luc14n0/glib
1
0
Fork 0
mirror of https://gitlab.gnome.org/GNOME/glib.git synced 2025-02-22 18:22:11 +01:00
Code Issues Packages Projects Releases Wiki Activity
glib/glib/gstdio.c
Руслан Ижбулатов d3d6ef60c6 W32: drop _wstat64(), get stat data manually 
It turns out that UCRT (which is the C runtime that Visual Studio
uses by default these days) quietly changed the semantics for
stat() functions and its variants. Previously they provided data
for the symlink (if the file queried was a symlink), now they
provide data for the target of the symlink.

glib used to call _wstat64() to get certain stat-ish data about
files, such as st_dev, since it was deemed that computing that
data in glib using custom code would be pointless, as _wstat64()
worked just fine.

With UCRT this is no longer true. This commit drops _wstat64() in
favour of a bunch of custom calls that populate the stat buffer
manually. This way glib correctly gets information about a symlink,
not its target.

The _fstat64() call is still being used, as it does not suffer
from this problem and thus remains untouched.
2018-09-18 12:45:05 +00:00

1628 lines
44 KiB
C
Raw Blame History

/* gstdio.c - wrappers for C library functions
*
* Copyright 2004 Tor Lillqvist
*
* 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"
#define G_STDIO_NO_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_INVALID_HANDLE:
return EBADF;
break;
case ERROR_INVALID_FUNCTION:
return EFAULT;
break;
case ERROR_FILE_NOT_FOUND:
return ENOENT;
break;
case ERROR_PATH_NOT_FOUND:
return ENOENT; /* or ELOOP, or ENAMETOOLONG */
break;
case ERROR_NOT_ENOUGH_MEMORY:
case ERROR_OUTOFMEMORY:
return ENOMEM;
break;
default:
return EIO;
break;
}
}
#include "gstdio-private.c"
/* 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.
*/
static gint64
_g_win32_filetime_to_unix_time (FILETIME *ft)
{
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);
return (result - filetime_unix_epoch_offset) / 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
static int
_g_win32_fill_statbuf_from_handle_info (const wchar_t *filename,
const wchar_t *filename_target,
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);
statbuf->st_mtime = _g_win32_filetime_to_unix_time (&handle_info->ftLastWriteTime);
statbuf->st_atime = _g_win32_filetime_to_unix_time (&handle_info->ftLastAccessTime);
return 0;
}
static int
_g_win32_stat_utf16_no_trailing_slashes (const gunichar2 *filename,
int fd,
GWin32PrivateStat *buf,
gboolean for_symlink)
{
HANDLE file_handle;
gboolean succeeded_so_far;
DWORD error_code;
struct __stat64 statbuf;
BY_HANDLE_FILE_INFORMATION handle_info;
FILE_STANDARD_INFO std_info;
WIN32_FIND_DATAW finddata;
DWORD immediate_attributes;
gboolean is_symlink = FALSE;
gboolean is_directory;
DWORD open_flags;
wchar_t *filename_target = NULL;
int result;
if (fd < 0)
{
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_SHARE_READ, NULL, OPEN_EXISTING,
open_flags,
NULL);
if (file_handle == INVALID_HANDLE_VALUE)
{
error_code = GetLastError ();
errno = w32_error_to_errno (error_code);
return -1;
}
}
else
{
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)
{
if (fd < 0)
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.
*/
if (fd < 0)
{
memset (&finddata, 0, sizeof (finddata));
if (handle_info.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT)
{
HANDLE tmp = FindFirstFileW (filename,
&finddata);
if (tmp == INVALID_HANDLE_VALUE)
{
error_code = GetLastError ();
errno = w32_error_to_errno (error_code);
CloseHandle (file_handle);
return -1;
}
FindClose (tmp);
}
if (is_symlink && !for_symlink)
{
/* If filename is a symlink, but we need the target.
* To get information about the target we need to resolve
* the symlink first.
*/
DWORD filename_target_len;
DWORD new_len;
/* Just in case, give it a real memory location instead of NULL */
new_len = GetFinalPathNameByHandleW (file_handle,
(wchar_t *) &filename_target_len,
0,
FILE_NAME_NORMALIZED);
#define SANE_LIMIT 1024 * 10
if (new_len >= SANE_LIMIT)
#undef SANE_LIMIT
{
new_len = 0;
error_code = ERROR_BUFFER_OVERFLOW;
}
else if (new_len == 0)
{
error_code = GetLastError ();
}
if (new_len > 0)
{
/* Pretend that new_len doesn't count the terminating NUL char,
* and ask for a bit more space than is needed, and allocate even more.
*/
filename_target_len = new_len + 3;
filename_target = g_malloc ((filename_target_len + 1) * sizeof (wchar_t));
new_len = GetFinalPathNameByHandleW (file_handle,
filename_target,
filename_target_len,
FILE_NAME_NORMALIZED);
/* filename_target_len is already larger than needed,
* new_len should be smaller than that, even if the size
* is off by 1 for some reason.
*/
if (new_len >= filename_target_len - 1)
{
new_len = 0;
error_code = ERROR_BUFFER_OVERFLOW;
g_clear_pointer (&filename_target, g_free);
}
else if (new_len == 0)
{
g_clear_pointer (&filename_target, g_free);
}
/* GetFinalPathNameByHandle() is documented to return extended paths,
* strip the extended prefix, if it is followed by a drive letter
* and a colon. Otherwise keep it (the path could be
* \\\\?\\Volume{GUID}\\ - it's only usable in extended form).
*/
else if (new_len > 0)
{
gsize len = new_len;
/* Account for NUL-terminator maybe not being counted.
* This is why we overallocated earlier.
*/
if (filename_target[len] != L'\0')
{
len++;
filename_target[len] = L'\0';
}
_g_win32_strip_extended_ntobjm_prefix (filename_target, &len);
new_len = len;
}
}
if (new_len == 0)
succeeded_so_far = FALSE;
}
CloseHandle (file_handle);
}
/* else if fd >= 0 the file_handle was obtained via _get_osfhandle()
* and must not be closed, it is owned by fd.
*/
if (!succeeded_so_far)
{
errno = w32_error_to_errno (error_code);
return -1;
}
/*
* We can't use _wstat64() here, because with UCRT it now gives
* information about the target, even if we want information about
* the link itself (unlike MSVCRT, which gave information about
* the link, and if we needed information about the target we were
* able to resolve it by ourselves prior to calling _wstat64()).
*/
if (fd < 0)
result = _g_win32_fill_statbuf_from_handle_info (filename,
filename_target,
&handle_info,
&statbuf);
else
result = _fstat64 (fd, &statbuf);
if (result != 0)
{
int errsv = errno;
g_free (filename_target);
errno = errsv;
return -1;
}
g_free (filename_target);
buf->st_dev = statbuf.st_dev;
buf->st_mode = statbuf.st_mode;
buf->volume_serial = handle_info.dwVolumeSerialNumber;
buf->file_index = (((guint64) handle_info.nFileIndexHigh) << 32) | handle_info.nFileIndexLow;
/* Note that immediate_attributes is for the symlink
* (if it's a symlink), while handle_info contains info
* about the symlink or the target, depending on the flags
* we used earlier.
*/
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;
if (fd < 0 && buf->attributes & FILE_ATTRIBUTE_REPARSE_POINT)
buf->reparse_tag = finddata.dwReserved0;
else
buf->reparse_tag = 0;
buf->st_ctime = statbuf.st_ctime;
buf->st_atime = statbuf.st_atime;
buf->st_mtime = statbuf.st_mtime;
return 0;
}
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 <= 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, -1, buf, for_symlink);
g_free (wfilename);
return result;
}
int
g_win32_stat_utf8 (const gchar *filename,
GWin32PrivateStat *buf)
{
return _g_win32_stat_utf8 (filename, buf, FALSE);
}
int
g_win32_lstat_utf8 (const gchar *filename,
GWin32PrivateStat *buf)
{
return _g_win32_stat_utf8 (filename, buf, TRUE);
}
int
g_win32_fstat (int fd,
GWin32PrivateStat *buf)
{
return _g_win32_stat_utf16_no_trailing_slashes (NULL, fd, buf, FALSE);
}
static int
_g_win32_readlink_utf16_raw (const gunichar2 *filename,
gunichar2 *buf,
gsize buf_size)
{
DWORD returned_bytes;
BYTE returned_data[MAXIMUM_REPARSE_DATA_BUFFER_SIZE]; /* This is 16k, by the way */
HANDLE h;
DWORD attributes;
REPARSE_DATA_BUFFER *rep_buf;
DWORD to_copy;
DWORD error_code;
if (buf_size > G_MAXSIZE / sizeof (wchar_t))
{
/* "buf_size * sizeof (wchar_t)" overflows */
errno = EFAULT;
return -1;
}
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;
}
if (!DeviceIoControl (h, FSCTL_GET_REPARSE_POINT, NULL, 0,
returned_data, MAXIMUM_REPARSE_DATA_BUFFER_SIZE,
&returned_bytes, NULL))
{
error_code = GetLastError ();
errno = w32_error_to_errno (error_code);
CloseHandle (h);
return -1;
}
rep_buf = (REPARSE_DATA_BUFFER *) returned_data;
to_copy = 0;
if (rep_buf->ReparseTag == IO_REPARSE_TAG_SYMLINK)
{
to_copy = rep_buf->SymbolicLinkReparseBuffer.SubstituteNameLength;
if (to_copy > buf_size * sizeof (wchar_t))
to_copy = buf_size * sizeof (wchar_t);
memcpy (buf,
&((BYTE *) rep_buf->SymbolicLinkReparseBuffer.PathBuffer)[rep_buf->SymbolicLinkReparseBuffer.SubstituteNameOffset],
to_copy);
}
else if (rep_buf->ReparseTag == IO_REPARSE_TAG_MOUNT_POINT)
{
to_copy = rep_buf->MountPointReparseBuffer.SubstituteNameLength;
if (to_copy > buf_size * sizeof (wchar_t))
to_copy = buf_size * sizeof (wchar_t);
memcpy (buf,
&((BYTE *) rep_buf->MountPointReparseBuffer.PathBuffer)[rep_buf->MountPointReparseBuffer.SubstituteNameOffset],
to_copy);
}
CloseHandle (h);
return to_copy;
}
static int
_g_win32_readlink_utf16 (const gunichar2 *filename,
gunichar2 *buf,
gsize buf_size)
{
int result = _g_win32_readlink_utf16_raw (filename, buf, buf_size);
gsize string_size;
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, &string_size);
return string_size * sizeof (gunichar2);
}
static gchar *
_g_win32_get_mode_alias (const gchar *mode)
{
gchar *alias;
alias = g_strdup (mode);
if (strlen (mode) > 2 && mode[2] == '+')
{
/* 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.
*/
alias[1] = '+';
alias[2] = mode[1];
}
return alias;
}
int
g_win32_readlink_utf8 (const gchar *filename,
gchar *buf,
gsize buf_size)
{
wchar_t *wfilename;
int result;
wfilename = g_utf8_to_utf16 (filename, -1, NULL, NULL, NULL);
if (wfilename == NULL)
{
errno = EINVAL;
return -1;
}
result = _g_win32_readlink_utf16 (wfilename, (gunichar2 *) buf, buf_size);
g_free (wfilename);
if (result > 0)
{
glong tmp_len;
gchar *tmp = g_utf16_to_utf8 ((const gunichar2 *) buf,
result / sizeof (gunichar2),
NULL,
&tmp_len,
NULL);
if (tmp == NULL)
{
errno = EINVAL;
return -1;
}
if (tmp_len > buf_size - 1)
tmp_len = buf_size - 1;
memcpy (buf, tmp, tmp_len);
/* readlink() doesn't NUL-terminate, but we do.
* To be compliant, however, we return the
* number of bytes without the NUL-terminator.
*/
buf[tmp_len] = '\0';
result = tmp_len;
g_free (tmp);
}
return result;
}
#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;
switch (GetLastError ())
{
#define CASE(a,b) case ERROR_##a: save_errno = b; break
CASE (FILE_NOT_FOUND, ENOENT);
CASE (PATH_NOT_FOUND, ENOENT);
CASE (ACCESS_DENIED, EACCES);
CASE (NOT_SAME_DEVICE, EXDEV);
CASE (LOCK_VIOLATION, EACCES);
CASE (SHARING_VIOLATION, EACCES);
CASE (FILE_EXISTS, EEXIST);
CASE (ALREADY_EXISTS, EEXIST);
#undef CASE
default: save_errno = EIO;
}
}
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_atime;
buf->st_mtime = w32_buf.st_mtime;
buf->st_ctime = w32_buf.st_ctime;
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_atime;
buf->st_mtime = w32_buf.st_mtime;
buf->st_ctime = w32_buf.st_ctime;
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().
*
* 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;
gchar *mode2;
FILE *retval;
int save_errno;
if (wfilename == NULL)
{
errno = EINVAL;
return NULL;
}
mode2 = _g_win32_get_mode_alias (mode);
wmode = g_utf8_to_utf16 (mode2, -1, NULL, NULL, NULL);
g_free (mode2);
if (wmode == NULL)
{
g_free (wfilename);
errno = EINVAL;
return NULL;
}
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;
gchar *mode2;
FILE *retval;
int save_errno;
if (wfilename == NULL)
{
errno = EINVAL;
return NULL;
}
mode2 = _g_win32_get_mode_alias (mode);
wmode = g_utf8_to_utf16 (mode2, -1, NULL, NULL, NULL);
g_free (mode2);
if (wmode == NULL)
{
g_free (wfilename);
errno = EINVAL;
return NULL;
}
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_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.
*
* 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.
*
* Returns: %TRUE on success, %FALSE if there was an error.
*
* Since: 2.36
*/
gboolean
g_close (gint fd,
GError **error)
{
int res;
res = close (fd);
/* 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...
*
* 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
*/
if (G_UNLIKELY (res == -1 && errno == EINTR))
return TRUE;
else if (res == -1)
{
int errsv = errno;
g_set_error_literal (error, G_FILE_ERROR,
g_file_error_from_errno (errsv),
g_strerror (errsv));
errno = errsv;
return FALSE;
}
return TRUE;
}
Reference in New Issue View Git Blame Copy Permalink