openkylin
/
glib2.0
mirror of https://gitee.com/openkylin/glib2.0.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity
glib2.0/glib/gstdio.c

1958 lines
57 KiB
C
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

/* gstdio.c - wrappers for C library functions
*
* Copyright 2004 Tor Lillqvist
*
* SPDX-License-Identifier: LGPL-2.1-or-later
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "config.h"
#include "glibconfig.h"
/* Don’t redefine (for example) g_open() to open(), since we actually want to
* define g_open() in this file and export it as a symbol. See gstdio.h. */
#define G_STDIO_WRAP_ON_UNIX
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#ifdef G_OS_UNIX
#include <unistd.h>
#endif
#ifdef G_OS_WIN32
#include <windows.h>
#include <errno.h>
#include <wchar.h>
#include <direct.h>
#include <io.h>
#include <sys/utime.h>
#include <stdlib.h> /* for MB_CUR_MAX */
#else
#include <utime.h>
#include <errno.h>
#endif
#include "gstdio.h"
#include "gstdioprivate.h"
#if !defined (G_OS_UNIX) && !defined (G_OS_WIN32)
#error Please port this to your operating system
#endif
#if defined (_MSC_VER) && !defined(_WIN64)
#undef _wstat
#define _wstat _wstat32
#endif
#if defined (G_OS_WIN32)
/* We can't include Windows DDK and Windows SDK simultaneously,
* so let's copy this here from MinGW-w64 DDK.
* The structure is ultimately documented here:
* https://msdn.microsoft.com/en-us/library/ff552012(v=vs.85).aspx
*/
typedef struct _REPARSE_DATA_BUFFER
{
ULONG ReparseTag;
USHORT ReparseDataLength;
USHORT Reserved;
union
{
struct
{
USHORT SubstituteNameOffset;
USHORT SubstituteNameLength;
USHORT PrintNameOffset;
USHORT PrintNameLength;
ULONG Flags;
WCHAR PathBuffer[1];
} SymbolicLinkReparseBuffer;
struct
{
USHORT SubstituteNameOffset;
USHORT SubstituteNameLength;
USHORT PrintNameOffset;
USHORT PrintNameLength;
WCHAR PathBuffer[1];
} MountPointReparseBuffer;
struct
{
UCHAR DataBuffer[1];
} GenericReparseBuffer;
};
} REPARSE_DATA_BUFFER, *PREPARSE_DATA_BUFFER;
static int
w32_error_to_errno (DWORD error_code)
{
switch (error_code)
{
case ERROR_ACCESS_DENIED:
return EACCES;
break;
case ERROR_ALREADY_EXISTS:
case ERROR_FILE_EXISTS:
return EEXIST;
case ERROR_FILE_NOT_FOUND:
return ENOENT;
break;
case ERROR_INVALID_FUNCTION:
return EFAULT;
break;
case ERROR_INVALID_HANDLE:
return EBADF;
break;
case ERROR_INVALID_PARAMETER:
return EINVAL;
break;
case ERROR_LOCK_VIOLATION:
case ERROR_SHARING_VIOLATION:
return EACCES;
break;
case ERROR_NOT_ENOUGH_MEMORY:
case ERROR_OUTOFMEMORY:
return ENOMEM;
break;
case ERROR_NOT_SAME_DEVICE:
return EXDEV;
break;
case ERROR_PATH_NOT_FOUND:
return ENOENT; /* or ELOOP, or ENAMETOOLONG */
break;
default:
return EIO;
break;
}
}
#include "gstdio-private.c"
/* Windows implementation of fopen() does not accept modes such as
* "wb+". The 'b' needs to be appended to "w+", i.e. "w+b". Note
* that otherwise these 2 modes are supposed to be aliases, hence
* swappable at will. TODO: Is this still true?
*/
static void
_g_win32_fix_mode (wchar_t *mode)
{
wchar_t *ptr;
wchar_t temp;
ptr = wcschr (mode, L'+');
if (ptr != NULL && (ptr - mode) > 1)
{
temp = mode[1];
mode[1] = *ptr;
*ptr = temp;
}
}
/* From
* https://support.microsoft.com/en-ca/help/167296/how-to-convert-a-unix-time-t-to-a-win32-filetime-or-systemtime
* FT = UT * 10000000 + 116444736000000000.
* Therefore:
* UT = (FT - 116444736000000000) / 10000000.
* Converts FILETIME to unix epoch time in form
* of a signed 64-bit integer (can be negative).
*
* The function that does the reverse can be found in
* gio/glocalfileinfo.c.
*/
static gint64
_g_win32_filetime_to_unix_time (const FILETIME *ft,
gint32 *nsec)
{
gint64 result;
/* 1 unit of FILETIME is 100ns */
const gint64 hundreds_of_usec_per_sec = 10000000;
/* The difference between January 1, 1601 UTC (FILETIME epoch) and UNIX epoch
* in hundreds of nanoseconds.
*/
const gint64 filetime_unix_epoch_offset = 116444736000000000;
result = ((gint64) ft->dwLowDateTime) | (((gint64) ft->dwHighDateTime) << 32);
result -= filetime_unix_epoch_offset;
if (nsec)
*nsec = (result % hundreds_of_usec_per_sec) * 100;
return result / hundreds_of_usec_per_sec;
}
# ifdef _MSC_VER
# ifndef S_IXUSR
# define _S_IRUSR _S_IREAD
# define _S_IWUSR _S_IWRITE
# define _S_IXUSR _S_IEXEC
# define S_IRUSR _S_IRUSR
# define S_IWUSR _S_IWUSR
# define S_IXUSR _S_IXUSR
# define S_IRGRP (S_IRUSR >> 3)
# define S_IWGRP (S_IWUSR >> 3)
# define S_IXGRP (S_IXUSR >> 3)
# define S_IROTH (S_IRGRP >> 3)
# define S_IWOTH (S_IWGRP >> 3)
# define S_IXOTH (S_IXGRP >> 3)
# endif
# ifndef S_ISDIR
# define S_ISDIR(m) (((m) & _S_IFMT) == _S_IFDIR)
# endif
# endif
/* Uses filename and BHFI to fill a stat64 structure.
* Tries to reproduce the behaviour and quirks of MS C runtime stat().
*/
static int
_g_win32_fill_statbuf_from_handle_info (const wchar_t *filename,
const wchar_t *filename_target,
const BY_HANDLE_FILE_INFORMATION *handle_info,
struct __stat64 *statbuf)
{
wchar_t drive_letter_w = 0;
size_t drive_letter_size = MB_CUR_MAX;
char *drive_letter = _alloca (drive_letter_size);
/* If filename (target or link) is absolute,
* then use the drive letter from it as-is.
*/
if (filename_target != NULL &&
filename_target[0] != L'\0' &&
filename_target[1] == L':')
drive_letter_w = filename_target[0];
else if (filename[0] != L'\0' &&
filename[1] == L':')
drive_letter_w = filename[0];
if (drive_letter_w > 0 &&
iswalpha (drive_letter_w) &&
iswascii (drive_letter_w) &&
wctomb (drive_letter, drive_letter_w) == 1)
statbuf->st_dev = toupper (drive_letter[0]) - 'A'; /* 0 means A: drive */
else
/* Otherwise use the PWD drive.
* Return value of 0 gives us 0 - 1 = -1,
* which is the "no idea" value for st_dev.
*/
statbuf->st_dev = _getdrive () - 1;
statbuf->st_rdev = statbuf->st_dev;
/* Theoretically, it's possible to set it for ext-FS. No idea how.
* Meaningless for all filesystems that Windows normally uses.
*/
statbuf->st_ino = 0;
statbuf->st_mode = 0;
if ((handle_info->dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) == FILE_ATTRIBUTE_DIRECTORY)
statbuf->st_mode |= S_IFDIR | S_IXUSR | S_IXGRP | S_IXOTH;
else
statbuf->st_mode |= S_IFREG;
/* No idea what S_IFCHR means here. */
/* S_IFIFO is not even mentioned in MSDN */
/* S_IFBLK is also not mentioned */
/* The aim here is to reproduce MS stat() behaviour,
* even if it's braindead.
*/
statbuf->st_mode |= S_IRUSR | S_IRGRP | S_IROTH;
if ((handle_info->dwFileAttributes & FILE_ATTRIBUTE_READONLY) != FILE_ATTRIBUTE_READONLY)
statbuf->st_mode |= S_IWUSR | S_IWGRP | S_IWOTH;
if (!S_ISDIR (statbuf->st_mode))
{
const wchar_t *name;
const wchar_t *dot = NULL;
if (filename_target != NULL)
name = filename_target;
else
name = filename;
do
{
wchar_t *last_dot = wcschr (name, L'.');
if (last_dot == NULL)
break;
dot = last_dot;
name = &last_dot[1];
}
while (TRUE);
if ((dot != NULL &&
(wcsicmp (dot, L".exe") == 0 ||
wcsicmp (dot, L".com") == 0 ||
wcsicmp (dot, L".bat") == 0 ||
wcsicmp (dot, L".cmd") == 0)))
statbuf->st_mode |= S_IXUSR | S_IXGRP | S_IXOTH;
}
statbuf->st_nlink = handle_info->nNumberOfLinks;
statbuf->st_uid = statbuf->st_gid = 0;
statbuf->st_size = (((guint64) handle_info->nFileSizeHigh) << 32) | handle_info->nFileSizeLow;
statbuf->st_ctime = _g_win32_filetime_to_unix_time (&handle_info->ftCreationTime, NULL);
statbuf->st_mtime = _g_win32_filetime_to_unix_time (&handle_info->ftLastWriteTime, NULL);
statbuf->st_atime = _g_win32_filetime_to_unix_time (&handle_info->ftLastAccessTime, NULL);
return 0;
}
/* Fills our private stat-like structure using data from
* a normal stat64 struct, BHFI, FSI and a reparse tag.
*/
static void
_g_win32_fill_privatestat (const struct __stat64 *statbuf,
const BY_HANDLE_FILE_INFORMATION *handle_info,
const FILE_STANDARD_INFO *std_info,
DWORD reparse_tag,
GWin32PrivateStat *buf)
{
gint32 nsec;
buf->st_dev = statbuf->st_dev;
buf->st_ino = statbuf->st_ino;
buf->st_mode = statbuf->st_mode;
buf->volume_serial = handle_info->dwVolumeSerialNumber;
buf->file_index = (((guint64) handle_info->nFileIndexHigh) << 32) | handle_info->nFileIndexLow;
buf->attributes = handle_info->dwFileAttributes;
buf->st_nlink = handle_info->nNumberOfLinks;
buf->st_size = (((guint64) handle_info->nFileSizeHigh) << 32) | handle_info->nFileSizeLow;
buf->allocated_size = std_info->AllocationSize.QuadPart;
buf->reparse_tag = reparse_tag;
buf->st_ctim.tv_sec = _g_win32_filetime_to_unix_time (&handle_info->ftCreationTime, &nsec);
buf->st_ctim.tv_nsec = nsec;
buf->st_mtim.tv_sec = _g_win32_filetime_to_unix_time (&handle_info->ftLastWriteTime, &nsec);
buf->st_mtim.tv_nsec = nsec;
buf->st_atim.tv_sec = _g_win32_filetime_to_unix_time (&handle_info->ftLastAccessTime, &nsec);
buf->st_atim.tv_nsec = nsec;
}
/* Read the link data from a symlink/mountpoint represented
* by the handle. Also reads reparse tag.
* @reparse_tag receives the tag. Can be %NULL if @buf or @alloc_buf
* is non-NULL.
* @buf receives the link data. Can be %NULL if reparse_tag is non-%NULL.
* Mutually-exclusive with @alloc_buf.
* @buf_size is the size of the @buf, in bytes.
* @alloc_buf points to a location where internally-allocated buffer
* pointer will be written. That buffer receives the
* link data. Mutually-exclusive with @buf.
* @terminate ensures that the buffer is NUL-terminated if
* it isn't already. Note that this can erase useful
* data if @buf is provided and @buf_size is too small.
* Specifically, with @buf_size <= 2 the buffer will
* receive an empty string, even if there is some
* data in the reparse point.
* The contents of @buf or @alloc_buf are presented as-is - could
* be non-NUL-terminated (unless @terminate is %TRUE) or even malformed.
* Returns the number of bytes (!) placed into @buf or @alloc_buf,
* including NUL-terminator (if any).
*
* Returned value of 0 means that there's no recognizable data in the
* reparse point. @alloc_buf will not be allocated in that case,
* and @buf will be left unmodified.
*
* If @buf and @alloc_buf are %NULL, returns 0 to indicate success.
* Returns -1 to indicate an error, sets errno.
*/
static int
_g_win32_readlink_handle_raw (HANDLE h,
DWORD *reparse_tag,
gunichar2 *buf,
gsize buf_size,
gunichar2 **alloc_buf,
gboolean terminate)
{
DWORD error_code;
DWORD returned_bytes = 0;
BYTE *data = NULL;
gsize to_copy;
/* This is 16k. It's impossible to make DeviceIoControl() tell us
* the required size. NtFsControlFile() does have such a feature,
* but for some reason it doesn't work with CreateFile()-returned handles.
* The only alternative is to repeatedly call DeviceIoControl()
* with bigger and bigger buffers, until it succeeds.
* We choose to sacrifice stack space for speed.
*/
BYTE max_buffer[sizeof (REPARSE_DATA_BUFFER) + MAXIMUM_REPARSE_DATA_BUFFER_SIZE] = {0,};
DWORD max_buffer_size = sizeof (REPARSE_DATA_BUFFER) + MAXIMUM_REPARSE_DATA_BUFFER_SIZE;
REPARSE_DATA_BUFFER *rep_buf;
g_return_val_if_fail ((buf != NULL || alloc_buf != NULL || reparse_tag != NULL) &&
(buf == NULL || alloc_buf == NULL),
-1);
if (!DeviceIoControl (h, FSCTL_GET_REPARSE_POINT, NULL, 0,
max_buffer,
max_buffer_size,
&returned_bytes, NULL))
{
error_code = GetLastError ();
errno = w32_error_to_errno (error_code);
return -1;
}
rep_buf = (REPARSE_DATA_BUFFER *) max_buffer;
if (reparse_tag != NULL)
*reparse_tag = rep_buf->ReparseTag;
if (buf == NULL && alloc_buf == NULL)
return 0;
if (rep_buf->ReparseTag == IO_REPARSE_TAG_SYMLINK)
{
data = &((BYTE *) rep_buf->SymbolicLinkReparseBuffer.PathBuffer)[rep_buf->SymbolicLinkReparseBuffer.SubstituteNameOffset];
to_copy = rep_buf->SymbolicLinkReparseBuffer.SubstituteNameLength;
}
else if (rep_buf->ReparseTag == IO_REPARSE_TAG_MOUNT_POINT)
{
data = &((BYTE *) rep_buf->MountPointReparseBuffer.PathBuffer)[rep_buf->MountPointReparseBuffer.SubstituteNameOffset];
to_copy = rep_buf->MountPointReparseBuffer.SubstituteNameLength;
}
else
to_copy = 0;
return _g_win32_copy_and_maybe_terminate (data, to_copy, buf, buf_size, alloc_buf, terminate);
}
/* Read the link data from a symlink/mountpoint represented
* by the @filename.
* @filename is the name of the file.
* @reparse_tag receives the tag. Can be %NULL if @buf or @alloc_buf
* is non-%NULL.
* @buf receives the link data. Mutually-exclusive with @alloc_buf.
* @buf_size is the size of the @buf, in bytes.
* @alloc_buf points to a location where internally-allocated buffer
* pointer will be written. That buffer receives the
* link data. Mutually-exclusive with @buf.
* @terminate ensures that the buffer is NUL-terminated if
* it isn't already
* The contents of @buf or @alloc_buf are presented as-is - could
* be non-NUL-terminated (unless @terminate is TRUE) or even malformed.
* Returns the number of bytes (!) placed into @buf or @alloc_buf.
* Returned value of 0 means that there's no recognizable data in the
* reparse point. @alloc_buf will not be allocated in that case,
* and @buf will be left unmodified.
* If @buf and @alloc_buf are %NULL, returns 0 to indicate success.
* Returns -1 to indicate an error, sets errno.
*/
static int
_g_win32_readlink_utf16_raw (const gunichar2 *filename,
DWORD *reparse_tag,
gunichar2 *buf,
gsize buf_size,
gunichar2 **alloc_buf,
gboolean terminate)
{
HANDLE h;
DWORD attributes;
DWORD to_copy;
DWORD error_code;
if ((attributes = GetFileAttributesW (filename)) == 0)
{
error_code = GetLastError ();
errno = w32_error_to_errno (error_code);
return -1;
}
if ((attributes & FILE_ATTRIBUTE_REPARSE_POINT) == 0)
{
errno = EINVAL;
return -1;
}
/* To read symlink target we need to open the file as a reparse
* point and use DeviceIoControl() on it.
*/
h = CreateFileW (filename,
FILE_READ_EA,
FILE_SHARE_READ|FILE_SHARE_WRITE|FILE_SHARE_DELETE,
NULL, OPEN_EXISTING,
FILE_ATTRIBUTE_NORMAL
| FILE_FLAG_OPEN_REPARSE_POINT
| (attributes & FILE_ATTRIBUTE_DIRECTORY ? FILE_FLAG_BACKUP_SEMANTICS : 0),
NULL);
if (h == INVALID_HANDLE_VALUE)
{
error_code = GetLastError ();
errno = w32_error_to_errno (error_code);
return -1;
}
to_copy = _g_win32_readlink_handle_raw (h, reparse_tag, buf, buf_size, alloc_buf, terminate);
CloseHandle (h);
return to_copy;
}
/* Read the link data from a symlink/mountpoint represented
* by a UTF-16 filename or a file handle.
* @filename is the name of the file. Mutually-exclusive with @file_handle.
* @file_handle is the handle of the file. Mutually-exclusive with @filename.
* @reparse_tag receives the tag. Can be %NULL if @buf or @alloc_buf
* is non-%NULL.
* @buf receives the link data. Mutually-exclusive with @alloc_buf.
* @buf_size is the size of the @buf, in bytes.
* @alloc_buf points to a location where internally-allocated buffer
* pointer will be written. That buffer receives the
* link data. Mutually-exclusive with @buf.
* @terminate ensures that the buffer is NUL-terminated if
* it isn't already
* The contents of @buf or @alloc_buf are adjusted
* (extended or nt object manager prefix is stripped),
* but otherwise they are presented as-is - could be non-NUL-terminated
* (unless @terminate is TRUE) or even malformed.
* Returns the number of bytes (!) placed into @buf or @alloc_buf.
* Returned value of 0 means that there's no recognizable data in the
* reparse point. @alloc_buf will not be allocated in that case,
* and @buf will be left unmodified.
* Returns -1 to indicate an error, sets errno.
*/
static int
_g_win32_readlink_utf16_handle (const gunichar2 *filename,
HANDLE file_handle,
DWORD *reparse_tag,
gunichar2 *buf,
gsize buf_size,
gunichar2 **alloc_buf,
gboolean terminate)
{
int result;
gsize string_size;
g_return_val_if_fail ((buf != NULL || alloc_buf != NULL || reparse_tag != NULL) &&
(filename != NULL || file_handle != NULL) &&
(buf == NULL || alloc_buf == NULL) &&
(filename == NULL || file_handle == NULL),
-1);
if (filename)
result = _g_win32_readlink_utf16_raw (filename, reparse_tag, buf, buf_size, alloc_buf, terminate);
else
result = _g_win32_readlink_handle_raw (file_handle, reparse_tag, buf, buf_size, alloc_buf, terminate);
if (result <= 0)
return result;
/* Ensure that output is a multiple of sizeof (gunichar2),
* cutting any trailing partial gunichar2, if present.
*/
result -= result % sizeof (gunichar2);
if (result <= 0)
return result;
/* DeviceIoControl () tends to return filenames as NT Object Manager
* names , i.e. "\\??\\C:\\foo\\bar".
* Remove the leading 4-byte "\\??\\" prefix, as glib (as well as many W32 API
* functions) is unprepared to deal with it. Unless it has no 'x:' drive
* letter part after the prefix, in which case we leave everything
* as-is, because the path could be "\\??\\Volume{GUID}" - stripping
* the prefix will allow it to be confused with relative links
* targeting "Volume{GUID}".
*/
string_size = result / sizeof (gunichar2);
_g_win32_strip_extended_ntobjm_prefix (buf ? buf : *alloc_buf, &string_size);
return string_size * sizeof (gunichar2);
}
/* Works like stat() or lstat(), depending on the value of @for_symlink,
* but accepts filename in UTF-16 and fills our custom stat structure.
* The @filename must not have trailing slashes.
*/
static int
_g_win32_stat_utf16_no_trailing_slashes (const gunichar2 *filename,
GWin32PrivateStat *buf,
gboolean for_symlink)
{
struct __stat64 statbuf;
BY_HANDLE_FILE_INFORMATION handle_info;
FILE_STANDARD_INFO std_info;
gboolean is_symlink = FALSE;
wchar_t *filename_target = NULL;
DWORD immediate_attributes;
DWORD open_flags;
gboolean is_directory;
DWORD reparse_tag = 0;
DWORD error_code;
BOOL succeeded_so_far;
HANDLE file_handle;
immediate_attributes = GetFileAttributesW (filename);
if (immediate_attributes == INVALID_FILE_ATTRIBUTES)
{
error_code = GetLastError ();
errno = w32_error_to_errno (error_code);
return -1;
}
is_symlink = (immediate_attributes & FILE_ATTRIBUTE_REPARSE_POINT) == FILE_ATTRIBUTE_REPARSE_POINT;
is_directory = (immediate_attributes & FILE_ATTRIBUTE_DIRECTORY) == FILE_ATTRIBUTE_DIRECTORY;
open_flags = FILE_ATTRIBUTE_NORMAL;
if (for_symlink && is_symlink)
open_flags |= FILE_FLAG_OPEN_REPARSE_POINT;
if (is_directory)
open_flags |= FILE_FLAG_BACKUP_SEMANTICS;
file_handle = CreateFileW (filename, FILE_READ_ATTRIBUTES | FILE_READ_EA,
FILE_SHARE_READ|FILE_SHARE_WRITE|FILE_SHARE_DELETE,
NULL, OPEN_EXISTING,
open_flags,
NULL);
if (file_handle == INVALID_HANDLE_VALUE)
{
error_code = GetLastError ();
errno = w32_error_to_errno (error_code);
return -1;
}
succeeded_so_far = GetFileInformationByHandle (file_handle,
&handle_info);
error_code = GetLastError ();
if (succeeded_so_far)
{
succeeded_so_far = GetFileInformationByHandleEx (file_handle,
FileStandardInfo,
&std_info,
sizeof (std_info));
error_code = GetLastError ();
}
if (!succeeded_so_far)
{
CloseHandle (file_handle);
errno = w32_error_to_errno (error_code);
return -1;
}
/* It's tempting to use GetFileInformationByHandleEx(FileAttributeTagInfo),
* but it always reports that the ReparseTag is 0.
* We already have a handle open for symlink, use that.
* For the target we have to specify a filename, and the function
* will open another handle internally.
*/
if (is_symlink &&
_g_win32_readlink_utf16_handle (for_symlink ? NULL : filename,
for_symlink ? file_handle : NULL,
&reparse_tag,
NULL, 0,
for_symlink ? NULL : &filename_target,
TRUE) < 0)
{
CloseHandle (file_handle);
return -1;
}
CloseHandle (file_handle);
_g_win32_fill_statbuf_from_handle_info (filename,
filename_target,
&handle_info,
&statbuf);
g_free (filename_target);
_g_win32_fill_privatestat (&statbuf,
&handle_info,
&std_info,
reparse_tag,
buf);
return 0;
}
/* Works like fstat(), but fills our custom stat structure. */
static int
_g_win32_stat_fd (int fd,
GWin32PrivateStat *buf)
{
HANDLE file_handle;
gboolean succeeded_so_far;
DWORD error_code;
struct __stat64 statbuf;
BY_HANDLE_FILE_INFORMATION handle_info;
FILE_STANDARD_INFO std_info;
DWORD reparse_tag = 0;
gboolean is_symlink = FALSE;
file_handle = (HANDLE) _get_osfhandle (fd);
if (file_handle == INVALID_HANDLE_VALUE)
return -1;
succeeded_so_far = GetFileInformationByHandle (file_handle,
&handle_info);
error_code = GetLastError ();
if (succeeded_so_far)
{
succeeded_so_far = GetFileInformationByHandleEx (file_handle,
FileStandardInfo,
&std_info,
sizeof (std_info));
error_code = GetLastError ();
}
if (!succeeded_so_far)
{
errno = w32_error_to_errno (error_code);
return -1;
}
is_symlink = (handle_info.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT) == FILE_ATTRIBUTE_REPARSE_POINT;
if (is_symlink &&
_g_win32_readlink_handle_raw (file_handle, &reparse_tag, NULL, 0, NULL, FALSE) < 0)
return -1;
if (_fstat64 (fd, &statbuf) != 0)
return -1;
_g_win32_fill_privatestat (&statbuf,
&handle_info,
&std_info,
reparse_tag,
buf);
return 0;
}
/* Works like stat() or lstat(), depending on the value of @for_symlink,
* but accepts filename in UTF-8 and fills our custom stat structure.
*/
static int
_g_win32_stat_utf8 (const gchar *filename,
GWin32PrivateStat *buf,
gboolean for_symlink)
{
wchar_t *wfilename;
int result;
gsize len;
if (filename == NULL)
{
errno = EINVAL;
return -1;
}
len = strlen (filename);
while (len > 0 && G_IS_DIR_SEPARATOR (filename[len - 1]))
len--;
if (len <= 0 ||
(g_path_is_absolute (filename) && len <= (gsize) (g_path_skip_root (filename) - filename)))
len = strlen (filename);
wfilename = g_utf8_to_utf16 (filename, len, NULL, NULL, NULL);
if (wfilename == NULL)
{
errno = EINVAL;
return -1;
}
result = _g_win32_stat_utf16_no_trailing_slashes (wfilename, buf, for_symlink);
g_free (wfilename);
return result;
}
/* Works like stat(), but accepts filename in UTF-8
* and fills our custom stat structure.
*/
int
g_win32_stat_utf8 (const gchar *filename,
GWin32PrivateStat *buf)
{
return _g_win32_stat_utf8 (filename, buf, FALSE);
}
/* Works like lstat(), but accepts filename in UTF-8
* and fills our custom stat structure.
*/
int
g_win32_lstat_utf8 (const gchar *filename,
GWin32PrivateStat *buf)
{
return _g_win32_stat_utf8 (filename, buf, TRUE);
}
/* Works like fstat(), but accepts filename in UTF-8
* and fills our custom stat structure.
*/
int
g_win32_fstat (int fd,
GWin32PrivateStat *buf)
{
return _g_win32_stat_fd (fd, buf);
}
/**
* g_win32_readlink_utf8:
* @filename: (type filename): a pathname in UTF-8
* @buf: (array length=buf_size) : a buffer to receive the reparse point
* target path. Mutually-exclusive
* with @alloc_buf.
* @buf_size: size of the @buf, in bytes
* @alloc_buf: points to a location where internally-allocated buffer
* pointer will be written. That buffer receives the
* link data. Mutually-exclusive with @buf.
* @terminate: ensures that the buffer is NUL-terminated if
* it isn't already. If %FALSE, the returned string
* might not be NUL-terminated (depends entirely on
* what the contents of the filesystem are).
*
* Tries to read the reparse point indicated by @filename, filling
* @buf or @alloc_buf with the path that the reparse point redirects to.
* The path will be UTF-8-encoded, and an extended path prefix
* or a NT object manager prefix will be removed from it, if
* possible, but otherwise the path is returned as-is. Specifically,
* it could be a "\\\\Volume{GUID}\\" path. It also might use
* backslashes as path separators.
*
* Returns: -1 on error (sets errno), 0 if there's no (recognizable)
* path in the reparse point (@alloc_buf will not be allocated in that case,
* and @buf will be left unmodified),
* or the number of bytes placed into @buf otherwise,
* including NUL-terminator (if present or if @terminate is TRUE).
* The buffer returned via @alloc_buf should be freed with g_free().
*
* Since: 2.60
*/
int
g_win32_readlink_utf8 (const gchar *filename,
gchar *buf,
gsize buf_size,
gchar **alloc_buf,
gboolean terminate)
{
wchar_t *wfilename;
int result;
wchar_t *buf_utf16;
glong tmp_len;
gchar *tmp;
g_return_val_if_fail ((buf != NULL || alloc_buf != NULL) &&
(buf == NULL || alloc_buf == NULL),
-1);
wfilename = g_utf8_to_utf16 (filename, -1, NULL, NULL, NULL);
if (wfilename == NULL)
{
errno = EINVAL;
return -1;
}
result = _g_win32_readlink_utf16_handle (wfilename, NULL, NULL,
NULL, 0, &buf_utf16, terminate);
g_free (wfilename);
if (result <= 0)
return result;
tmp = g_utf16_to_utf8 (buf_utf16,
result / sizeof (gunichar2),
NULL,
&tmp_len,
NULL);
g_free (buf_utf16);
if (tmp == NULL)
{
errno = EINVAL;
return -1;
}
if (alloc_buf)
{
*alloc_buf = tmp;
return tmp_len;
}
if ((gsize) tmp_len > buf_size)
tmp_len = buf_size;
memcpy (buf, tmp, tmp_len);
g_free (tmp);
return tmp_len;
}
#endif
/**
* g_access:
* @filename: (type filename): a pathname in the GLib file name encoding
* (UTF-8 on Windows)
* @mode: as in access()
*
* A wrapper for the POSIX access() function. This function is used to
* test a pathname for one or several of read, write or execute
* permissions, or just existence.
*
* On Windows, the file protection mechanism is not at all POSIX-like,
* and the underlying function in the C library only checks the
* FAT-style READONLY attribute, and does not look at the ACL of a
* file at all. This function is this in practise almost useless on
* Windows. Software that needs to handle file permissions on Windows
* more exactly should use the Win32 API.
*
* See your C library manual for more details about access().
*
* Returns: zero if the pathname refers to an existing file system
* object that has all the tested permissions, or -1 otherwise
* or on error.
*
* Since: 2.8
*/
int
g_access (const gchar *filename,
int mode)
{
#ifdef G_OS_WIN32
wchar_t *wfilename = g_utf8_to_utf16 (filename, -1, NULL, NULL, NULL);
int retval;
int save_errno;
if (wfilename == NULL)
{
errno = EINVAL;
return -1;
}
#ifndef X_OK
#define X_OK 1
#endif
retval = _waccess (wfilename, mode & ~X_OK);
save_errno = errno;
g_free (wfilename);
errno = save_errno;
return retval;
#else
return access (filename, mode);
#endif
}
/**
* g_chmod:
* @filename: (type filename): a pathname in the GLib file name encoding
* (UTF-8 on Windows)
* @mode: as in chmod()
*
* A wrapper for the POSIX chmod() function. The chmod() function is
* used to set the permissions of a file system object.
*
* On Windows the file protection mechanism is not at all POSIX-like,
* and the underlying chmod() function in the C library just sets or
* clears the FAT-style READONLY attribute. It does not touch any
* ACL. Software that needs to manage file permissions on Windows
* exactly should use the Win32 API.
*
* See your C library manual for more details about chmod().
*
* Returns: 0 if the operation succeeded, -1 on error
*
* Since: 2.8
*/
int
g_chmod (const gchar *filename,
int mode)
{
#ifdef G_OS_WIN32
wchar_t *wfilename = g_utf8_to_utf16 (filename, -1, NULL, NULL, NULL);
int retval;
int save_errno;
if (wfilename == NULL)
{
errno = EINVAL;
return -1;
}
retval = _wchmod (wfilename, mode);
save_errno = errno;
g_free (wfilename);
errno = save_errno;
return retval;
#else
return chmod (filename, mode);
#endif
}
/**
* g_open:
* @filename: (type filename): a pathname in the GLib file name encoding
* (UTF-8 on Windows)
* @flags: as in open()
* @mode: as in open()
*
* A wrapper for the POSIX open() function. The open() function is
* used to convert a pathname into a file descriptor.
*
* On POSIX systems file descriptors are implemented by the operating
* system. On Windows, it's the C library that implements open() and
* file descriptors. The actual Win32 API for opening files is quite
* different, see MSDN documentation for CreateFile(). The Win32 API
* uses file handles, which are more randomish integers, not small
* integers like file descriptors.
*
* Because file descriptors are specific to the C library on Windows,
* the file descriptor returned by this function makes sense only to
* functions in the same C library. Thus if the GLib-using code uses a
* different C library than GLib does, the file descriptor returned by
* this function cannot be passed to C library functions like write()
* or read().
*
* See your C library manual for more details about open().
*
* Returns: a new file descriptor, or -1 if an error occurred.
* The return value can be used exactly like the return value
* from open().
*
* Since: 2.6
*/
int
g_open (const gchar *filename,
int flags,
int mode)
{
#ifdef G_OS_WIN32
wchar_t *wfilename = g_utf8_to_utf16 (filename, -1, NULL, NULL, NULL);
int retval;
int save_errno;
if (wfilename == NULL)
{
errno = EINVAL;
return -1;
}
retval = _wopen (wfilename, flags, mode);
save_errno = errno;
g_free (wfilename);
errno = save_errno;
return retval;
#else
int fd;
do
fd = open (filename, flags, mode);
while (G_UNLIKELY (fd == -1 && errno == EINTR));
return fd;
#endif
}
/**
* g_creat:
* @filename: (type filename): a pathname in the GLib file name encoding
* (UTF-8 on Windows)
* @mode: as in creat()
*
* A wrapper for the POSIX creat() function. The creat() function is
* used to convert a pathname into a file descriptor, creating a file
* if necessary.
*
* On POSIX systems file descriptors are implemented by the operating
* system. On Windows, it's the C library that implements creat() and
* file descriptors. The actual Windows API for opening files is
* different, see MSDN documentation for CreateFile(). The Win32 API
* uses file handles, which are more randomish integers, not small
* integers like file descriptors.
*
* Because file descriptors are specific to the C library on Windows,
* the file descriptor returned by this function makes sense only to
* functions in the same C library. Thus if the GLib-using code uses a
* different C library than GLib does, the file descriptor returned by
* this function cannot be passed to C library functions like write()
* or read().
*
* See your C library manual for more details about creat().
*
* Returns: a new file descriptor, or -1 if an error occurred.
* The return value can be used exactly like the return value
* from creat().
*
* Since: 2.8
*/
int
g_creat (const gchar *filename,
int mode)
{
#ifdef G_OS_WIN32
wchar_t *wfilename = g_utf8_to_utf16 (filename, -1, NULL, NULL, NULL);
int retval;
int save_errno;
if (wfilename == NULL)
{
errno = EINVAL;
return -1;
}
retval = _wcreat (wfilename, mode);
save_errno = errno;
g_free (wfilename);
errno = save_errno;
return retval;
#else
return creat (filename, mode);
#endif
}
/**
* g_rename:
* @oldfilename: (type filename): a pathname in the GLib file name encoding
* (UTF-8 on Windows)
* @newfilename: (type filename): a pathname in the GLib file name encoding
*
* A wrapper for the POSIX rename() function. The rename() function
* renames a file, moving it between directories if required.
*
* See your C library manual for more details about how rename() works
* on your system. It is not possible in general on Windows to rename
* a file that is open to some process.
*
* Returns: 0 if the renaming succeeded, -1 if an error occurred
*
* Since: 2.6
*/
int
g_rename (const gchar *oldfilename,
const gchar *newfilename)
{
#ifdef G_OS_WIN32
wchar_t *woldfilename = g_utf8_to_utf16 (oldfilename, -1, NULL, NULL, NULL);
wchar_t *wnewfilename;
int retval;
int save_errno = 0;
if (woldfilename == NULL)
{
errno = EINVAL;
return -1;
}
wnewfilename = g_utf8_to_utf16 (newfilename, -1, NULL, NULL, NULL);
if (wnewfilename == NULL)
{
g_free (woldfilename);
errno = EINVAL;
return -1;
}
if (MoveFileExW (woldfilename, wnewfilename, MOVEFILE_REPLACE_EXISTING))
retval = 0;
else
{
retval = -1;
save_errno = w32_error_to_errno (GetLastError ());
}
g_free (woldfilename);
g_free (wnewfilename);
errno = save_errno;
return retval;
#else
return rename (oldfilename, newfilename);
#endif
}
/**
* g_mkdir:
* @filename: (type filename): a pathname in the GLib file name encoding
* (UTF-8 on Windows)
* @mode: permissions to use for the newly created directory
*
* A wrapper for the POSIX mkdir() function. The mkdir() function
* attempts to create a directory with the given name and permissions.
* The mode argument is ignored on Windows.
*
* See your C library manual for more details about mkdir().
*
* Returns: 0 if the directory was successfully created, -1 if an error
* occurred
*
* Since: 2.6
*/
int
g_mkdir (const gchar *filename,
int mode)
{
#ifdef G_OS_WIN32
wchar_t *wfilename = g_utf8_to_utf16 (filename, -1, NULL, NULL, NULL);
int retval;
int save_errno;
if (wfilename == NULL)
{
errno = EINVAL;
return -1;
}
retval = _wmkdir (wfilename);
save_errno = errno;
g_free (wfilename);
errno = save_errno;
return retval;
#else
return mkdir (filename, mode);
#endif
}
/**
* g_chdir:
* @path: (type filename): a pathname in the GLib file name encoding
* (UTF-8 on Windows)
*
* A wrapper for the POSIX chdir() function. The function changes the
* current directory of the process to @path.
*
* See your C library manual for more details about chdir().
*
* Returns: 0 on success, -1 if an error occurred.
*
* Since: 2.8
*/
int
g_chdir (const gchar *path)
{
#ifdef G_OS_WIN32
wchar_t *wpath = g_utf8_to_utf16 (path, -1, NULL, NULL, NULL);
int retval;
int save_errno;
if (wpath == NULL)
{
errno = EINVAL;
return -1;
}
retval = _wchdir (wpath);
save_errno = errno;
g_free (wpath);
errno = save_errno;
return retval;
#else
return chdir (path);
#endif
}
/**
* GStatBuf:
*
* A type corresponding to the appropriate struct type for the stat()
* system call, depending on the platform and/or compiler being used.
*
* See g_stat() for more information.
*/
/**
* g_stat:
* @filename: (type filename): a pathname in the GLib file name encoding
* (UTF-8 on Windows)
* @buf: a pointer to a stat struct, which will be filled with the file
* information
*
* A wrapper for the POSIX stat() function. The stat() function
* returns information about a file. On Windows the stat() function in
* the C library checks only the FAT-style READONLY attribute and does
* not look at the ACL at all. Thus on Windows the protection bits in
* the @st_mode field are a fabrication of little use.
*
* On Windows the Microsoft C libraries have several variants of the
* stat struct and stat() function with names like _stat(), _stat32(),
* _stat32i64() and _stat64i32(). The one used here is for 32-bit code
* the one with 32-bit size and time fields, specifically called _stat32().
*
* In Microsoft's compiler, by default struct stat means one with
* 64-bit time fields while in MinGW struct stat is the legacy one
* with 32-bit fields. To hopefully clear up this messs, the gstdio.h
* header defines a type #GStatBuf which is the appropriate struct type
* depending on the platform and/or compiler being used. On POSIX it
* is just struct stat, but note that even on POSIX platforms, stat()
* might be a macro.
*
* See your C library manual for more details about stat().
*
* Returns: 0 if the information was successfully retrieved,
* -1 if an error occurred
*
* Since: 2.6
*/
int
g_stat (const gchar *filename,
GStatBuf *buf)
{
#ifdef G_OS_WIN32
GWin32PrivateStat w32_buf;
int retval = g_win32_stat_utf8 (filename, &w32_buf);
buf->st_dev = w32_buf.st_dev;
buf->st_ino = w32_buf.st_ino;
buf->st_mode = w32_buf.st_mode;
buf->st_nlink = w32_buf.st_nlink;
buf->st_uid = w32_buf.st_uid;
buf->st_gid = w32_buf.st_gid;
buf->st_rdev = w32_buf.st_dev;
buf->st_size = w32_buf.st_size;
buf->st_atime = w32_buf.st_atim.tv_sec;
buf->st_mtime = w32_buf.st_mtim.tv_sec;
buf->st_ctime = w32_buf.st_ctim.tv_sec;
return retval;
#else
return stat (filename, buf);
#endif
}
/**
* g_lstat:
* @filename: (type filename): a pathname in the GLib file name encoding
* (UTF-8 on Windows)
* @buf: a pointer to a stat struct, which will be filled with the file
* information
*
* A wrapper for the POSIX lstat() function. The lstat() function is
* like stat() except that in the case of symbolic links, it returns
* information about the symbolic link itself and not the file that it
* refers to. If the system does not support symbolic links g_lstat()
* is identical to g_stat().
*
* See your C library manual for more details about lstat().
*
* Returns: 0 if the information was successfully retrieved,
* -1 if an error occurred
*
* Since: 2.6
*/
int
g_lstat (const gchar *filename,
GStatBuf *buf)
{
#ifdef HAVE_LSTAT
/* This can't be Win32, so don't do the widechar dance. */
return lstat (filename, buf);
#elif defined (G_OS_WIN32)
GWin32PrivateStat w32_buf;
int retval = g_win32_lstat_utf8 (filename, &w32_buf);
buf->st_dev = w32_buf.st_dev;
buf->st_ino = w32_buf.st_ino;
buf->st_mode = w32_buf.st_mode;
buf->st_nlink = w32_buf.st_nlink;
buf->st_uid = w32_buf.st_uid;
buf->st_gid = w32_buf.st_gid;
buf->st_rdev = w32_buf.st_dev;
buf->st_size = w32_buf.st_size;
buf->st_atime = w32_buf.st_atim.tv_sec;
buf->st_mtime = w32_buf.st_mtim.tv_sec;
buf->st_ctime = w32_buf.st_ctim.tv_sec;
return retval;
#else
return g_stat (filename, buf);
#endif
}
/**
* g_unlink:
* @filename: (type filename): a pathname in the GLib file name encoding
* (UTF-8 on Windows)
*
* A wrapper for the POSIX unlink() function. The unlink() function
* deletes a name from the filesystem. If this was the last link to the
* file and no processes have it opened, the diskspace occupied by the
* file is freed.
*
* See your C library manual for more details about unlink(). Note
* that on Windows, it is in general not possible to delete files that
* are open to some process, or mapped into memory.
*
* Returns: 0 if the name was successfully deleted, -1 if an error
* occurred
*
* Since: 2.6
*/
int
g_unlink (const gchar *filename)
{
#ifdef G_OS_WIN32
wchar_t *wfilename = g_utf8_to_utf16 (filename, -1, NULL, NULL, NULL);
int retval;
int save_errno;
if (wfilename == NULL)
{
errno = EINVAL;
return -1;
}
retval = _wunlink (wfilename);
save_errno = errno;
g_free (wfilename);
errno = save_errno;
return retval;
#else
return unlink (filename);
#endif
}
/**
* g_remove:
* @filename: (type filename): a pathname in the GLib file name encoding
* (UTF-8 on Windows)
*
* A wrapper for the POSIX remove() function. The remove() function
* deletes a name from the filesystem.
*
* See your C library manual for more details about how remove() works
* on your system. On Unix, remove() removes also directories, as it
* calls unlink() for files and rmdir() for directories. On Windows,
* although remove() in the C library only works for files, this
* function tries first remove() and then if that fails rmdir(), and
* thus works for both files and directories. Note however, that on
* Windows, it is in general not possible to remove a file that is
* open to some process, or mapped into memory.
*
* If this function fails on Windows you can't infer too much from the
* errno value. rmdir() is tried regardless of what caused remove() to
* fail. Any errno value set by remove() will be overwritten by that
* set by rmdir().
*
* Returns: 0 if the file was successfully removed, -1 if an error
* occurred
*
* Since: 2.6
*/
int
g_remove (const gchar *filename)
{
#ifdef G_OS_WIN32
wchar_t *wfilename = g_utf8_to_utf16 (filename, -1, NULL, NULL, NULL);
int retval;
int save_errno;
if (wfilename == NULL)
{
errno = EINVAL;
return -1;
}
retval = _wremove (wfilename);
if (retval == -1)
retval = _wrmdir (wfilename);
save_errno = errno;
g_free (wfilename);
errno = save_errno;
return retval;
#else
return remove (filename);
#endif
}
/**
* g_rmdir:
* @filename: (type filename): a pathname in the GLib file name encoding
* (UTF-8 on Windows)
*
* A wrapper for the POSIX rmdir() function. The rmdir() function
* deletes a directory from the filesystem.
*
* See your C library manual for more details about how rmdir() works
* on your system.
*
* Returns: 0 if the directory was successfully removed, -1 if an error
* occurred
*
* Since: 2.6
*/
int
g_rmdir (const gchar *filename)
{
#ifdef G_OS_WIN32
wchar_t *wfilename = g_utf8_to_utf16 (filename, -1, NULL, NULL, NULL);
int retval;
int save_errno;
if (wfilename == NULL)
{
errno = EINVAL;
return -1;
}
retval = _wrmdir (wfilename);
save_errno = errno;
g_free (wfilename);
errno = save_errno;
return retval;
#else
return rmdir (filename);
#endif
}
/**
* g_fopen:
* @filename: (type filename): a pathname in the GLib file name encoding
* (UTF-8 on Windows)
* @mode: a string describing the mode in which the file should be opened
*
* A wrapper for the stdio `fopen()` function. The `fopen()` function
* opens a file and associates a new stream with it.
*
* Because file descriptors are specific to the C library on Windows,
* and a file descriptor is part of the `FILE` struct, the `FILE*` returned
* by this function makes sense only to functions in the same C library.
* Thus if the GLib-using code uses a different C library than GLib does,
* the FILE* returned by this function cannot be passed to C library
* functions like `fprintf()` or `fread()`.
*
* See your C library manual for more details about `fopen()`.
*
* As `close()` and `fclose()` are part of the C library, this implies that it is
* currently impossible to close a file if the application C library and the C library
* used by GLib are different. Convenience functions like g_file_set_contents_full()
* avoid this problem.
*
* Returns: A `FILE*` if the file was successfully opened, or %NULL if
* an error occurred
*
* Since: 2.6
*/
FILE *
g_fopen (const gchar *filename,
const gchar *mode)
{
#ifdef G_OS_WIN32
wchar_t *wfilename = g_utf8_to_utf16 (filename, -1, NULL, NULL, NULL);
wchar_t *wmode;
FILE *retval;
int save_errno;
if (wfilename == NULL)
{
errno = EINVAL;
return NULL;
}
wmode = g_utf8_to_utf16 (mode, -1, NULL, NULL, NULL);
if (wmode == NULL)
{
g_free (wfilename);
errno = EINVAL;
return NULL;
}
_g_win32_fix_mode (wmode);
retval = _wfopen (wfilename, wmode);
save_errno = errno;
g_free (wfilename);
g_free (wmode);
errno = save_errno;
return retval;
#else
return fopen (filename, mode);
#endif
}
/**
* g_freopen:
* @filename: (type filename): a pathname in the GLib file name encoding
* (UTF-8 on Windows)
* @mode: a string describing the mode in which the file should be opened
* @stream: (nullable): an existing stream which will be reused, or %NULL
*
* A wrapper for the POSIX freopen() function. The freopen() function
* opens a file and associates it with an existing stream.
*
* See your C library manual for more details about freopen().
*
* Returns: A FILE* if the file was successfully opened, or %NULL if
* an error occurred.
*
* Since: 2.6
*/
FILE *
g_freopen (const gchar *filename,
const gchar *mode,
FILE *stream)
{
#ifdef G_OS_WIN32
wchar_t *wfilename = g_utf8_to_utf16 (filename, -1, NULL, NULL, NULL);
wchar_t *wmode;
FILE *retval;
int save_errno;
if (wfilename == NULL)
{
errno = EINVAL;
return NULL;
}
wmode = g_utf8_to_utf16 (mode, -1, NULL, NULL, NULL);
if (wmode == NULL)
{
g_free (wfilename);
errno = EINVAL;
return NULL;
}
_g_win32_fix_mode (wmode);
retval = _wfreopen (wfilename, wmode, stream);
save_errno = errno;
g_free (wfilename);
g_free (wmode);
errno = save_errno;
return retval;
#else
return freopen (filename, mode, stream);
#endif
}
/**
* g_fsync:
* @fd: a file descriptor
*
* A wrapper for the POSIX `fsync()` function. On Windows, `_commit()` will be
* used. On macOS, `fcntl(F_FULLFSYNC)` will be used.
* The `fsync()` function is used to synchronize a file's in-core
* state with that of the disk.
*
* This wrapper will handle retrying on `EINTR`.
*
* See the C library manual for more details about fsync().
*
* Returns: 0 on success, or -1 if an error occurred.
* The return value can be used exactly like the return value from fsync().
*
* Since: 2.64
*/
gint
g_fsync (gint fd)
{
#ifdef G_OS_WIN32
return _commit (fd);
#elif defined(HAVE_FSYNC) || defined(HAVE_FCNTL_F_FULLFSYNC)
int retval;
do
#ifdef HAVE_FCNTL_F_FULLFSYNC
retval = fcntl (fd, F_FULLFSYNC, 0);
#else
retval = fsync (fd);
#endif
while (G_UNLIKELY (retval < 0 && errno == EINTR));
return retval;
#else
return 0;
#endif
}
/**
* g_utime:
* @filename: (type filename): a pathname in the GLib file name encoding
* (UTF-8 on Windows)
* @utb: a pointer to a struct utimbuf.
*
* A wrapper for the POSIX utime() function. The utime() function
* sets the access and modification timestamps of a file.
*
* See your C library manual for more details about how utime() works
* on your system.
*
* Returns: 0 if the operation was successful, -1 if an error occurred
*
* Since: 2.18
*/
int
g_utime (const gchar *filename,
struct utimbuf *utb)
{
#ifdef G_OS_WIN32
wchar_t *wfilename = g_utf8_to_utf16 (filename, -1, NULL, NULL, NULL);
int retval;
int save_errno;
if (wfilename == NULL)
{
errno = EINVAL;
return -1;
}
retval = _wutime (wfilename, (struct _utimbuf*) utb);
save_errno = errno;
g_free (wfilename);
errno = save_errno;
return retval;
#else
return utime (filename, utb);
#endif
}
/**
* g_close:
* @fd: A file descriptor
* @error: a #GError
*
* This wraps the close() call. In case of error, %errno will be
* preserved, but the error will also be stored as a #GError in @error.
* In case of success, %errno is undefined.
*
* Besides using #GError, there is another major reason to prefer this
* function over the call provided by the system; on Unix, it will
* attempt to correctly handle %EINTR, which has platform-specific
* semantics.
*
* It is a bug to call this function with an invalid file descriptor.
*
* On POSIX platforms since GLib 2.76, this function is async-signal safe
* if (and only if) @error is %NULL and @fd is a valid open file descriptor.
* This makes it safe to call from a signal handler or a #GSpawnChildSetupFunc
* under those conditions.
* See [`signal(7)`](man:signal(7)) and
* [`signal-safety(7)`](man:signal-safety(7)) for more details.
*
* Returns: %TRUE on success, %FALSE if there was an error.
*
* Since: 2.36
*/
gboolean
g_close (gint fd,
GError **error)
{
int res;
/* Important: if @error is NULL, we must not do anything that is
* not async-signal-safe.
*/
res = close (fd);
if (res == -1)
{
int errsv = errno;
if (errsv == EINTR)
{
/* Just ignore EINTR for now; a retry loop is the wrong thing to do
* on Linux at least. Anyone who wants to add a conditional check
* for e.g. HP-UX is welcome to do so later...
*
* close_func_with_invalid_fds() in gspawn.c has similar logic.
*
* https://lwn.net/Articles/576478/
* http://lkml.indiana.edu/hypermail/linux/kernel/0509.1/0877.html
* https://bugzilla.gnome.org/show_bug.cgi?id=682819
* http://utcc.utoronto.ca/~cks/space/blog/unix/CloseEINTR
* https://sites.google.com/site/michaelsafyan/software-engineering/checkforeintrwheninvokingclosethinkagain
*
* `close$NOCANCEL()` in gstdioprivate.h, on macOS, ensures that the fd is
* closed even if it did return EINTR.
*/
return TRUE;
}
if (error)
{
g_set_error_literal (error, G_FILE_ERROR,
g_file_error_from_errno (errsv),
g_strerror (errsv));
}
if (errsv == EBADF)
{
/* There is a bug. Fail an assertion. Note that this function is supposed to be
* async-signal-safe, but in case an assertion fails, all bets are already off. */
if (fd >= 0)
{
/* Closing an non-negative, invalid file descriptor is a bug. The bug is
* not necessarily in the caller of g_close(), but somebody else
* might have wrongly closed fd. In any case, there is a serious bug
* somewhere. */
g_critical ("g_close(fd:%d) failed with EBADF. The tracking of file descriptors got messed up", fd);
}
else
{
/* Closing a negative "file descriptor" is less problematic. It's still a nonsensical action
* from the caller. Assert against that too. */
g_critical ("g_close(fd:%d) failed with EBADF. This is not a valid file descriptor", fd);
}
}
errno = errsv;
return FALSE;
}
return TRUE;
}
/**
* g_clear_fd: (skip)
* @fd_ptr: (not optional) (inout) (transfer full): a pointer to a file descriptor
* @error: Used to return an error on failure
*
* If @fd_ptr points to a file descriptor, close it and return
* whether closing it was successful, like g_close().
* If @fd_ptr points to a negative number, return %TRUE without closing
* anything.
* In both cases, set @fd_ptr to `-1` before returning.
*
* Like g_close(), if closing the file descriptor fails, the error is
* stored in both %errno and @error. If this function succeeds,
* %errno is undefined.
*
* On POSIX platforms, this function is async-signal safe
* if @error is %NULL and @fd_ptr points to either a negative number or a
* valid open file descriptor.
* This makes it safe to call from a signal handler or a #GSpawnChildSetupFunc
* under those conditions.
* See [`signal(7)`](man:signal(7)) and
* [`signal-safety(7)`](man:signal-safety(7)) for more details.
*
* It is a programming error for @fd_ptr to point to a non-negative
* number that is not a valid file descriptor.
*
* A typical use of this function is to clean up a file descriptor at
* the end of its scope, whether it has been set successfully or not:
*
* |[
* gboolean
* operate_on_fd (GError **error)
* {
* gboolean ret = FALSE;
* int fd = -1;
*
* fd = open_a_fd (error);
*
* if (fd < 0)
* goto out;
*
* if (!do_something (fd, error))
* goto out;
*
* if (!g_clear_fd (&fd, error))
* goto out;
*
* ret = TRUE;
*
* out:
* // OK to call even if fd was never opened or was already closed
* g_clear_fd (&fd, NULL);
* return ret;
* }
* ]|
*
* This function is also useful in conjunction with #g_autofd.
*
* Returns: %TRUE on success
* Since: 2.76
*/
/**
* g_autofd: (skip)
*
* Macro to add an attribute to a file descriptor variable to ensure
* automatic cleanup using g_clear_fd().
*
* This macro behaves like #g_autofree rather than g_autoptr(): it is
* an attribute supplied before the type name, rather than wrapping the
* type definition.
*
* Otherwise, this macro has similar constraints as g_autoptr(): it is
* only supported on GCC and clang, and the variable must be initialized
* (to either a valid file descriptor or a negative number).
*
* Using this macro is async-signal-safe if the constraints described above
* are met, so it can be used in a signal handler or after `fork()`.
*
* Any error from closing the file descriptor when it goes out of scope
* is ignored. Use g_clear_fd() if error-checking is required.
*
* |[
* gboolean
* operate_on_fds (GError **error)
* {
* g_autofd int fd1 = open_a_fd (..., error);
* g_autofd int fd2 = -1;
*
* // it is safe to return early here, nothing will be closed
* if (fd1 < 0)
* return FALSE;
*
* fd2 = open_a_fd (..., error);
*
* // fd1 will be closed automatically if we return here
* if (fd2 < 0)
* return FALSE;
*
* // fd1 and fd2 will be closed automatically if we return here
* if (!do_something_useful (fd1, fd2, error))
* return FALSE;
*
* // fd2 will be closed automatically if we return here
* if (!g_clear_fd (&fd1, error))
* return FALSE;
*
* // fd2 will be automatically closed here if still open
* return TRUE;
* }
* ]|
*
* Since: 2.76
*/
Reference in New Issue View Git Blame Copy Permalink