extmod/vfs_posix_file.c - lite/micropython - Linaro Git Browser

 /*
  * This file is part of the MicroPython project, http://micropython.org/
  *
  * The MIT License (MIT)
  *
  * Copyright (c) 2013-2018 Damien P. George
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */

 #include "py/mphal.h"
 #include "py/mpthread.h"
 #include "py/runtime.h"
 #include "py/stream.h"
 #include "extmod/vfs_posix.h"

 #if MICROPY_VFS_POSIX

 #include <fcntl.h>
 #include <unistd.h>

 #ifdef _WIN32
 #define fsync _commit
 #else
 #include <poll.h>
 #endif

 typedef struct _mp_obj_vfs_posix_file_t {
     mp_obj_base_t base;
     int fd;
 } mp_obj_vfs_posix_file_t;

 #if MICROPY_CPYTHON_COMPAT
 static void check_fd_is_open(const mp_obj_vfs_posix_file_t *o) {
     if (o->fd < 0) {
         mp_raise_ValueError(MP_ERROR_TEXT("I/O operation on closed file"));
     }
 }
 #else
 #define check_fd_is_open(o)
 #endif

 static void vfs_posix_file_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
     (void)kind;
     mp_obj_vfs_posix_file_t *self = MP_OBJ_TO_PTR(self_in);
     mp_printf(print, "<io.%s %d>", mp_obj_get_type_str(self_in), self->fd);
 }

 mp_obj_t mp_vfs_posix_file_open(const mp_obj_type_t *type, mp_obj_t file_in, mp_obj_t mode_in) {
     const char *mode_s = mp_obj_str_get_str(mode_in);

     int mode_rw = 0, mode_x = 0;
     while (*mode_s) {
         switch (*mode_s++) {
             case 'r':
                 mode_rw = O_RDONLY;
                 break;
             case 'w':
                 mode_rw = O_WRONLY;
                 mode_x = O_CREAT | O_TRUNC;
                 break;
             case 'a':
                 mode_rw = O_WRONLY;
                 mode_x = O_CREAT | O_APPEND;
                 break;
             case '+':
                 mode_rw = O_RDWR;
                 break;
             case 'b':
                 type = &mp_type_vfs_posix_fileio;
                 break;
             case 't':
                 type = &mp_type_vfs_posix_textio;
                 break;
         }
     }

     mp_obj_vfs_posix_file_t *o = mp_obj_malloc_with_finaliser(mp_obj_vfs_posix_file_t, type);
     o->fd = -1; // In case open() fails below, initialise this as a "closed" file object.

     mp_obj_t fid = file_in;

     if (mp_obj_is_small_int(fid)) {
         o->fd = MP_OBJ_SMALL_INT_VALUE(fid);
         return MP_OBJ_FROM_PTR(o);
     }

     const char *fname = mp_obj_str_get_str(fid);
     int fd;
     MP_HAL_RETRY_SYSCALL(fd, open(fname, mode_x | mode_rw, 0644), mp_raise_OSError(err));
     o->fd = fd;
     return MP_OBJ_FROM_PTR(o);
 }

 static mp_obj_t vfs_posix_file_fileno(mp_obj_t self_in) {
     mp_obj_vfs_posix_file_t *self = MP_OBJ_TO_PTR(self_in);
     check_fd_is_open(self);
     return MP_OBJ_NEW_SMALL_INT(self->fd);
 }
 static MP_DEFINE_CONST_FUN_OBJ_1(vfs_posix_file_fileno_obj, vfs_posix_file_fileno);

 static mp_uint_t vfs_posix_file_read(mp_obj_t o_in, void *buf, mp_uint_t size, int *errcode) {
     mp_obj_vfs_posix_file_t *o = MP_OBJ_TO_PTR(o_in);
     check_fd_is_open(o);
     ssize_t r;
     MP_HAL_RETRY_SYSCALL(r, read(o->fd, buf, size), {
         *errcode = err;
         return MP_STREAM_ERROR;
     });
     return (mp_uint_t)r;
 }

 static mp_uint_t vfs_posix_file_write(mp_obj_t o_in, const void *buf, mp_uint_t size, int *errcode) {
     mp_obj_vfs_posix_file_t *o = MP_OBJ_TO_PTR(o_in);
     check_fd_is_open(o);
     #if MICROPY_PY_OS_DUPTERM
     if (o->fd <= STDERR_FILENO) {
         mp_hal_stdout_tx_strn(buf, size);
         return size;
     }
     #endif
     ssize_t r;
     MP_HAL_RETRY_SYSCALL(r, write(o->fd, buf, size), {
         *errcode = err;
         return MP_STREAM_ERROR;
     });
     return (mp_uint_t)r;
 }

 static mp_uint_t vfs_posix_file_ioctl(mp_obj_t o_in, mp_uint_t request, uintptr_t arg, int *errcode) {
     mp_obj_vfs_posix_file_t *o = MP_OBJ_TO_PTR(o_in);

     if (request != MP_STREAM_CLOSE) {
         check_fd_is_open(o);
     }

     switch (request) {
         case MP_STREAM_FLUSH: {
             int ret;
             // fsync(stdin/stdout/stderr) may fail with EINVAL (or ENOTSUP on macos or EBADF
             // on windows), because the OS doesn't buffer these except for instance when they
             // are redirected from/to file, but don't propagate that error out.  Because data
             // is not buffered by us, and stdin/out/err.flush() should just be a no-op.
             #if defined(__APPLE__)
             #define VFS_POSIX_STREAM_STDIO_ERR_CATCH (err == EINVAL || err == ENOTSUP)
             #elif defined(_MSC_VER)
             // In debug builds fsync (i.e. _commit on windows) will generate a debug report via _ASSERTE when
             // called with non-redirected stdin/stdout/stderr (i.e. _isatty) handles because FlushFileBuffers,
             // which it calls internally, will fail since console output is not buffered.
             // In release builds it also fails, but merely returns an error which is handled appropriately below.
             // The check for the handle being stdin/stdout/stderr is added explicitly because according to
             // the documentation _isatty is also true for serial ports for instance.
             #ifdef _DEBUG
             if ((o->fd == STDIN_FILENO || o->fd == STDOUT_FILENO || o->fd == STDERR_FILENO) && _isatty(o->fd)) {
                 return 0;
             }
             #endif
             #define VFS_POSIX_STREAM_STDIO_ERR_CATCH (err == EINVAL || err == EBADF)
             #else
             #define VFS_POSIX_STREAM_STDIO_ERR_CATCH (err == EINVAL)
             #endif
             MP_HAL_RETRY_SYSCALL(ret, fsync(o->fd), {
                 if (VFS_POSIX_STREAM_STDIO_ERR_CATCH
                     // Note: comparing fd against the standard FILENOs is technically not correct, for example:
                     // sys.stderr.close() in Python code results in close(STDERR_FILENO) here, but because
                     // open() uses the next available file descriptor, opening an arbitrary file with
                     // fd = open('/some/file') means that fd becomes STDERR_FILENO.
                     && (o->fd == STDIN_FILENO || o->fd == STDOUT_FILENO || o->fd == STDERR_FILENO)) {
                     return 0;
                 }
                 *errcode = err;
                 return MP_STREAM_ERROR;
             });
             return 0;
         }
         case MP_STREAM_SEEK: {
             struct mp_stream_seek_t *s = (struct mp_stream_seek_t *)arg;
             MP_THREAD_GIL_EXIT();
             off_t off = lseek(o->fd, s->offset, s->whence);
             MP_THREAD_GIL_ENTER();
             if (off == (off_t)-1) {
                 *errcode = errno;
                 return MP_STREAM_ERROR;
             }
             s->offset = off;
             return 0;
         }
         case MP_STREAM_CLOSE:
             if (o->fd >= 0) {
                 MP_THREAD_GIL_EXIT();
                 close(o->fd);
                 MP_THREAD_GIL_ENTER();
             }
             o->fd = -1;
             return 0;
         case MP_STREAM_GET_FILENO:
             return o->fd;
         #if MICROPY_PY_SELECT && !MICROPY_PY_SELECT_POSIX_OPTIMISATIONS
         case MP_STREAM_POLL: {
             #ifdef _WIN32
             mp_raise_NotImplementedError(MP_ERROR_TEXT("poll on file not available on win32"));
             #else
             mp_uint_t ret = 0;
             uint8_t pollevents = 0;
             if (arg & MP_STREAM_POLL_RD) {
                 pollevents |= POLLIN;
             }
             if (arg & MP_STREAM_POLL_WR) {
                 pollevents |= POLLOUT;
             }
             struct pollfd pfd = { .fd = o->fd, .events = pollevents };
             if (poll(&pfd, 1, 0) > 0) {
                 if (pfd.revents & POLLIN) {
                     ret |= MP_STREAM_POLL_RD;
                 }
                 if (pfd.revents & POLLOUT) {
                     ret |= MP_STREAM_POLL_WR;
                 }
                 if (pfd.revents & POLLERR) {
                     ret |= MP_STREAM_POLL_ERR;
                 }
                 if (pfd.revents & POLLHUP) {
                     ret |= MP_STREAM_POLL_HUP;
                 }
                 if (pfd.revents & POLLNVAL) {
                     ret |= MP_STREAM_POLL_NVAL;
                 }
             }
             return ret;
             #endif
         }
         #endif
         default:
             *errcode = EINVAL;
             return MP_STREAM_ERROR;
     }
 }

 static const mp_rom_map_elem_t vfs_posix_rawfile_locals_dict_table[] = {
     { MP_ROM_QSTR(MP_QSTR_fileno), MP_ROM_PTR(&vfs_posix_file_fileno_obj) },
     { MP_ROM_QSTR(MP_QSTR_read), MP_ROM_PTR(&mp_stream_read_obj) },
     { MP_ROM_QSTR(MP_QSTR_readinto), MP_ROM_PTR(&mp_stream_readinto_obj) },
     { MP_ROM_QSTR(MP_QSTR_readline), MP_ROM_PTR(&mp_stream_unbuffered_readline_obj) },
     { MP_ROM_QSTR(MP_QSTR_readlines), MP_ROM_PTR(&mp_stream_unbuffered_readlines_obj) },
     { MP_ROM_QSTR(MP_QSTR_write), MP_ROM_PTR(&mp_stream_write_obj) },
     { MP_ROM_QSTR(MP_QSTR_seek), MP_ROM_PTR(&mp_stream_seek_obj) },
     { MP_ROM_QSTR(MP_QSTR_tell), MP_ROM_PTR(&mp_stream_tell_obj) },
     { MP_ROM_QSTR(MP_QSTR_flush), MP_ROM_PTR(&mp_stream_flush_obj) },
     { MP_ROM_QSTR(MP_QSTR_close), MP_ROM_PTR(&mp_stream_close_obj) },
     { MP_ROM_QSTR(MP_QSTR___del__), MP_ROM_PTR(&mp_stream_close_obj) },
     { MP_ROM_QSTR(MP_QSTR___enter__), MP_ROM_PTR(&mp_identity_obj) },
     { MP_ROM_QSTR(MP_QSTR___exit__), MP_ROM_PTR(&mp_stream___exit___obj) },
 };

 static MP_DEFINE_CONST_DICT(vfs_posix_rawfile_locals_dict, vfs_posix_rawfile_locals_dict_table);

 static const mp_stream_p_t vfs_posix_fileio_stream_p = {
     .read = vfs_posix_file_read,
     .write = vfs_posix_file_write,
     .ioctl = vfs_posix_file_ioctl,
 };

 MP_DEFINE_CONST_OBJ_TYPE(
     mp_type_vfs_posix_fileio,
     MP_QSTR_FileIO,
     MP_TYPE_FLAG_ITER_IS_STREAM,
     print, vfs_posix_file_print,
     protocol, &vfs_posix_fileio_stream_p,
     locals_dict, &vfs_posix_rawfile_locals_dict
     );

 static const mp_stream_p_t vfs_posix_textio_stream_p = {
     .read = vfs_posix_file_read,
     .write = vfs_posix_file_write,
     .ioctl = vfs_posix_file_ioctl,
     .is_text = true,
 };

 #if MICROPY_PY_SYS_STDIO_BUFFER

 mp_obj_vfs_posix_file_t mp_sys_stdin_buffer_obj = {{&mp_type_vfs_posix_fileio}, STDIN_FILENO};
 mp_obj_vfs_posix_file_t mp_sys_stdout_buffer_obj = {{&mp_type_vfs_posix_fileio}, STDOUT_FILENO};
 mp_obj_vfs_posix_file_t mp_sys_stderr_buffer_obj = {{&mp_type_vfs_posix_fileio}, STDERR_FILENO};

 // Forward declarations.
 mp_obj_vfs_posix_file_t mp_sys_stdin_obj;
 mp_obj_vfs_posix_file_t mp_sys_stdout_obj;
 mp_obj_vfs_posix_file_t mp_sys_stderr_obj;

 static void vfs_posix_textio_attr(mp_obj_t self_in, qstr attr, mp_obj_t *dest) {
     if (dest[0] != MP_OBJ_NULL) {
         // These objects are read-only.
         return;
     }

     if (attr == MP_QSTR_buffer) {
         // Implement the `buffer` attribute only on std{in,out,err} instances.
         if (MP_OBJ_TO_PTR(self_in) == &mp_sys_stdin_obj) {
             dest[0] = MP_OBJ_FROM_PTR(&mp_sys_stdin_buffer_obj);
             return;
         }
         if (MP_OBJ_TO_PTR(self_in) == &mp_sys_stdout_obj) {
             dest[0] = MP_OBJ_FROM_PTR(&mp_sys_stdout_buffer_obj);
             return;
         }
         if (MP_OBJ_TO_PTR(self_in) == &mp_sys_stderr_obj) {
             dest[0] = MP_OBJ_FROM_PTR(&mp_sys_stderr_buffer_obj);
             return;
         }
     }

     // Any other attribute - forward to locals dict.
     dest[1] = MP_OBJ_SENTINEL;
 };

 #define VFS_POSIX_TEXTIO_TYPE_ATTR attr, vfs_posix_textio_attr,

 #else

 #define VFS_POSIX_TEXTIO_TYPE_ATTR

 #endif // MICROPY_PY_SYS_STDIO_BUFFER

 MP_DEFINE_CONST_OBJ_TYPE(
     mp_type_vfs_posix_textio,
     MP_QSTR_TextIOWrapper,
     MP_TYPE_FLAG_ITER_IS_STREAM,
     print, vfs_posix_file_print,
     protocol, &vfs_posix_textio_stream_p,
     VFS_POSIX_TEXTIO_TYPE_ATTR
     locals_dict, &vfs_posix_rawfile_locals_dict
     );

 mp_obj_vfs_posix_file_t mp_sys_stdin_obj = {{&mp_type_vfs_posix_textio}, STDIN_FILENO};
 mp_obj_vfs_posix_file_t mp_sys_stdout_obj = {{&mp_type_vfs_posix_textio}, STDOUT_FILENO};
 mp_obj_vfs_posix_file_t mp_sys_stderr_obj = {{&mp_type_vfs_posix_textio}, STDERR_FILENO};

 #endif // MICROPY_VFS_POSIX
	/*
	* This file is part of the MicroPython project, http://micropython.org/
	*
	* The MIT License (MIT)
	*
	* Copyright (c) 2013-2018 Damien P. George
	*
	* Permission is hereby granted, free of charge, to any person obtaining a copy
	* of this software and associated documentation files (the "Software"), to deal
	* in the Software without restriction, including without limitation the rights
	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	* copies of the Software, and to permit persons to whom the Software is
	* furnished to do so, subject to the following conditions:
	*
	* The above copyright notice and this permission notice shall be included in
	* all copies or substantial portions of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	* THE SOFTWARE.
	*/

	#include "py/mphal.h"
	#include "py/mpthread.h"
	#include "py/runtime.h"
	#include "py/stream.h"
	#include "extmod/vfs_posix.h"

	#if MICROPY_VFS_POSIX

	#include <fcntl.h>
	#include <unistd.h>

	#ifdef _WIN32
	#define fsync _commit
	#else
	#include <poll.h>
	#endif

	typedef struct _mp_obj_vfs_posix_file_t {
	mp_obj_base_t base;
	int fd;
	} mp_obj_vfs_posix_file_t;

	#if MICROPY_CPYTHON_COMPAT
	static void check_fd_is_open(const mp_obj_vfs_posix_file_t *o) {
	if (o->fd < 0) {
	mp_raise_ValueError(MP_ERROR_TEXT("I/O operation on closed file"));
	}
	}
	#else
	#define check_fd_is_open(o)
	#endif

	static void vfs_posix_file_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
	(void)kind;
	mp_obj_vfs_posix_file_t *self = MP_OBJ_TO_PTR(self_in);
	mp_printf(print, "<io.%s %d>", mp_obj_get_type_str(self_in), self->fd);
	}

	mp_obj_t mp_vfs_posix_file_open(const mp_obj_type_t *type, mp_obj_t file_in, mp_obj_t mode_in) {
	const char *mode_s = mp_obj_str_get_str(mode_in);

	int mode_rw = 0, mode_x = 0;
	while (*mode_s) {
	switch (*mode_s++) {
	case 'r':
	mode_rw = O_RDONLY;
	break;
	case 'w':
	mode_rw = O_WRONLY;
	mode_x = O_CREAT \| O_TRUNC;
	break;
	case 'a':
	mode_rw = O_WRONLY;
	mode_x = O_CREAT \| O_APPEND;
	break;
	case '+':
	mode_rw = O_RDWR;
	break;
	case 'b':
	type = &mp_type_vfs_posix_fileio;
	break;
	case 't':
	type = &mp_type_vfs_posix_textio;
	break;
	}
	}

	mp_obj_vfs_posix_file_t *o = mp_obj_malloc_with_finaliser(mp_obj_vfs_posix_file_t, type);
	o->fd = -1; // In case open() fails below, initialise this as a "closed" file object.

	mp_obj_t fid = file_in;

	if (mp_obj_is_small_int(fid)) {
	o->fd = MP_OBJ_SMALL_INT_VALUE(fid);
	return MP_OBJ_FROM_PTR(o);
	}

	const char *fname = mp_obj_str_get_str(fid);
	int fd;
	MP_HAL_RETRY_SYSCALL(fd, open(fname, mode_x \| mode_rw, 0644), mp_raise_OSError(err));
	o->fd = fd;
	return MP_OBJ_FROM_PTR(o);
	}

	static mp_obj_t vfs_posix_file_fileno(mp_obj_t self_in) {
	mp_obj_vfs_posix_file_t *self = MP_OBJ_TO_PTR(self_in);
	check_fd_is_open(self);
	return MP_OBJ_NEW_SMALL_INT(self->fd);
	}
	static MP_DEFINE_CONST_FUN_OBJ_1(vfs_posix_file_fileno_obj, vfs_posix_file_fileno);

	static mp_uint_t vfs_posix_file_read(mp_obj_t o_in, void buf, mp_uint_t size, int errcode) {
	mp_obj_vfs_posix_file_t *o = MP_OBJ_TO_PTR(o_in);
	check_fd_is_open(o);
	ssize_t r;
	MP_HAL_RETRY_SYSCALL(r, read(o->fd, buf, size), {
	*errcode = err;
	return MP_STREAM_ERROR;
	});
	return (mp_uint_t)r;
	}

	static mp_uint_t vfs_posix_file_write(mp_obj_t o_in, const void buf, mp_uint_t size, int errcode) {
	mp_obj_vfs_posix_file_t *o = MP_OBJ_TO_PTR(o_in);
	check_fd_is_open(o);
	#if MICROPY_PY_OS_DUPTERM
	if (o->fd <= STDERR_FILENO) {
	mp_hal_stdout_tx_strn(buf, size);
	return size;
	}
	#endif
	ssize_t r;
	MP_HAL_RETRY_SYSCALL(r, write(o->fd, buf, size), {
	*errcode = err;
	return MP_STREAM_ERROR;
	});
	return (mp_uint_t)r;
	}

	static mp_uint_t vfs_posix_file_ioctl(mp_obj_t o_in, mp_uint_t request, uintptr_t arg, int *errcode) {
	mp_obj_vfs_posix_file_t *o = MP_OBJ_TO_PTR(o_in);

	if (request != MP_STREAM_CLOSE) {
	check_fd_is_open(o);
	}

	switch (request) {
	case MP_STREAM_FLUSH: {
	int ret;
	// fsync(stdin/stdout/stderr) may fail with EINVAL (or ENOTSUP on macos or EBADF
	// on windows), because the OS doesn't buffer these except for instance when they
	// are redirected from/to file, but don't propagate that error out. Because data
	// is not buffered by us, and stdin/out/err.flush() should just be a no-op.
	#if defined(__APPLE__)
	#define VFS_POSIX_STREAM_STDIO_ERR_CATCH (err == EINVAL \|\| err == ENOTSUP)
	#elif defined(_MSC_VER)
	// In debug builds fsync (i.e. _commit on windows) will generate a debug report via _ASSERTE when
	// called with non-redirected stdin/stdout/stderr (i.e. _isatty) handles because FlushFileBuffers,
	// which it calls internally, will fail since console output is not buffered.
	// In release builds it also fails, but merely returns an error which is handled appropriately below.
	// The check for the handle being stdin/stdout/stderr is added explicitly because according to
	// the documentation _isatty is also true for serial ports for instance.
	#ifdef _DEBUG
	if ((o->fd == STDIN_FILENO \|\| o->fd == STDOUT_FILENO \|\| o->fd == STDERR_FILENO) && _isatty(o->fd)) {
	return 0;
	}
	#endif
	#define VFS_POSIX_STREAM_STDIO_ERR_CATCH (err == EINVAL \|\| err == EBADF)
	#else
	#define VFS_POSIX_STREAM_STDIO_ERR_CATCH (err == EINVAL)
	#endif
	MP_HAL_RETRY_SYSCALL(ret, fsync(o->fd), {
	if (VFS_POSIX_STREAM_STDIO_ERR_CATCH
	// Note: comparing fd against the standard FILENOs is technically not correct, for example:
	// sys.stderr.close() in Python code results in close(STDERR_FILENO) here, but because
	// open() uses the next available file descriptor, opening an arbitrary file with
	// fd = open('/some/file') means that fd becomes STDERR_FILENO.
	&& (o->fd == STDIN_FILENO \|\| o->fd == STDOUT_FILENO \|\| o->fd == STDERR_FILENO)) {
	return 0;
	}
	*errcode = err;
	return MP_STREAM_ERROR;
	});
	return 0;
	}
	case MP_STREAM_SEEK: {
	struct mp_stream_seek_t s = (struct mp_stream_seek_t )arg;
	MP_THREAD_GIL_EXIT();
	off_t off = lseek(o->fd, s->offset, s->whence);
	MP_THREAD_GIL_ENTER();
	if (off == (off_t)-1) {
	*errcode = errno;
	return MP_STREAM_ERROR;
	}
	s->offset = off;
	return 0;
	}
	case MP_STREAM_CLOSE:
	if (o->fd >= 0) {
	MP_THREAD_GIL_EXIT();
	close(o->fd);
	MP_THREAD_GIL_ENTER();
	}
	o->fd = -1;
	return 0;
	case MP_STREAM_GET_FILENO:
	return o->fd;
	#if MICROPY_PY_SELECT && !MICROPY_PY_SELECT_POSIX_OPTIMISATIONS
	case MP_STREAM_POLL: {
	#ifdef _WIN32
	mp_raise_NotImplementedError(MP_ERROR_TEXT("poll on file not available on win32"));
	#else
	mp_uint_t ret = 0;
	uint8_t pollevents = 0;
	if (arg & MP_STREAM_POLL_RD) {
	pollevents \|= POLLIN;
	}
	if (arg & MP_STREAM_POLL_WR) {
	pollevents \|= POLLOUT;
	}
	struct pollfd pfd = { .fd = o->fd, .events = pollevents };
	if (poll(&pfd, 1, 0) > 0) {
	if (pfd.revents & POLLIN) {
	ret \|= MP_STREAM_POLL_RD;
	}
	if (pfd.revents & POLLOUT) {
	ret \|= MP_STREAM_POLL_WR;
	}
	if (pfd.revents & POLLERR) {
	ret \|= MP_STREAM_POLL_ERR;
	}
	if (pfd.revents & POLLHUP) {
	ret \|= MP_STREAM_POLL_HUP;
	}
	if (pfd.revents & POLLNVAL) {
	ret \|= MP_STREAM_POLL_NVAL;
	}
	}
	return ret;
	#endif
	}
	#endif
	default:
	*errcode = EINVAL;
	return MP_STREAM_ERROR;
	}
	}

	static const mp_rom_map_elem_t vfs_posix_rawfile_locals_dict_table[] = {
	{ MP_ROM_QSTR(MP_QSTR_fileno), MP_ROM_PTR(&vfs_posix_file_fileno_obj) },
	{ MP_ROM_QSTR(MP_QSTR_read), MP_ROM_PTR(&mp_stream_read_obj) },
	{ MP_ROM_QSTR(MP_QSTR_readinto), MP_ROM_PTR(&mp_stream_readinto_obj) },
	{ MP_ROM_QSTR(MP_QSTR_readline), MP_ROM_PTR(&mp_stream_unbuffered_readline_obj) },
	{ MP_ROM_QSTR(MP_QSTR_readlines), MP_ROM_PTR(&mp_stream_unbuffered_readlines_obj) },
	{ MP_ROM_QSTR(MP_QSTR_write), MP_ROM_PTR(&mp_stream_write_obj) },
	{ MP_ROM_QSTR(MP_QSTR_seek), MP_ROM_PTR(&mp_stream_seek_obj) },
	{ MP_ROM_QSTR(MP_QSTR_tell), MP_ROM_PTR(&mp_stream_tell_obj) },
	{ MP_ROM_QSTR(MP_QSTR_flush), MP_ROM_PTR(&mp_stream_flush_obj) },
	{ MP_ROM_QSTR(MP_QSTR_close), MP_ROM_PTR(&mp_stream_close_obj) },
	{ MP_ROM_QSTR(MP_QSTR___del__), MP_ROM_PTR(&mp_stream_close_obj) },
	{ MP_ROM_QSTR(MP_QSTR___enter__), MP_ROM_PTR(&mp_identity_obj) },
	{ MP_ROM_QSTR(MP_QSTR___exit__), MP_ROM_PTR(&mp_stream___exit___obj) },
	};

	static MP_DEFINE_CONST_DICT(vfs_posix_rawfile_locals_dict, vfs_posix_rawfile_locals_dict_table);

	static const mp_stream_p_t vfs_posix_fileio_stream_p = {
	.read = vfs_posix_file_read,
	.write = vfs_posix_file_write,
	.ioctl = vfs_posix_file_ioctl,
	};

	MP_DEFINE_CONST_OBJ_TYPE(
	mp_type_vfs_posix_fileio,
	MP_QSTR_FileIO,
	MP_TYPE_FLAG_ITER_IS_STREAM,
	print, vfs_posix_file_print,
	protocol, &vfs_posix_fileio_stream_p,
	locals_dict, &vfs_posix_rawfile_locals_dict
	);

	static const mp_stream_p_t vfs_posix_textio_stream_p = {
	.read = vfs_posix_file_read,
	.write = vfs_posix_file_write,
	.ioctl = vfs_posix_file_ioctl,
	.is_text = true,
	};

	#if MICROPY_PY_SYS_STDIO_BUFFER

	mp_obj_vfs_posix_file_t mp_sys_stdin_buffer_obj = {{&mp_type_vfs_posix_fileio}, STDIN_FILENO};
	mp_obj_vfs_posix_file_t mp_sys_stdout_buffer_obj = {{&mp_type_vfs_posix_fileio}, STDOUT_FILENO};
	mp_obj_vfs_posix_file_t mp_sys_stderr_buffer_obj = {{&mp_type_vfs_posix_fileio}, STDERR_FILENO};

	// Forward declarations.
	mp_obj_vfs_posix_file_t mp_sys_stdin_obj;
	mp_obj_vfs_posix_file_t mp_sys_stdout_obj;
	mp_obj_vfs_posix_file_t mp_sys_stderr_obj;

	static void vfs_posix_textio_attr(mp_obj_t self_in, qstr attr, mp_obj_t *dest) {
	if (dest[0] != MP_OBJ_NULL) {
	// These objects are read-only.
	return;
	}

	if (attr == MP_QSTR_buffer) {
	// Implement the `buffer` attribute only on std{in,out,err} instances.
	if (MP_OBJ_TO_PTR(self_in) == &mp_sys_stdin_obj) {
	dest[0] = MP_OBJ_FROM_PTR(&mp_sys_stdin_buffer_obj);
	return;
	}
	if (MP_OBJ_TO_PTR(self_in) == &mp_sys_stdout_obj) {
	dest[0] = MP_OBJ_FROM_PTR(&mp_sys_stdout_buffer_obj);
	return;
	}
	if (MP_OBJ_TO_PTR(self_in) == &mp_sys_stderr_obj) {
	dest[0] = MP_OBJ_FROM_PTR(&mp_sys_stderr_buffer_obj);
	return;
	}
	}

	// Any other attribute - forward to locals dict.
	dest[1] = MP_OBJ_SENTINEL;
	};

	#define VFS_POSIX_TEXTIO_TYPE_ATTR attr, vfs_posix_textio_attr,

	#else

	#define VFS_POSIX_TEXTIO_TYPE_ATTR

	#endif // MICROPY_PY_SYS_STDIO_BUFFER

	MP_DEFINE_CONST_OBJ_TYPE(
	mp_type_vfs_posix_textio,
	MP_QSTR_TextIOWrapper,
	MP_TYPE_FLAG_ITER_IS_STREAM,
	print, vfs_posix_file_print,
	protocol, &vfs_posix_textio_stream_p,
	VFS_POSIX_TEXTIO_TYPE_ATTR
	locals_dict, &vfs_posix_rawfile_locals_dict
	);

	mp_obj_vfs_posix_file_t mp_sys_stdin_obj = {{&mp_type_vfs_posix_textio}, STDIN_FILENO};
	mp_obj_vfs_posix_file_t mp_sys_stdout_obj = {{&mp_type_vfs_posix_textio}, STDOUT_FILENO};
	mp_obj_vfs_posix_file_t mp_sys_stderr_obj = {{&mp_type_vfs_posix_textio}, STDERR_FILENO};

	#endif // MICROPY_VFS_POSIX