         if (self->fd >= 0) {
 141                 /* Have to close the existing file first. */
 142                 if (internal_close(self) < 0)
 143                         return -1;
 144         }
 145
 146         if (PyArg_ParseTupleAndKeywords(args, kwds, "i|si:fileio",
 147                                         kwlist, &fd, &mode, &closefd)) {
 148                 if (fd < 0) {
 149                         PyErr_SetString(PyExc_ValueError,
 150                                         "Negative filedescriptor");
 151                         return -1;
 152                 }
 153         }
 154         else {
 155                 PyErr_Clear();
 156
 157 #ifdef Py_WIN_WIDE_FILENAMES
 158             if (GetVersion() < 0x80000000) {
 159                 /* On NT, so wide API available */
 160                 PyObject *po;
 161                 if (PyArg_ParseTupleAndKeywords(args, kwds, "U|si:fileio",
 162                                                 kwlist, &po, &mode, &closefd)
 163                                                 ) {
 164                         widename = PyUnicode_AS_UNICODE(po);
 165                 } else {
 166                         /* Drop the argument parsing error as narrow
 167                            strings are also valid. */
 168                         PyErr_Clear();
 169                 }
 170             }
 171             if (widename == NULL)
 172 #endif
 173             {
 174                 if (!PyArg_ParseTupleAndKeywords(args, kwds, "et|si:fileio",
 175                                                  kwlist,
 176                                                  Py_FileSystemDefaultEncoding,
 177                                                  &name, &mode, &closefd))
 178                         return -1;
 179             }
 180         }
 181
 182         self->readable = self->writable = 0;
 183         self->seekable = -1;
 184         s = mode;
 185         while (*s) {
 186                 switch (*s++) {
 187                 case 'r':
 188                         if (rwa) {
 189                         bad_mode:
 190                                 PyErr_SetString(PyExc_ValueError,
 191                                                 "Must have exactly one of read/write/append mode");
 192                                 goto error;
 193                         }
 194                         rwa = 1;
 195                         self->readable = 1;
 196                         break;
 197                 case 'w':
 198                         if (rwa)
 199                                 goto bad_mode;
 200                         rwa = 1;
 201                         self->writable = 1;
 202                         flags |= O_CREAT | O_TRUNC;
 203                         break;
 204                 case 'a':
 205                         if (rwa)
 206                                 goto bad_mode;
 207                         rwa = 1;
 208                         self->writable = 1;
 209                         flags |= O_CREAT;
 210                         append = 1;
 211                         break;
 212                 case '+':
 213                         if (plus)
 214                                 goto bad_mode;
 215                         self->readable = self->writable = 1;
 216                         plus = 1;
 217                         break;
 218                 default:
 219                         PyErr_Format(PyExc_ValueError,
 220                                      "invalid mode: %.200s", mode);
 221                         goto error;
 222                 }
 223         }
 224
 225         if (!rwa)
 226                 goto bad_mode;
 227
 228         if (self->readable && self->writable)
 229                 flags |= O_RDWR;
 230         else if (self->readable)
 231                 flags |= O_RDONLY;
 232         else
 233                 flags |= O_WRONLY;
 234
 235 #ifdef O_BINARY
 236         flags |= O_BINARY;
 237 #endif
 238
 239 #ifdef O_APPEND
 240         if (append)
 241                 flags |= O_APPEND;
 242 #endif
 243
 244         if (fd >= 0) {
 245                 self->fd = fd;
 246                 self->closefd = closefd;
 247         }
 248         else {
 249                 self->closefd = 1;
 250                 if (!closefd) {
 251                         PyErr_SetString(PyExc_ValueError,
 252                             "Cannot use closefd=True with file name");
 253                         goto error;
 254                 }
 255
 256                 Py_BEGIN_ALLOW_THREADS
 257                 errno = 0;
 258 #ifdef MS_WINDOWS
 259                 if (widename != NULL)
 260                         self->fd = _wopen(widename, flags, 0666);
 261                 else
 262 #endif
 263                         self->fd = open(name, flags, 0666);
 264                 Py_END_ALLOW_THREADS
 265                 if (self->fd < 0) {
 266 #ifdef MS_WINDOWS
 267                         PyErr_SetFromErrnoWithUnicodeFilename(PyExc_IOError, widename);
 268 #else
 269                         PyErr_SetFromErrnoWithFilename(PyExc_IOError, name);
 270 #endif
 271                         goto error;
 272                 }
 273                 if(dircheck(self) < 0)
 274                         goto error;
 275         }
 276
 277         goto done;
 278
 279  error:
 280         ret = -1;
 281
 282  done:
 283         PyMem_Free(name);
 284         return ret;
 285 }
 286
 287 static void
 288 fileio_dealloc(PyFileIOObject *self)
 289 {
 290         if (self->weakreflist != NULL)
 291                 PyObject_ClearWeakRefs((PyObject *) self);
 292
 293         if (self->fd >= 0 && self->closefd) {
 294                 errno = internal_close(self);
 295                 if (errno < 0) {
 296                         PySys_WriteStderr("close failed: [Errno %d] %s\n",
 297                                           errno, strerror(errno));
 298                 }
 299         }
 300
 301         Py_TYPE(self)->tp_free((PyObject *)self);
 302 }
 303
 304 static PyObject *
 305 err_closed(void)
 306 {
 307         PyErr_SetString(PyExc_ValueError, "I/O operation on closed file");
 308         return NULL;
 309 }
 310
 311 static PyObject *
 312 err_mode(char *action)
 313 {
 314         PyErr_Format(PyExc_ValueError, "File not open for %s", action);
 315         return NULL;
 316 }
 317
 318 static PyObject *
 319 fileio_fileno(PyFileIOObject *self)
 320 {
 321         if (self->fd < 0)
 322                 return err_closed();
 323         return PyInt_FromLong((long) self->fd);
 324 }
 325
 326 static PyObject *
 327 fileio_readable(PyFileIOObject *self)
 328 {
 329         if (self->fd < 0)
 330                 return err_closed();
 331         return PyBool_FromLong((long) self->readable);
 332 }
 333
 334 static PyObject *
 335 fileio_writable(PyFileIOObject *self)
 336 {
 337         if (self->fd < 0)
 338                 return err_closed();
 339         return PyBool_FromLong((long) self->writable);
 340 }
 341
 342 static PyObject *
 343 fileio_seekable(PyFileIOObject *self)
 344 {
 345         if (self->fd < 0)
 346                 return err_closed();
 347         if (self->seekable < 0) {
 348                 int ret;
 349                 Py_BEGIN_ALLOW_THREADS
 350                 ret = lseek(self->fd, 0, SEEK_CUR);
 351                 Py_END_ALLOW_THREADS
 352                 if (ret < 0)
 353                         self->seekable = 0;
 354                 else
 355                         self->seekable = 1;
 356         }
 357         return PyBool_FromLong((long) self->seekable);
 358 }
 359
 360 static PyObject *
 361 fileio_readinto(PyFileIOObject *self, PyObject *args)
 362 {
 363         Py_buffer pbuf;
 364         Py_ssize_t n;
 365
 366         if (self->fd < 0)
 367                 return err_closed();
 368         if (!self->readable)
 369                 return err_mode("reading");
 370
 371         if (!PyArg_ParseTuple(args, "w*", &pbuf))
 372                 return NULL;
 373
 374         Py_BEGIN_ALLOW_THREADS
 375         errno = 0;
 376         n = read(self->fd, pbuf.buf, pbuf.len);
 377         Py_END_ALLOW_THREADS
 378         PyBuffer_Release(&pbuf);
 379         if (n < 0) {
 380                 if (errno == EAGAIN)
 381                         Py_RETURN_NONE;
 382                 PyErr_SetFromErrno(PyExc_IOError);
 383                 return NULL;
 384         }
 385
 386         return PyLong_FromSsize_t(n);
 387 }
 388
 389 #define DEFAULT_BUFFER_SIZE (8*1024)
 390
 391 static PyObject *
 392 fileio_readall(PyFileIOObject *self)
 393 {
 394         PyObject *result;
 395         Py_ssize_t total = 0;
 396         int n;
 397
 398         result = PyString_FromStringAndSize(NULL, DEFAULT_BUFFER_SIZE);
 399         if (result == NULL)
 400                 return NULL;
 401
 402         while (1) {
 403                 Py_ssize_t newsize = total + DEFAULT_BUFFER_SIZE;
 404                 if (PyString_GET_SIZE(result) < newsize) {
 405                         if (_PyString_Resize(&result, newsize) < 0) {
 406                                 if (total == 0) {
 407                                         Py_DECREF(result);
 408                                         return NULL;
 409                                 }
 410                                 PyErr_Clear();
 411                                 break;
 412                         }
 413                 }
 414                 Py_BEGIN_ALLOW_THREADS
 415                 errno = 0;
 416                 n = read(self->fd,
 417                          PyString_AS_STRING(result) + total,
 418                          newsize - total);
 419                 Py_END_ALLOW_THREADS
 420                 if (n == 0)
 421                         break;
 422                 if (n < 0) {
 423                         if (total > 0)
 424                                 break;
 425                         if (errno == EAGAIN) {
 426                                 Py_DECREF(result);
 427                                 Py_RETURN_NONE;
 428                         }
 429                         Py_DECREF(result);
 430                         PyErr_SetFromErrno(PyExc_IOError);
 431                         return NULL;
 432                 }
 433                 total += n;
 434         }
 435
 436         if (PyString_GET_SIZE(result) > total) {
 437                 if (_PyString_Resize(&result, total) < 0) {
 438                         /* This should never happen, but just in case */
 439                         Py_DECREF(result);
 440                         return NULL;
 441                 }
 442         }
 443         return result;
 444 }
 445
 446 static PyObject *
 447 fileio_read(PyFileIOObject *self, PyObject *args)
 448 {
 449         char *ptr;
 450         Py_ssize_t n;
 451         Py_ssize_t size = -1;
 452         PyObject *bytes;
 453
 454         if (self->fd < 0)
 455                 return err_closed();
 456         if (!self->readable)
 457                 return err_mode("reading");
 458
 459         if (!PyArg_ParseTuple(args, "|n", &size))
 460                 return NULL;
 461
 462         if (size < 0) {
 463                 return fileio_readall(self);
 464         }
 465
 466         bytes = PyString_FromStringAndSize(NULL, size);
 467         if (bytes == NULL)
 468                 return NULL;
 469         ptr = PyString_AS_STRING(bytes);
 470
 471         Py_BEGIN_ALLOW_THREADS
 472         errno = 0;
 473         n = read(self->fd, ptr, size);
 474         Py_END_ALLOW_THREADS
 475
 476         if (n < 0) {
 477                 if (errno == EAGAIN)
 478                         Py_RETURN_NONE;
 479                 PyErr_SetFromErrno(PyExc_IOError);
 480                 return NULL;
 481         }
 482
 483         if (n != size) {
 484                 if (_PyString_Resize(&bytes, n) < 0) {
 485                         Py_DECREF(bytes);
 486                         return NULL;
 487                 }
 488         }
 489
 490         return (PyObject *) bytes;
 491 }
 492
 493 static PyObject *
 494 fileio_write(PyFileIOObject *self, PyObject *args)
 495 {
 496         Py_buffer pbuf;
 497         Py_ssize_t n;
 498
 499         if (self->fd < 0)
 500                 return err_closed();
 501         if (!self->writable)
 502                 return err_mode("writing");
 503
 504         if (!PyArg_ParseTuple(args, "s*", &pbuf))
 505                 return NULL;
 506
 507         Py_BEGIN_ALLOW_THREADS
 508         errno = 0;
 509         n = write(self->fd, pbuf.buf, pbuf.len);
 510         Py_END_ALLOW_THREADS
 511
 512         PyBuffer_Release(&pbuf);
 513
 514         if (n < 0) {
 515                 if (errno == EAGAIN)
 516                         Py_RETURN_NONE;
 517                 PyErr_SetFromErrno(PyExc_IOError);
 518                 return NULL;
 519         }
 520
 521         return PyLong_FromSsize_t(n);
 522 }
 523
 524 /* XXX Windows support below is likely incomplete */
 525
 526 #if defined(MS_WIN64) || defined(MS_WINDOWS)
 527 typedef PY_LONG_LONG Py_off_t;
 528 #else
 529 typedef off_t Py_off_t;
 530 #endif
 531
 532 /* Cribbed from posix_lseek() */
 533 static PyObject *
 534 portable_lseek(int fd, PyObject *posobj, int whence)
 535 {
 536         Py_off_t pos, res;
 537
 538 #ifdef SEEK_SET
 539         /* Turn 0, 1, 2 into SEEK_{SET,CUR,END} */
 540         switch (whence) {
 541 #if SEEK_SET != 0
 542         case 0: whence = SEEK_SET; break;
 543 #endif
 544 #if SEEK_CUR != 1
 545         case 1: whence = SEEK_CUR; break;
 546 #endif
 547 #if SEEL_END != 2
 548         case 2: whence = SEEK_END; break;
 549 #endif
 550         }
 551 #endif /* SEEK_SET */
 552
 553         if (posobj == NULL)
 554                 pos = 0;
 555         else {
 556                 if(PyFloat_Check(posobj)) {
 557                         PyErr_SetString(PyExc_TypeError, "an integer is required");
 558                         return NULL;
 559                 }
 560 #if defined(HAVE_LARGEFILE_SUPPORT)
 561                 pos = PyLong_AsLongLong(posobj);
 562 #else
 563                 pos = PyLong_AsLong(posobj);
 564 #endif
 565                 if (PyErr_Occurred())
 566                         return NULL;
 567         }
 568
 569         Py_BEGIN_ALLOW_THREADS
 570 #if defined(MS_WIN64) || defined(MS_WINDOWS)
 571         res = _lseeki64(fd, pos, whence);
 572 #else
 573         res = lseek(fd, pos, whence);
 574 #endif
 575         Py_END_ALLOW_THREADS
 576         if (res < 0)
 577                 return PyErr_SetFromErrno(PyExc_IOError);
 578
 579 #if defined(HAVE_LARGEFILE_SUPPORT)
 580         return PyLong_FromLongLong(res);
 581 #else
 582         return PyLong_FromLong(res);
 583 #endif
 584 }
 585
 586 static PyObject *
 587 fileio_seek(PyFileIOObject *self, PyObject *args)
 588 {
 589         PyObject *posobj;
 590         int whence = 0;
 591
 592         if (self->fd < 0)
 593                 return err_closed();
 594
 595         if (!PyArg_ParseTuple(args, "O|i", &posobj, &whence))
 596                 return NULL;
 597
 598         return portable_lseek(self->fd, posobj, whence);
 599 }
 600
 601 static PyObject *
 602 fileio_tell(PyFileIOObject *self, PyObject *args)
 603 {
 604         if (self->fd < 0)
 605                 return err_closed();
 606
 607         return portable_lseek(self->fd, NULL, 1);
 608 }
 609
 610 #ifdef HAVE_FTRUNCATE
 611 static PyObject *
 612 fileio_truncate(PyFileIOObject *self, PyObject *args)
 613 {
 614         PyObject *posobj = NULL;
 615         Py_off_t pos;
 616         int ret;
 617         int fd;
 618
 619         fd = self->fd;
 620         if (fd < 0)
 621                 return err_closed();
 622         if (!self->writable)
 623                 return err_mode("writing");
 624
 625         if (!PyArg_ParseTuple(args, "|O", &posobj))
 626                 return NULL;
 627
 628         if (posobj == Py_None || posobj == NULL) {
 629                 /* Get the current position. */
 630                 posobj = portable_lseek(fd, NULL, 1);
 631                 if (posobj == NULL)
 632                         return NULL;
 633         }
 634         else {
 635                 /* Move to the position to be truncated. */
 636                 posobj = portable_lseek(fd, posobj, 0);
 637         }
 638
 639 #if defined(HAVE_LARGEFILE_SUPPORT)
 640         pos = PyLong_AsLongLong(posobj);
 641 #else
 642         pos = PyLong_AsLong(posobj);
 643 #endif
 644         if (PyErr_Occurred())
 645                 return NULL;
 646
 647 #ifdef MS_WINDOWS
 648         /* MS _chsize doesn't work if newsize doesn't fit in 32 bits,
 649            so don't even try using it. */
 650         {
 651                 HANDLE hFile;
 652
 653                 /* Truncate.  Note that this may grow the file! */
 654                 Py_BEGIN_ALLOW_THREADS
 655                 errno = 0;
 656                 hFile = (HANDLE)_get_osfhandle(fd);
 657                 ret = hFile == (HANDLE)-1;
 658                 if (ret == 0) {
 659                         ret = SetEndOfFile(hFile) == 0;
 660                         if (ret)
 661                                 errno = EACCES;
 662                 }
 663                 Py_END_ALLOW_THREADS
 664         }
 665 #else
 666         Py_BEGIN_ALLOW_THREADS
 667         errno = 0;
 668         ret = ftruncate(fd, pos);
 669         Py_END_ALLOW_THREADS
 670 #endif /* !MS_WINDOWS */
 671
 672         if (ret != 0) {
 673                 PyErr_SetFromErrno(PyExc_IOError);
 674                 return NULL;
 675         }
 676
 677         return posobj;
 678 }
 679 #endif
 680
 681 static char *
 682 mode_string(PyFileIOObject *self)
 683 {
 684         if (self->readable) {
 685                 if (self->writable)
 686                         return "r+";
 687                 else
 688                         return "r";
 689         }
 690         else
 691                 return "w";
 692 }
 693
 694 static PyObject *
 695 fileio_repr(PyFileIOObject *self)
 696 {
 697         if (self->fd < 0)
 698                 return PyString_FromFormat("_fileio._FileIO(-1)");
 699
 700         return PyString_FromFormat("_fileio._FileIO(%d, '%s')",
 701                                    self->fd, mode_string(self));
 702 }
 703
 704 static PyObject *
 705 fileio_isatty(PyFileIOObject *self)
 706 {
 707         long res;
 708
 709         if (self->fd < 0)
 710                 return err_closed();
 711         Py_BEGIN_ALLOW_THREADS
 712         res = isatty(self->fd);
 713         Py_END_ALLOW_THREADS
 714         return PyBool_FromLong(res);
 715 }
 716
 717
 718 PyDoc_STRVAR(fileio_doc,
 719 "file(name: str[, mode: str]) -> file IO object\n"
 720 "\n"
 721 "Open a file.  The mode can be 'r', 'w' or 'a' for reading (default),\n"
 722 "writing or appending.  The file will be created if it doesn't exist\n"
 723 "when opened for writing or appending; it will be truncated when\n"
 724 "opened for writing.  Add a '+' to the mode to allow simultaneous\n"
 725 "reading and writing.");
 726
 727 PyDoc_STRVAR(read_doc,
 728 "read(size: int) -> bytes.  read at most size bytes, returned as bytes.\n"
 729 "\n"
 730 "Only makes one system call, so less data may be returned than requested\n"
 731 "In non-blocking mode, returns None if no data is available.\n"
 732 "On end-of-file, returns ''.");
 733
 734 PyDoc_STRVAR(readall_doc,
 735 "readall() -> bytes.  read all data from the file, returned as bytes.\n"
 736 "\n"
 737 "In non-blocking mode, returns as much as is immediately available,\n"
 738 "or None if no data is available.  On end-of-file, returns ''.");
 739
 740 PyDoc_STRVAR(write_doc,
 741 "write(b: bytes) -> int.  Write bytes b to file, return number written.\n"
 742 "\n"
 743 "Only makes one system call, so not all of the data may be written.\n"
 744 "The number of bytes actually written is returned.");
 745
 746 PyDoc_STRVAR(fileno_doc,
 747 "fileno() -> int. \"file descriptor\".\n"
 748 "\n"
 749 "This is needed for lower-level file interfaces, such the fcntl module.");
 750
 751 PyDoc_STRVAR(seek_doc,
 752 "seek(offset: int[, whence: int]) -> None.  Move to new file position.\n"
 753 "\n"
 754 "Argument offset is a byte count.  Optional argument whence defaults to\n"
 755 "0 (offset from start of file, offset should be >= 0); other values are 1\n"
 756 "(move relative to current position, positive or negative), and 2 (move\n"
 757 "relative to end of file, usually negative, although many platforms allow\n"
 758 "seeking beyond the end of a file)."
 759 "\n"
 760 "Note that not all file objects are seekable.");
 761
 762 #ifdef HAVE_FTRUNCATE
 763 PyDoc_STRVAR(truncate_doc,
 764 "truncate([size: int]) -> None.  Truncate the file to at most size bytes.\n"
 765 "\n"
 766 "Size defaults to the current file position, as returned by tell()."
 767 "The current file position is changed to the value of size.");
 768 #endif
 769
 770 PyDoc_STRVAR(tell_doc,
 771 "tell() -> int.  Current file position");
 772
 773 PyDoc_STRVAR(readinto_doc,
 774 "readinto() -> Undocumented.  Don't use this; it may go away.");
 775
 776 PyDoc_STRVAR(close_doc,
 777 "close() -> None.  Close the file.\n"
 778 "\n"
 779 "A closed file cannot be used for further I/O operations.  close() may be\n"
 780 "called more than once without error.  Changes the fileno to -1.");
 781
 782 PyDoc_STRVAR(isatty_doc,
 783 "isatty() -> bool.  True if the file is connected to a tty device.");
 784
 785 PyDoc_STRVAR(seekable_doc,
 786 "seekable() -> bool.  True if file supports random-access.");
 787
 788 PyDoc_STRVAR(readable_doc,
 789 "readable() -> bool.  True if file was opened in a read mode.");
 790
 791 PyDoc_STRVAR(writable_doc,
 792 "writable() -> bool.  True if file was opened in a write mode.");
 793
 794 static PyMethodDef fileio_methods[] = {
 795         {"read",     (PyCFunction)fileio_read,     METH_VARARGS, read_doc},
 796         {"readall",  (PyCFunction)fileio_readall,  METH_NOARGS,  readall_doc},
 797         {"readinto", (PyCFunction)fileio_readinto, METH_VARARGS, readinto_doc},
 798         {"write",    (PyCFunction)fileio_write,    METH_VARARGS, write_doc},
 799         {"seek",     (PyCFunction)fileio_seek,     METH_VARARGS, seek_doc},
 800         {"tell",     (PyCFunction)fileio_tell,     METH_VARARGS, tell_doc},
 801 #ifdef HAVE_FTRUNCATE
 802         {"truncate", (PyCFunction)fileio_truncate, METH_VARARGS, truncate_doc},
 803 #endif
 804         {"close",    (PyCFunction)fileio_close,    METH_NOARGS,  close_doc},
 805         {"seekable", (PyCFunction)fileio_seekable, METH_NOARGS,  seekable_doc},
 806         {"readable", (PyCFunction)fileio_readable, METH_NOARGS,  readable_doc},
 807         {"writable", (PyCFunction)fileio_writable, METH_NOARGS,  writable_doc},
 808         {"fileno",   (PyCFunction)fileio_fileno,   METH_NOARGS,  fileno_doc},
 809         {"isatty",   (PyCFunction)fileio_isatty,   METH_NOARGS,  isatty_doc},
 810         {NULL,       NULL}             /* sentinel */
 811 };
 812
 813 /* 'closed' and 'mode' are attributes for backwards compatibility reasons. */
 814
 815 static PyObject *
 816 get_closed(PyFileIOObject *self, void *closure)
 817 {
 818         return PyBool_FromLong((long)(self->fd < 0));
 819 }
 820
 821 static PyObject *
 822 get_mode(PyFileIOObject *self, void *closure)
 823 {
 824         return PyString_FromString(mode_string(self));
 825 }
 826
 827 static PyGetSetDef fileio_getsetlist[] = {
 828         {"closed", (getter)get_closed, NULL, "True if the file is closed"},
 829         {"mode", (getter)get_mode, NULL, "String giving the file mode"},
 830         {0},
 831 };
 832
 833 PyTypeObject PyFileIO_Type = {
 834         PyVarObject_HEAD_INIT(NULL, 0)
 835         "_FileIO",
 836         sizeof(PyFileIOObject),
 837         0,
 838         (destructor)fileio_dealloc,             /* tp_dealloc */
 839         0,                                      /* tp_print */
 840         0,                                      /* tp_getattr */
 841         0,                                      /* tp_setattr */
 842         0,                                      /* tp_compare */
 843         (reprfunc)fileio_repr,                  /* tp_repr */
 844         0,                                      /* tp_as_number */
 845         0,                                      /* tp_as_sequence */
 846         0,                                      /* tp_as_mapping */
 847         0,                                      /* tp_hash */
 848         0,                                      /* tp_call */
 849         0,                                      /* tp_str */
 850         PyObject_GenericGetAttr,                /* tp_getattro */
 851         0,                                      /* tp_setattro */
 852         0,                                      /* tp_as_buffer */
 853         Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /* tp_flags */
 854         fileio_doc,                             /* tp_doc */
 855         0,                                      /* tp_traverse */
 856         0,                                      /* tp_clear */
 857         0,                                      /* tp_richcompare */
 858         offsetof(PyFileIOObject, weakreflist),  /* tp_weaklistoffset */
 859         0,                                      /* tp_iter */
 860         0,                                      /* tp_iternext */
 861         fileio_methods,                         /* tp_methods */
 862         0,                                      /* tp_members */
 863         fileio_getsetlist,                      /* tp_getset */
 864         0,                                      /* tp_base */
 865         0,                                      /* tp_dict */
 866         0,                                      /* tp_descr_get */
 867         0,                                      /* tp_descr_set */
 868         0,                                      /* tp_dictoffset */
 869         fileio_init,                            /* tp_init */
 870         PyType_GenericAlloc,                    /* tp_alloc */
 871         fileio_new,                             /* tp_new */
 872         PyObject_Del,                           /* tp_free */
 873 };
 874
 875 static PyMethodDef module_methods[] = {
 876         {NULL, NULL}
 877 };
 878
 879 PyMODINIT_FUNC
 880 init_fileio(void)
 881 {
 882         PyObject *m;    /* a module object */
 883
 884         m = Py_InitModule3("_fileio", module_methods,
 885                            "Fast implementation of io.FileIO.");
 886         if (m == NULL)
 887                 return;
 888         if (PyType_Ready(&PyFileIO_Type) < 0)
 889                 return;
 890         Py_INCREF(&PyFileIO_Type);
 891         PyModule_AddObject(m, "_FileIO", (PyObject *) &PyFileIO_Type);
 892 }