luc14n0/glib
1
0
Fork 0
mirror of https://gitlab.gnome.org/GNOME/glib.git synced 2024-09-20 17:26:14 +02:00
Code Issues Packages Projects Releases Wiki Activity
85af9b73c9
glib/glib/gfileutils.c
Philip Withnall 7a5d4c2bb7 gfileutils: Fix potential integer overflow in g_get_current_dir() 
In practice, this will never happen.

If `getcwd()` returns `ERANGE` whenever the working directory is ≥
`PATH_MAX`, though, the previous implementation of the loop would run
until `max_len == G_MAXULONG`, and would then overflow when adding `1`
to it for a nul terminator in the allocation.

Avoid that problem by always keeping `buffer_len` as a power of two, and
relying on `getcwd()` to write a nul terminator within the buffer space
it’s given. It seems to do this on all platforms we care about, because
the previous version of the code never explicitly wrote a nul terminator
anywhere.

Signed-off-by: Philip Withnall <pwithnall@endlessos.org>

Fixes: #98
2023-04-14 19:23:20 +01:00

3043 lines
85 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.

/* gfileutils.c - File utility functions
*
* Copyright 2000 Red Hat, Inc.
*
* 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"
#include <sys/stat.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdlib.h>
#ifdef G_OS_UNIX
#include <unistd.h>
#endif
#ifdef G_OS_WIN32
#include <windows.h>
#include <io.h>
#endif /* G_OS_WIN32 */
#ifndef S_ISLNK
#define S_ISLNK(x) 0
#endif
#ifndef O_BINARY
#define O_BINARY 0
#endif
#ifndef O_CLOEXEC
#define O_CLOEXEC 0
#endif
#include "gfileutils.h"
#include "gstdio.h"
#include "gstdioprivate.h"
#include "glibintl.h"
/**
* SECTION:fileutils
* @title: File Utilities
* @short_description: various file-related functions
*
* Do not use these APIs unless you are porting a POSIX application to Windows.
* A more high-level file access API is provided as GIO — see the documentation
* for #GFile.
*
* There is a group of functions which wrap the common POSIX functions
* dealing with filenames (g_open(), g_rename(), g_mkdir(), g_stat(),
* g_unlink(), g_remove(), g_fopen(), g_freopen()). The point of these
* wrappers is to make it possible to handle file names with any Unicode
* characters in them on Windows without having to use ifdefs and the
* wide character API in the application code.
*
* On some Unix systems, these APIs may be defined as identical to their POSIX
* counterparts. For this reason, you must check for and include the necessary
* header files (such as `fcntl.h`) before using functions like g_creat(). You
* must also define the relevant feature test macros.
*
* The pathname argument should be in the GLib file name encoding.
* On POSIX this is the actual on-disk encoding which might correspond
* to the locale settings of the process (or the `G_FILENAME_ENCODING`
* environment variable), or not.
*
* On Windows the GLib file name encoding is UTF-8. Note that the
* Microsoft C library does not use UTF-8, but has separate APIs for
* current system code page and wide characters (UTF-16). The GLib
* wrappers call the wide character API if present (on modern Windows
* systems), otherwise convert to/from the system code page.
*
* Another group of functions allows to open and read directories
* in the GLib file name encoding. These are g_dir_open(),
* g_dir_read_name(), g_dir_rewind(), g_dir_close().
*/
/**
* GFileError:
* @G_FILE_ERROR_EXIST: Operation not permitted; only the owner of
* the file (or other resource) or processes with special privileges
* can perform the operation.
* @G_FILE_ERROR_ISDIR: File is a directory; you cannot open a directory
* for writing, or create or remove hard links to it.
* @G_FILE_ERROR_ACCES: Permission denied; the file permissions do not
* allow the attempted operation.
* @G_FILE_ERROR_NAMETOOLONG: Filename too long.
* @G_FILE_ERROR_NOENT: No such file or directory. This is a "file
* doesn't exist" error for ordinary files that are referenced in
* contexts where they are expected to already exist.
* @G_FILE_ERROR_NOTDIR: A file that isn't a directory was specified when
* a directory is required.
* @G_FILE_ERROR_NXIO: No such device or address. The system tried to
* use the device represented by a file you specified, and it
* couldn't find the device. This can mean that the device file was
* installed incorrectly, or that the physical device is missing or
* not correctly attached to the computer.
* @G_FILE_ERROR_NODEV: The underlying file system of the specified file
* does not support memory mapping.
* @G_FILE_ERROR_ROFS: The directory containing the new link can't be
* modified because it's on a read-only file system.
* @G_FILE_ERROR_TXTBSY: Text file busy.
* @G_FILE_ERROR_FAULT: You passed in a pointer to bad memory.
* (GLib won't reliably return this, don't pass in pointers to bad
* memory.)
* @G_FILE_ERROR_LOOP: Too many levels of symbolic links were encountered
* in looking up a file name. This often indicates a cycle of symbolic
* links.
* @G_FILE_ERROR_NOSPC: No space left on device; write operation on a
* file failed because the disk is full.
* @G_FILE_ERROR_NOMEM: No memory available. The system cannot allocate
* more virtual memory because its capacity is full.
* @G_FILE_ERROR_MFILE: The current process has too many files open and
* can't open any more. Duplicate descriptors do count toward this
* limit.
* @G_FILE_ERROR_NFILE: There are too many distinct file openings in the
* entire system.
* @G_FILE_ERROR_BADF: Bad file descriptor; for example, I/O on a
* descriptor that has been closed or reading from a descriptor open
* only for writing (or vice versa).
* @G_FILE_ERROR_INVAL: Invalid argument. This is used to indicate
* various kinds of problems with passing the wrong argument to a
* library function.
* @G_FILE_ERROR_PIPE: Broken pipe; there is no process reading from the
* other end of a pipe. Every library function that returns this
* error code also generates a 'SIGPIPE' signal; this signal
* terminates the program if not handled or blocked. Thus, your
* program will never actually see this code unless it has handled
* or blocked 'SIGPIPE'.
* @G_FILE_ERROR_AGAIN: Resource temporarily unavailable; the call might
* work if you try again later.
* @G_FILE_ERROR_INTR: Interrupted function call; an asynchronous signal
* occurred and prevented completion of the call. When this
* happens, you should try the call again.
* @G_FILE_ERROR_IO: Input/output error; usually used for physical read
* or write errors. i.e. the disk or other physical device hardware
* is returning errors.
* @G_FILE_ERROR_PERM: Operation not permitted; only the owner of the
* file (or other resource) or processes with special privileges can
* perform the operation.
* @G_FILE_ERROR_NOSYS: Function not implemented; this indicates that
* the system is missing some functionality.
* @G_FILE_ERROR_FAILED: Does not correspond to a UNIX error code; this
* is the standard "failed for unspecified reason" error code present
* in all #GError error code enumerations. Returned if no specific
* code applies.
*
* Values corresponding to @errno codes returned from file operations
* on UNIX. Unlike @errno codes, GFileError values are available on
* all systems, even Windows. The exact meaning of each code depends
* on what sort of file operation you were performing; the UNIX
* documentation gives more details. The following error code descriptions
* come from the GNU C Library manual, and are under the copyright
* of that manual.
*
* It's not very portable to make detailed assumptions about exactly
* which errors will be returned from a given operation. Some errors
* don't occur on some systems, etc., sometimes there are subtle
* differences in when a system will report a given error, etc.
*/
/**
* G_FILE_ERROR:
*
* Error domain for file operations. Errors in this domain will
* be from the #GFileError enumeration. See #GError for information
* on error domains.
*/
/**
* GFileTest:
* @G_FILE_TEST_IS_REGULAR: %TRUE if the file is a regular file
* (not a directory). Note that this test will also return %TRUE
* if the tested file is a symlink to a regular file.
* @G_FILE_TEST_IS_SYMLINK: %TRUE if the file is a symlink.
* @G_FILE_TEST_IS_DIR: %TRUE if the file is a directory.
* @G_FILE_TEST_IS_EXECUTABLE: %TRUE if the file is executable.
* @G_FILE_TEST_EXISTS: %TRUE if the file exists. It may or may not
* be a regular file.
*
* A test to perform on a file using g_file_test().
*/
/**
* g_mkdir_with_parents:
* @pathname: (type filename): a pathname in the GLib file name encoding
* @mode: permissions to use for newly created directories
*
* Create a directory if it doesn't already exist. Create intermediate
* parent directories as needed, too.
*
* Returns: 0 if the directory already exists, or was successfully
* created. Returns -1 if an error occurred, with errno set.
*
* Since: 2.8
*/
int
g_mkdir_with_parents (const gchar *pathname,
int mode)
{
gchar *fn, *p;
if (pathname == NULL || *pathname == '\0')
{
errno = EINVAL;
return -1;
}
/* try to create the full path first */
if (g_mkdir (pathname, mode) == 0)
return 0;
else if (errno == EEXIST)
{
if (!g_file_test (pathname, G_FILE_TEST_IS_DIR))
{
errno = ENOTDIR;
return -1;
}
return 0;
}
/* walk the full path and try creating each element */
fn = g_strdup (pathname);
if (g_path_is_absolute (fn))
p = (gchar *) g_path_skip_root (fn);
else
p = fn;
do
{
while (*p && !G_IS_DIR_SEPARATOR (*p))
p++;
if (!*p)
p = NULL;
else
*p = '\0';
if (!g_file_test (fn, G_FILE_TEST_EXISTS))
{
if (g_mkdir (fn, mode) == -1 && errno != EEXIST)
{
int errno_save = errno;
if (errno != ENOENT || !p)
{
g_free (fn);
errno = errno_save;
return -1;
}
}
}
else if (!g_file_test (fn, G_FILE_TEST_IS_DIR))
{
g_free (fn);
errno = ENOTDIR;
return -1;
}
if (p)
{
*p++ = G_DIR_SEPARATOR;
while (*p && G_IS_DIR_SEPARATOR (*p))
p++;
}
}
while (p);
g_free (fn);
return 0;
}
/**
* g_file_test:
* @filename: (type filename): a filename to test in the
* GLib file name encoding
* @test: bitfield of #GFileTest flags
*
* Returns %TRUE if any of the tests in the bitfield @test are
* %TRUE. For example, `(G_FILE_TEST_EXISTS | G_FILE_TEST_IS_DIR)`
* will return %TRUE if the file exists; the check whether it's a
* directory doesn't matter since the existence test is %TRUE. With
* the current set of available tests, there's no point passing in
* more than one test at a time.
*
* Apart from %G_FILE_TEST_IS_SYMLINK all tests follow symbolic links,
* so for a symbolic link to a regular file g_file_test() will return
* %TRUE for both %G_FILE_TEST_IS_SYMLINK and %G_FILE_TEST_IS_REGULAR.
*
* Note, that for a dangling symbolic link g_file_test() will return
* %TRUE for %G_FILE_TEST_IS_SYMLINK and %FALSE for all other flags.
*
* You should never use g_file_test() to test whether it is safe
* to perform an operation, because there is always the possibility
* of the condition changing before you actually perform the operation,
* see [TOCTOU](https://en.wikipedia.org/wiki/Time-of-check_to_time-of-use).
*
* For example, you might think you could use %G_FILE_TEST_IS_SYMLINK
* to know whether it is safe to write to a file without being
* tricked into writing into a different location. It doesn't work!
*
* |[<!-- language="C" -->
* // DON'T DO THIS
* if (!g_file_test (filename, G_FILE_TEST_IS_SYMLINK))
* {
* fd = g_open (filename, O_WRONLY);
* // write to fd
* }
*
* // DO THIS INSTEAD
* fd = g_open (filename, O_WRONLY | O_NOFOLLOW | O_CLOEXEC);
* if (fd == -1)
* {
* // check error
* if (errno == ELOOP)
* // file is a symlink and can be ignored
* else
* // handle errors as before
* }
* else
* {
* // write to fd
* }
* ]|
*
* Another thing to note is that %G_FILE_TEST_EXISTS and
* %G_FILE_TEST_IS_EXECUTABLE are implemented using the access()
* system call. This usually doesn't matter, but if your program
* is setuid or setgid it means that these tests will give you
* the answer for the real user ID and group ID, rather than the
* effective user ID and group ID.
*
* On Windows, there are no symlinks, so testing for
* %G_FILE_TEST_IS_SYMLINK will always return %FALSE. Testing for
* %G_FILE_TEST_IS_EXECUTABLE will just check that the file exists and
* its name indicates that it is executable, checking for well-known
* extensions and those listed in the `PATHEXT` environment variable.
*
* Returns: whether a test was %TRUE
**/
gboolean
g_file_test (const gchar *filename,
GFileTest test)
{
#ifdef G_OS_WIN32
DWORD attributes;
wchar_t *wfilename;
#endif
g_return_val_if_fail (filename != NULL, FALSE);
#ifdef G_OS_WIN32
/* stuff missing in std vc6 api */
# ifndef INVALID_FILE_ATTRIBUTES
# define INVALID_FILE_ATTRIBUTES -1
# endif
# ifndef FILE_ATTRIBUTE_DEVICE
# define FILE_ATTRIBUTE_DEVICE 64
# endif
wfilename = g_utf8_to_utf16 (filename, -1, NULL, NULL, NULL);
if (wfilename == NULL)
return FALSE;
attributes = GetFileAttributesW (wfilename);
g_free (wfilename);
if (attributes == INVALID_FILE_ATTRIBUTES)
return FALSE;
if (test & G_FILE_TEST_EXISTS)
return TRUE;
if (test & G_FILE_TEST_IS_REGULAR)
{
if ((attributes & (FILE_ATTRIBUTE_DIRECTORY | FILE_ATTRIBUTE_DEVICE)) == 0)
return TRUE;
}
if (test & G_FILE_TEST_IS_DIR)
{
if ((attributes & FILE_ATTRIBUTE_DIRECTORY) != 0)
return TRUE;
}
/* "while" so that we can exit this "loop" with a simple "break" */
while (test & G_FILE_TEST_IS_EXECUTABLE)
{
const gchar *lastdot = strrchr (filename, '.');
const gchar *pathext = NULL, *p;
int extlen;
if (lastdot == NULL)
break;
if (_stricmp (lastdot, ".exe") == 0 ||
_stricmp (lastdot, ".cmd") == 0 ||
_stricmp (lastdot, ".bat") == 0 ||
_stricmp (lastdot, ".com") == 0)
return TRUE;
/* Check if it is one of the types listed in %PATHEXT% */
pathext = g_getenv ("PATHEXT");
if (pathext == NULL)
break;
pathext = g_utf8_casefold (pathext, -1);
lastdot = g_utf8_casefold (lastdot, -1);
extlen = strlen (lastdot);
p = pathext;
while (TRUE)
{
const gchar *q = strchr (p, ';');
if (q == NULL)
q = p + strlen (p);
if (extlen == q - p &&
memcmp (lastdot, p, extlen) == 0)
{
g_free ((gchar *) pathext);
g_free ((gchar *) lastdot);
return TRUE;
}
if (*q)
p = q + 1;
else
break;
}
g_free ((gchar *) pathext);
g_free ((gchar *) lastdot);
break;
}
return FALSE;
#else
if ((test & G_FILE_TEST_EXISTS) && (access (filename, F_OK) == 0))
return TRUE;
if ((test & G_FILE_TEST_IS_EXECUTABLE) && (access (filename, X_OK) == 0))
{
if (getuid () != 0)
return TRUE;
/* For root, on some POSIX systems, access (filename, X_OK)
* will succeed even if no executable bits are set on the
* file. We fall through to a stat test to avoid that.
*/
}
else
test &= ~G_FILE_TEST_IS_EXECUTABLE;
if (test & G_FILE_TEST_IS_SYMLINK)
{
struct stat s;
if ((lstat (filename, &s) == 0) && S_ISLNK (s.st_mode))
return TRUE;
}
if (test & (G_FILE_TEST_IS_REGULAR |
G_FILE_TEST_IS_DIR |
G_FILE_TEST_IS_EXECUTABLE))
{
struct stat s;
if (stat (filename, &s) == 0)
{
if ((test & G_FILE_TEST_IS_REGULAR) && S_ISREG (s.st_mode))
return TRUE;
if ((test & G_FILE_TEST_IS_DIR) && S_ISDIR (s.st_mode))
return TRUE;
/* The extra test for root when access (file, X_OK) succeeds.
*/
if ((test & G_FILE_TEST_IS_EXECUTABLE) &&
((s.st_mode & S_IXOTH) ||
(s.st_mode & S_IXUSR) ||
(s.st_mode & S_IXGRP)))
return TRUE;
}
}
return FALSE;
#endif
}
G_DEFINE_QUARK (g-file-error-quark, g_file_error)
/**
* g_file_error_from_errno:
* @err_no: an "errno" value
*
* Gets a #GFileError constant based on the passed-in @err_no.
*
* For example, if you pass in `EEXIST` this function returns
* %G_FILE_ERROR_EXIST. Unlike `errno` values, you can portably
* assume that all #GFileError values will exist.
*
* Normally a #GFileError value goes into a #GError returned
* from a function that manipulates files. So you would use
* g_file_error_from_errno() when constructing a #GError.
*
* Returns: #GFileError corresponding to the given @err_no
**/
GFileError
g_file_error_from_errno (gint err_no)
{
switch (err_no)
{
#ifdef EEXIST
case EEXIST:
return G_FILE_ERROR_EXIST;
#endif
#ifdef EISDIR
case EISDIR:
return G_FILE_ERROR_ISDIR;
#endif
#ifdef EACCES
case EACCES:
return G_FILE_ERROR_ACCES;
#endif
#ifdef ENAMETOOLONG
case ENAMETOOLONG:
return G_FILE_ERROR_NAMETOOLONG;
#endif
#ifdef ENOENT
case ENOENT:
return G_FILE_ERROR_NOENT;
#endif
#ifdef ENOTDIR
case ENOTDIR:
return G_FILE_ERROR_NOTDIR;
#endif
#ifdef ENXIO
case ENXIO:
return G_FILE_ERROR_NXIO;
#endif
#ifdef ENODEV
case ENODEV:
return G_FILE_ERROR_NODEV;
#endif
#ifdef EROFS
case EROFS:
return G_FILE_ERROR_ROFS;
#endif
#ifdef ETXTBSY
case ETXTBSY:
return G_FILE_ERROR_TXTBSY;
#endif
#ifdef EFAULT
case EFAULT:
return G_FILE_ERROR_FAULT;
#endif
#ifdef ELOOP
case ELOOP:
return G_FILE_ERROR_LOOP;
#endif
#ifdef ENOSPC
case ENOSPC:
return G_FILE_ERROR_NOSPC;
#endif
#ifdef ENOMEM
case ENOMEM:
return G_FILE_ERROR_NOMEM;
#endif
#ifdef EMFILE
case EMFILE:
return G_FILE_ERROR_MFILE;
#endif
#ifdef ENFILE
case ENFILE:
return G_FILE_ERROR_NFILE;
#endif
#ifdef EBADF
case EBADF:
return G_FILE_ERROR_BADF;
#endif
#ifdef EINVAL
case EINVAL:
return G_FILE_ERROR_INVAL;
#endif
#ifdef EPIPE
case EPIPE:
return G_FILE_ERROR_PIPE;
#endif
#ifdef EAGAIN
case EAGAIN:
return G_FILE_ERROR_AGAIN;
#endif
#ifdef EINTR
case EINTR:
return G_FILE_ERROR_INTR;
#endif
#ifdef EIO
case EIO:
return G_FILE_ERROR_IO;
#endif
#ifdef EPERM
case EPERM:
return G_FILE_ERROR_PERM;
#endif
#ifdef ENOSYS
case ENOSYS:
return G_FILE_ERROR_NOSYS;
#endif
default:
return G_FILE_ERROR_FAILED;
}
}
static char *
format_error_message (const gchar *filename,
const gchar *format_string,
int saved_errno) G_GNUC_FORMAT(2);
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wformat-nonliteral"
static char *
format_error_message (const gchar *filename,
const gchar *format_string,
int saved_errno)
{
gchar *display_name;
gchar *msg;
display_name = g_filename_display_name (filename);
msg = g_strdup_printf (format_string, display_name, g_strerror (saved_errno));
g_free (display_name);
return msg;
}
#pragma GCC diagnostic pop
/* format string must have two '%s':
*
* - the place for the filename
* - the place for the strerror
*/
static void
set_file_error (GError **error,
const gchar *filename,
const gchar *format_string,
int saved_errno)
{
char *msg = format_error_message (filename, format_string, saved_errno);
g_set_error_literal (error, G_FILE_ERROR, g_file_error_from_errno (saved_errno),
msg);
g_free (msg);
}
static gboolean
get_contents_stdio (const gchar *filename,
FILE *f,
gchar **contents,
gsize *length,
GError **error)
{
gchar buf[4096];
gsize bytes; /* always <= sizeof(buf) */
gchar *str = NULL;
gsize total_bytes = 0;
gsize total_allocated = 0;
gchar *tmp;
gchar *display_filename;
g_assert (f != NULL);
while (!feof (f))
{
gint save_errno;
bytes = fread (buf, 1, sizeof (buf), f);
save_errno = errno;
if (total_bytes > G_MAXSIZE - bytes)
goto file_too_large;
/* Possibility of overflow eliminated above. */
while (total_bytes + bytes >= total_allocated)
{
if (str)
{
if (total_allocated > G_MAXSIZE / 2)
goto file_too_large;
total_allocated *= 2;
}
else
{
total_allocated = MIN (bytes + 1, sizeof (buf));
}
tmp = g_try_realloc (str, total_allocated);
if (tmp == NULL)
{
display_filename = g_filename_display_name (filename);
g_set_error (error,
G_FILE_ERROR,
G_FILE_ERROR_NOMEM,
g_dngettext (GETTEXT_PACKAGE, "Could not allocate %lu byte to read file “%s”", "Could not allocate %lu bytes to read file “%s”", (gulong)total_allocated),
(gulong) total_allocated,
display_filename);
g_free (display_filename);
goto error;
}
str = tmp;
}
if (ferror (f))
{
display_filename = g_filename_display_name (filename);
g_set_error (error,
G_FILE_ERROR,
g_file_error_from_errno (save_errno),
_("Error reading file “%s”: %s"),
display_filename,
g_strerror (save_errno));
g_free (display_filename);
goto error;
}
g_assert (str != NULL);
memcpy (str + total_bytes, buf, bytes);
total_bytes += bytes;
}
fclose (f);
if (total_allocated == 0)
{
str = g_new (gchar, 1);
total_bytes = 0;
}
str[total_bytes] = '\0';
if (length)
*length = total_bytes;
*contents = str;
return TRUE;
file_too_large:
display_filename = g_filename_display_name (filename);
g_set_error (error,
G_FILE_ERROR,
G_FILE_ERROR_FAILED,
_("File “%s” is too large"),
display_filename);
g_free (display_filename);
error:
g_free (str);
fclose (f);
return FALSE;
}
#ifndef G_OS_WIN32
static gboolean
get_contents_regfile (const gchar *filename,
struct stat *stat_buf,
gint fd,
gchar **contents,
gsize *length,
GError **error)
{
gchar *buf;
gsize bytes_read;
gsize size;
gsize alloc_size;
gchar *display_filename;
size = stat_buf->st_size;
alloc_size = size + 1;
buf = g_try_malloc (alloc_size);
if (buf == NULL)
{
display_filename = g_filename_display_name (filename);
g_set_error (error,
G_FILE_ERROR,
G_FILE_ERROR_NOMEM,
g_dngettext (GETTEXT_PACKAGE, "Could not allocate %lu byte to read file “%s”", "Could not allocate %lu bytes to read file “%s”", (gulong)alloc_size),
(gulong) alloc_size,
display_filename);
g_free (display_filename);
goto error;
}
bytes_read = 0;
while (bytes_read < size)
{
gssize rc;
rc = read (fd, buf + bytes_read, size - bytes_read);
if (rc < 0)
{
if (errno != EINTR)
{
int save_errno = errno;
g_free (buf);
display_filename = g_filename_display_name (filename);
g_set_error (error,
G_FILE_ERROR,
g_file_error_from_errno (save_errno),
_("Failed to read from file “%s”: %s"),
display_filename,
g_strerror (save_errno));
g_free (display_filename);
goto error;
}
}
else if (rc == 0)
break;
else
bytes_read += rc;
}
buf[bytes_read] = '\0';
if (length)
*length = bytes_read;
*contents = buf;
close (fd);
return TRUE;
error:
close (fd);
return FALSE;
}
static gboolean
get_contents_posix (const gchar *filename,
gchar **contents,
gsize *length,
GError **error)
{
struct stat stat_buf;
gint fd;
/* O_BINARY useful on Cygwin */
fd = open (filename, O_RDONLY | O_BINARY | O_CLOEXEC);
if (fd < 0)
{
int saved_errno = errno;
if (error)
set_file_error (error,
filename,
_("Failed to open file “%s”: %s"),
saved_errno);
return FALSE;
}
/* I don't think this will ever fail, aside from ENOMEM, but. */
if (fstat (fd, &stat_buf) < 0)
{
int saved_errno = errno;
if (error)
set_file_error (error,
filename,
_("Failed to get attributes of file “%s”: fstat() failed: %s"),
saved_errno);
close (fd);
return FALSE;
}
if (stat_buf.st_size > 0 && S_ISREG (stat_buf.st_mode))
{
gboolean retval = get_contents_regfile (filename,
&stat_buf,
fd,
contents,
length,
error);
return retval;
}
else
{
FILE *f;
gboolean retval;
f = fdopen (fd, "r");
if (f == NULL)
{
int saved_errno = errno;
if (error)
set_file_error (error,
filename,
_("Failed to open file “%s”: fdopen() failed: %s"),
saved_errno);
return FALSE;
}
retval = get_contents_stdio (filename, f, contents, length, error);
return retval;
}
}
#else /* G_OS_WIN32 */
static gboolean
get_contents_win32 (const gchar *filename,
gchar **contents,
gsize *length,
GError **error)
{
FILE *f;
gboolean retval;
f = g_fopen (filename, "rb");
if (f == NULL)
{
int saved_errno = errno;
if (error)
set_file_error (error,
filename,
_("Failed to open file “%s”: %s"),
saved_errno);
return FALSE;
}
retval = get_contents_stdio (filename, f, contents, length, error);
return retval;
}
#endif
/**
* g_file_get_contents:
* @filename: (type filename): name of a file to read contents from, in the GLib file name encoding
* @contents: (out) (array length=length) (element-type guint8): location to store an allocated string, use g_free() to free
* the returned string
* @length: (nullable): location to store length in bytes of the contents, or %NULL
* @error: return location for a #GError, or %NULL
*
* Reads an entire file into allocated memory, with good error
* checking.
*
* If the call was successful, it returns %TRUE and sets @contents to the file
* contents and @length to the length of the file contents in bytes. The string
* stored in @contents will be nul-terminated, so for text files you can pass
* %NULL for the @length argument. If the call was not successful, it returns
* %FALSE and sets @error. The error domain is %G_FILE_ERROR. Possible error
* codes are those in the #GFileError enumeration. In the error case,
* @contents is set to %NULL and @length is set to zero.
*
* Returns: %TRUE on success, %FALSE if an error occurred
**/
gboolean
g_file_get_contents (const gchar *filename,
gchar **contents,
gsize *length,
GError **error)
{
g_return_val_if_fail (filename != NULL, FALSE);
g_return_val_if_fail (contents != NULL, FALSE);
*contents = NULL;
if (length)
*length = 0;
#ifdef G_OS_WIN32
return get_contents_win32 (filename, contents, length, error);
#else
return get_contents_posix (filename, contents, length, error);
#endif
}
static gboolean
rename_file (const char *old_name,
const char *new_name,
gboolean do_fsync,
GError **err)
{
errno = 0;
if (g_rename (old_name, new_name) == -1)
{
int save_errno = errno;
gchar *display_old_name = g_filename_display_name (old_name);
gchar *display_new_name = g_filename_display_name (new_name);
g_set_error (err,
G_FILE_ERROR,
g_file_error_from_errno (save_errno),
_("Failed to rename file “%s” to “%s”: g_rename() failed: %s"),
display_old_name,
display_new_name,
g_strerror (save_errno));
g_free (display_old_name);
g_free (display_new_name);
return FALSE;
}
/* In order to guarantee that the *new* contents of the file are seen in
* future, fsync() the directory containing the file. Otherwise if the file
* system was unmounted cleanly now, it would be undefined whether the old
* or new contents of the file were visible after recovery.
*
* This assumes the @old_name and @new_name are in the same directory. */
#ifdef HAVE_FSYNC
if (do_fsync)
{
gchar *dir = g_path_get_dirname (new_name);
int dir_fd = g_open (dir, O_RDONLY | O_CLOEXEC, 0);
if (dir_fd >= 0)
{
g_fsync (dir_fd);
g_close (dir_fd, NULL);
}
g_free (dir);
}
#endif /* HAVE_FSYNC */
return TRUE;
}
static gboolean
fd_should_be_fsynced (int fd,
const gchar *test_file,
GFileSetContentsFlags flags)
{
#ifdef HAVE_FSYNC
struct stat statbuf;
/* If the final destination exists and is > 0 bytes, we want to sync the
* newly written file to ensure the data is on disk when we rename over
* the destination. Otherwise if we get a system crash we can lose both
* the new and the old file on some filesystems. (I.E. those that don't
* guarantee the data is written to the disk before the metadata.)
*
* There is no difference (in file system terms) if the old file doesn’t
* already exist, apart from the fact that if the system crashes and the new
* data hasn’t been fsync()ed, there is only one bit of old data to lose (that
* the file didn’t exist in the first place). In some situations, such as
* trashing files, the old file never exists, so it seems reasonable to avoid
* the fsync(). This is not a widely applicable optimisation though.
*/
if ((flags & (G_FILE_SET_CONTENTS_CONSISTENT | G_FILE_SET_CONTENTS_DURABLE)) &&
(flags & G_FILE_SET_CONTENTS_ONLY_EXISTING))
{
errno = 0;
if (g_lstat (test_file, &statbuf) == 0)
return (statbuf.st_size > 0);
else if (errno == ENOENT)
return FALSE;
else
return TRUE; /* lstat() failed; be cautious */
}
else
{
return (flags & (G_FILE_SET_CONTENTS_CONSISTENT | G_FILE_SET_CONTENTS_DURABLE));
}
#else /* if !HAVE_FSYNC */
return FALSE;
#endif /* !HAVE_FSYNC */
}
/* closes @fd once it’s finished (on success or error) */
static gboolean
write_to_file (const gchar *contents,
gsize length,
int fd,
const gchar *dest_file,
gboolean do_fsync,
GError **err)
{
#ifdef HAVE_FALLOCATE
if (length > 0)
{
/* We do this on a 'best effort' basis... It may not be supported
* on the underlying filesystem.
*/
(void) fallocate (fd, 0, 0, length);
}
#endif
while (length > 0)
{
gssize s;
#ifdef G_OS_WIN32
/* 'write' on windows uses int types, so limit count to G_MAXINT */
s = write (fd, contents, MIN (length, (gsize) G_MAXINT));
#else
/* Limit count to G_MAXSSIZE to fit into the return value. */
s = write (fd, contents, MIN (length, (gsize) G_MAXSSIZE));
#endif
if (s < 0)
{
int saved_errno = errno;
if (saved_errno == EINTR)
continue;
if (err)
set_file_error (err,
dest_file, _("Failed to write file “%s”: write() failed: %s"),
saved_errno);
close (fd);
return FALSE;
}
g_assert ((gsize) s <= length);
contents += s;
length -= s;
}
#ifdef HAVE_FSYNC
errno = 0;
if (do_fsync && g_fsync (fd) != 0)
{
int saved_errno = errno;
if (err)
set_file_error (err,
dest_file, _("Failed to write file “%s”: fsync() failed: %s"),
saved_errno);
close (fd);
return FALSE;
}
#endif
errno = 0;
if (!g_close (fd, err))
return FALSE;
return TRUE;
}
/**
* g_file_set_contents:
* @filename: (type filename): name of a file to write @contents to, in the GLib file name
* encoding
* @contents: (array length=length) (element-type guint8): string to write to the file
* @length: length of @contents, or -1 if @contents is a nul-terminated string
* @error: return location for a #GError, or %NULL
*
* Writes all of @contents to a file named @filename. This is a convenience
* wrapper around calling g_file_set_contents_full() with `flags` set to
* `G_FILE_SET_CONTENTS_CONSISTENT | G_FILE_SET_CONTENTS_ONLY_EXISTING` and
* `mode` set to `0666`.
*
* Returns: %TRUE on success, %FALSE if an error occurred
*
* Since: 2.8
*/
gboolean
g_file_set_contents (const gchar *filename,
const gchar *contents,
gssize length,
GError **error)
{
return g_file_set_contents_full (filename, contents, length,
G_FILE_SET_CONTENTS_CONSISTENT |
G_FILE_SET_CONTENTS_ONLY_EXISTING,
0666, error);
}
/**
* g_file_set_contents_full:
* @filename: (type filename): name of a file to write @contents to, in the GLib file name
* encoding
* @contents: (array length=length) (element-type guint8): string to write to the file
* @length: length of @contents, or -1 if @contents is a nul-terminated string
* @flags: flags controlling the safety vs speed of the operation
* @mode: file mode, as passed to `open()`; typically this will be `0666`
* @error: return location for a #GError, or %NULL
*
* Writes all of @contents to a file named @filename, with good error checking.
* If a file called @filename already exists it will be overwritten.
*
* @flags control the properties of the write operation: whether it’s atomic,
* and what the tradeoff is between returning quickly or being resilient to
* system crashes.
*
* As this function performs file I/O, it is recommended to not call it anywhere
* where blocking would cause problems, such as in the main loop of a graphical
* application. In particular, if @flags has any value other than
* %G_FILE_SET_CONTENTS_NONE then this function may call `fsync()`.
*
* If %G_FILE_SET_CONTENTS_CONSISTENT is set in @flags, the operation is atomic
* in the sense that it is first written to a temporary file which is then
* renamed to the final name.
*
* Notes:
*
* - On UNIX, if @filename already exists hard links to @filename will break.
* Also since the file is recreated, existing permissions, access control
* lists, metadata etc. may be lost. If @filename is a symbolic link,
* the link itself will be replaced, not the linked file.
*
* - On UNIX, if @filename already exists and is non-empty, and if the system
* supports it (via a journalling filesystem or equivalent), and if
* %G_FILE_SET_CONTENTS_CONSISTENT is set in @flags, the `fsync()` call (or
* equivalent) will be used to ensure atomic replacement: @filename
* will contain either its old contents or @contents, even in the face of
* system power loss, the disk being unsafely removed, etc.
*
* - On UNIX, if @filename does not already exist or is empty, there is a
* possibility that system power loss etc. after calling this function will
* leave @filename empty or full of NUL bytes, depending on the underlying
* filesystem, unless %G_FILE_SET_CONTENTS_DURABLE and
* %G_FILE_SET_CONTENTS_CONSISTENT are set in @flags.
*
* - On Windows renaming a file will not remove an existing file with the
* new name, so on Windows there is a race condition between the existing
* file being removed and the temporary file being renamed.
*
* - On Windows there is no way to remove a file that is open to some
* process, or mapped into memory. Thus, this function will fail if
* @filename already exists and is open.
*
* If the call was successful, it returns %TRUE. If the call was not successful,
* it returns %FALSE and sets @error. The error domain is %G_FILE_ERROR.
* Possible error codes are those in the #GFileError enumeration.
*
* Note that the name for the temporary file is constructed by appending up
* to 7 characters to @filename.
*
* If the file didn’t exist before and is created, it will be given the
* permissions from @mode. Otherwise, the permissions of the existing file may
* be changed to @mode depending on @flags, or they may remain unchanged.
*
* Returns: %TRUE on success, %FALSE if an error occurred
*
* Since: 2.66
*/
gboolean
g_file_set_contents_full (const gchar *filename,
const gchar *contents,
gssize length,
GFileSetContentsFlags flags,
int mode,
GError **error)
{
g_return_val_if_fail (filename != NULL, FALSE);
g_return_val_if_fail (error == NULL || *error == NULL, FALSE);
g_return_val_if_fail (contents != NULL || length == 0, FALSE);
g_return_val_if_fail (length >= -1, FALSE);
/* @flags are handled as follows:
* - %G_FILE_SET_CONTENTS_NONE: write directly to @filename, no fsync()s
* - %G_FILE_SET_CONTENTS_CONSISTENT: write to temp file, fsync() it, rename()
* - %G_FILE_SET_CONTENTS_CONSISTENT | ONLY_EXISTING: as above, but skip the
* fsync() if @filename doesn’t exist or is empty
* - %G_FILE_SET_CONTENTS_DURABLE: write directly to @filename, fsync() it
* - %G_FILE_SET_CONTENTS_DURABLE | ONLY_EXISTING: as above, but skip the
* fsync() if @filename doesn’t exist or is empty
* - %G_FILE_SET_CONTENTS_CONSISTENT | DURABLE: write to temp file, fsync()
* it, rename(), fsync() containing directory
* - %G_FILE_SET_CONTENTS_CONSISTENT | DURABLE | ONLY_EXISTING: as above, but
* skip both fsync()s if @filename doesn’t exist or is empty
*/
if (length < 0)
length = strlen (contents);
if (flags & G_FILE_SET_CONTENTS_CONSISTENT)
{
gchar *tmp_filename = NULL;
GError *rename_error = NULL;
gboolean retval;
int fd;
gboolean do_fsync;
tmp_filename = g_strdup_printf ("%s.XXXXXX", filename);
errno = 0;
fd = g_mkstemp_full (tmp_filename, O_RDWR | O_BINARY | O_CLOEXEC, mode);
if (fd == -1)
{
int saved_errno = errno;
if (error)
set_file_error (error,
tmp_filename, _("Failed to create file “%s”: %s"),
saved_errno);
retval = FALSE;
goto consistent_out;
}
do_fsync = fd_should_be_fsynced (fd, filename, flags);
if (!write_to_file (contents, length, g_steal_fd (&fd), tmp_filename, do_fsync, error))
{
g_unlink (tmp_filename);
retval = FALSE;
goto consistent_out;
}
if (!rename_file (tmp_filename, filename, do_fsync, &rename_error))
{
#ifndef G_OS_WIN32
g_unlink (tmp_filename);
g_propagate_error (error, rename_error);
retval = FALSE;
goto consistent_out;
#else /* G_OS_WIN32 */
/* Renaming failed, but on Windows this may just mean
* the file already exists. So if the target file
* exists, try deleting it and do the rename again.
*/
if (!g_file_test (filename, G_FILE_TEST_EXISTS))
{
g_unlink (tmp_filename);
g_propagate_error (error, rename_error);
retval = FALSE;
goto consistent_out;
}
g_error_free (rename_error);
if (g_unlink (filename) == -1)
{
int saved_errno = errno;
if (error)
set_file_error (error,
filename,
_("Existing file “%s” could not be removed: g_unlink() failed: %s"),
saved_errno);
g_unlink (tmp_filename);
retval = FALSE;
goto consistent_out;
}
if (!rename_file (tmp_filename, filename, flags, error))
{
g_unlink (tmp_filename);
retval = FALSE;
goto consistent_out;
}
#endif /* G_OS_WIN32 */
}
retval = TRUE;
consistent_out:
g_free (tmp_filename);
return retval;
}
else
{
int direct_fd;
int open_flags;
gboolean do_fsync;
open_flags = O_RDWR | O_BINARY | O_CREAT | O_CLOEXEC;
#ifdef O_NOFOLLOW
/* Windows doesn’t have symlinks, so O_NOFOLLOW is unnecessary there. */
open_flags |= O_NOFOLLOW;
#endif
errno = 0;
direct_fd = g_open (filename, open_flags, mode);
if (direct_fd < 0)
{
int saved_errno = errno;
#ifdef O_NOFOLLOW
/* ELOOP indicates that @filename is a symlink, since we used
* O_NOFOLLOW (alternately it could indicate that @filename contains
* looping or too many symlinks). In either case, try again on the
* %G_FILE_SET_CONTENTS_CONSISTENT code path.
*
* FreeBSD uses EMLINK instead of ELOOP
* (https://www.freebsd.org/cgi/man.cgi?query=open&sektion=2#STANDARDS),
* and NetBSD uses EFTYPE
* (https://netbsd.gw.com/cgi-bin/man-cgi?open+2+NetBSD-current). */
#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__DragonFly__)
if (saved_errno == EMLINK)
#elif defined(__NetBSD__)
if (saved_errno == EFTYPE)
#else
if (saved_errno == ELOOP)
#endif
return g_file_set_contents_full (filename, contents, length,
flags | G_FILE_SET_CONTENTS_CONSISTENT,
mode, error);
#endif /* O_NOFOLLOW */
if (error)
set_file_error (error,
filename, _("Failed to open file “%s”: %s"),
saved_errno);
return FALSE;
}
do_fsync = fd_should_be_fsynced (direct_fd, filename, flags);
if (!write_to_file (contents, length, g_steal_fd (&direct_fd), filename,
do_fsync, error))
return FALSE;
}
return TRUE;
}
/*
* get_tmp_file based on the mkstemp implementation from the GNU C library.
* Copyright (C) 1991,92,93,94,95,96,97,98,99 Free Software Foundation, Inc.
*/
typedef gint (*GTmpFileCallback) (const gchar *, gint, gint);
static gint
get_tmp_file (gchar *tmpl,
GTmpFileCallback f,
int flags,
int mode)
{
char *XXXXXX;
int count, fd;
static const char letters[] =
"ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
static const int NLETTERS = sizeof (letters) - 1;
glong value;
gint64 now_us;
static int counter = 0;
g_return_val_if_fail (tmpl != NULL, -1);
/* find the last occurrence of "XXXXXX" */
XXXXXX = g_strrstr (tmpl, "XXXXXX");
if (!XXXXXX || strncmp (XXXXXX, "XXXXXX", 6))
{
errno = EINVAL;
return -1;
}
/* Get some more or less random data. */
now_us = g_get_real_time ();
value = ((now_us % G_USEC_PER_SEC) ^ (now_us / G_USEC_PER_SEC)) + counter++;
for (count = 0; count < 100; value += 7777, ++count)
{
glong v = value;
/* Fill in the random bits. */
XXXXXX[0] = letters[v % NLETTERS];
v /= NLETTERS;
XXXXXX[1] = letters[v % NLETTERS];
v /= NLETTERS;
XXXXXX[2] = letters[v % NLETTERS];
v /= NLETTERS;
XXXXXX[3] = letters[v % NLETTERS];
v /= NLETTERS;
XXXXXX[4] = letters[v % NLETTERS];
v /= NLETTERS;
XXXXXX[5] = letters[v % NLETTERS];
fd = f (tmpl, flags, mode);
if (fd >= 0)
return fd;
else if (errno != EEXIST)
/* Any other error will apply also to other names we might
* try, and there are 2^32 or so of them, so give up now.
*/
return -1;
}
/* We got out of the loop because we ran out of combinations to try. */
errno = EEXIST;
return -1;
}
/* Some GTmpFileCallback implementations.
*
* Note: we cannot use open() or g_open() directly because even though
* they appear compatible, they may be vararg functions and calling
* varargs functions through a non-varargs type is undefined.
*/
static gint
wrap_g_mkdir (const gchar *filename,
int flags G_GNUC_UNUSED,
int mode)
{
/* tmpl is in UTF-8 on Windows, thus use g_mkdir() */
return g_mkdir (filename, mode);
}
static gint
wrap_g_open (const gchar *filename,
int flags,
int mode)
{
return g_open (filename, flags, mode);
}
/**
* g_mkdtemp_full: (skip)
* @tmpl: (type filename): template directory name
* @mode: permissions to create the temporary directory with
*
* Creates a temporary directory. See the mkdtemp() documentation
* on most UNIX-like systems.
*
* The parameter is a string that should follow the rules for
* mkdtemp() templates, i.e. contain the string "XXXXXX".
* g_mkdtemp_full() is slightly more flexible than mkdtemp() in that the
* sequence does not have to occur at the very end of the template
* and you can pass a @mode. The X string will be modified to form
* the name of a directory that didn't exist. The string should be
* in the GLib file name encoding. Most importantly, on Windows it
* should be in UTF-8.
*
* If you are going to be creating a temporary directory inside the
* directory returned by g_get_tmp_dir(), you might want to use
* g_dir_make_tmp() instead.
*
* Returns: (nullable) (type filename): A pointer to @tmpl, which has been
* modified to hold the directory name. In case of errors, %NULL is
* returned, and %errno will be set.
*
* Since: 2.30
*/
gchar *
g_mkdtemp_full (gchar *tmpl,
gint mode)
{
if (get_tmp_file (tmpl, wrap_g_mkdir, 0, mode) == -1)
return NULL;
else
return tmpl;
}
/**
* g_mkdtemp: (skip)
* @tmpl: (type filename): template directory name
*
* Creates a temporary directory. See the mkdtemp() documentation
* on most UNIX-like systems.
*
* The parameter is a string that should follow the rules for
* mkdtemp() templates, i.e. contain the string "XXXXXX".
* g_mkdtemp() is slightly more flexible than mkdtemp() in that the
* sequence does not have to occur at the very end of the template.
* The X string will be modified to form the name of a directory that
* didn't exist.
* The string should be in the GLib file name encoding. Most importantly,
* on Windows it should be in UTF-8.
*
* If you are going to be creating a temporary directory inside the
* directory returned by g_get_tmp_dir(), you might want to use
* g_dir_make_tmp() instead.
*
* Returns: (nullable) (type filename): A pointer to @tmpl, which has been
* modified to hold the directory name. In case of errors, %NULL is
* returned and %errno will be set.
*
* Since: 2.30
*/
gchar *
g_mkdtemp (gchar *tmpl)
{
return g_mkdtemp_full (tmpl, 0700);
}
/**
* g_mkstemp_full: (skip)
* @tmpl: (type filename): template filename
* @flags: flags to pass to an open() call in addition to O_EXCL
* and O_CREAT, which are passed automatically
* @mode: permissions to create the temporary file with
*
* Opens a temporary file. See the mkstemp() documentation
* on most UNIX-like systems.
*
* The parameter is a string that should follow the rules for
* mkstemp() templates, i.e. contain the string "XXXXXX".
* g_mkstemp_full() is slightly more flexible than mkstemp()
* in that the sequence does not have to occur at the very end of the
* template and you can pass a @mode and additional @flags. The X
* string will be modified to form the name of a file that didn't exist.
* The string should be in the GLib file name encoding. Most importantly,
* on Windows it should be in UTF-8.
*
* Returns: A file handle (as from open()) to the file
* opened for reading and writing. The file handle should be
* closed with close(). In case of errors, -1 is returned
* and %errno will be set.
*
* Since: 2.22
*/
gint
g_mkstemp_full (gchar *tmpl,
gint flags,
gint mode)
{
/* tmpl is in UTF-8 on Windows, thus use g_open() */
return get_tmp_file (tmpl, wrap_g_open,
flags | O_CREAT | O_EXCL, mode);
}
/**
* g_mkstemp: (skip)
* @tmpl: (type filename): template filename
*
* Opens a temporary file. See the mkstemp() documentation
* on most UNIX-like systems.
*
* The parameter is a string that should follow the rules for
* mkstemp() templates, i.e. contain the string "XXXXXX".
* g_mkstemp() is slightly more flexible than mkstemp() in that the
* sequence does not have to occur at the very end of the template.
* The X string will be modified to form the name of a file that
* didn't exist. The string should be in the GLib file name encoding.
* Most importantly, on Windows it should be in UTF-8.
*
* Returns: A file handle (as from open()) to the file
* opened for reading and writing. The file is opened in binary
* mode on platforms where there is a difference. The file handle
* should be closed with close(). In case of errors, -1 is
* returned and %errno will be set.
*/
gint
g_mkstemp (gchar *tmpl)
{
return g_mkstemp_full (tmpl, O_RDWR | O_BINARY | O_CLOEXEC, 0600);
}
static gint
g_get_tmp_name (const gchar *tmpl,
gchar **name_used,
GTmpFileCallback f,
gint flags,
gint mode,
GError **error)
{
int retval;
const char *tmpdir;
const char *sep;
char *fulltemplate;
const char *slash;
if (tmpl == NULL)
tmpl = ".XXXXXX";
if ((slash = strchr (tmpl, G_DIR_SEPARATOR)) != NULL
#ifdef G_OS_WIN32
|| (strchr (tmpl, '/') != NULL && (slash = "/"))
#endif
)
{
gchar *display_tmpl = g_filename_display_name (tmpl);
char c[2];
c[0] = *slash;
c[1] = '\0';
g_set_error (error,
G_FILE_ERROR,
G_FILE_ERROR_FAILED,
_("Template “%s” invalid, should not contain a “%s”"),
display_tmpl, c);
g_free (display_tmpl);
return -1;
}
if (strstr (tmpl, "XXXXXX") == NULL)
{
gchar *display_tmpl = g_filename_display_name (tmpl);
g_set_error (error,
G_FILE_ERROR,
G_FILE_ERROR_FAILED,
_("Template “%s” doesn’t contain XXXXXX"),
display_tmpl);
g_free (display_tmpl);
return -1;
}
tmpdir = g_get_tmp_dir ();
if (G_IS_DIR_SEPARATOR (tmpdir [strlen (tmpdir) - 1]))
sep = "";
else
sep = G_DIR_SEPARATOR_S;
fulltemplate = g_strconcat (tmpdir, sep, tmpl, NULL);
retval = get_tmp_file (fulltemplate, f, flags, mode);
if (retval == -1)
{
int saved_errno = errno;
if (error)
set_file_error (error,
fulltemplate,
_("Failed to create file “%s”: %s"),
saved_errno);
g_free (fulltemplate);
return -1;
}
*name_used = fulltemplate;
return retval;
}
/**
* g_file_open_tmp:
* @tmpl: (type filename) (nullable): Template for file name, as in
* g_mkstemp(), basename only, or %NULL for a default template
* @name_used: (out) (type filename): location to store actual name used,
* or %NULL
* @error: return location for a #GError
*
* Opens a file for writing in the preferred directory for temporary
* files (as returned by g_get_tmp_dir()).
*
* @tmpl should be a string in the GLib file name encoding containing
* a sequence of six 'X' characters, as the parameter to g_mkstemp().
* However, unlike these functions, the template should only be a
* basename, no directory components are allowed. If template is
* %NULL, a default template is used.
*
* Note that in contrast to g_mkstemp() (and mkstemp()) @tmpl is not
* modified, and might thus be a read-only literal string.
*
* Upon success, and if @name_used is non-%NULL, the actual name used
* is returned in @name_used. This string should be freed with g_free()
* when not needed any longer. The returned name is in the GLib file
* name encoding.
*
* Returns: A file handle (as from open()) to the file opened for
* reading and writing. The file is opened in binary mode on platforms
* where there is a difference. The file handle should be closed with
* close(). In case of errors, -1 is returned and @error will be set.
*/
gint
g_file_open_tmp (const gchar *tmpl,
gchar **name_used,
GError **error)
{
gchar *fulltemplate;
gint result;
g_return_val_if_fail (error == NULL || *error == NULL, -1);
result = g_get_tmp_name (tmpl, &fulltemplate,
wrap_g_open,
O_CREAT | O_EXCL | O_RDWR | O_BINARY | O_CLOEXEC,
0600,
error);
if (result != -1)
{
if (name_used)
*name_used = fulltemplate;
else
g_free (fulltemplate);
}
return result;
}
/**
* g_dir_make_tmp:
* @tmpl: (type filename) (nullable): Template for directory name,
* as in g_mkdtemp(), basename only, or %NULL for a default template
* @error: return location for a #GError
*
* Creates a subdirectory in the preferred directory for temporary
* files (as returned by g_get_tmp_dir()).
*
* @tmpl should be a string in the GLib file name encoding containing
* a sequence of six 'X' characters, as the parameter to g_mkstemp().
* However, unlike these functions, the template should only be a
* basename, no directory components are allowed. If template is
* %NULL, a default template is used.
*
* Note that in contrast to g_mkdtemp() (and mkdtemp()) @tmpl is not
* modified, and might thus be a read-only literal string.
*
* Returns: (type filename) (transfer full): The actual name used. This string
* should be freed with g_free() when not needed any longer and is
* is in the GLib file name encoding. In case of errors, %NULL is
* returned and @error will be set.
*
* Since: 2.30
*/
gchar *
g_dir_make_tmp (const gchar *tmpl,
GError **error)
{
gchar *fulltemplate;
g_return_val_if_fail (error == NULL || *error == NULL, NULL);
if (g_get_tmp_name (tmpl, &fulltemplate, wrap_g_mkdir, 0, 0700, error) == -1)
return NULL;
else
return fulltemplate;
}
static gchar *
g_build_path_va (const gchar *separator,
const gchar *first_element,
va_list *args,
gchar **str_array)
{
GString *result;
gint separator_len = strlen (separator);
gboolean is_first = TRUE;
gboolean have_leading = FALSE;
const gchar *single_element = NULL;
const gchar *next_element;
const gchar *last_trailing = NULL;
gint i = 0;
result = g_string_new (NULL);
if (str_array)
next_element = str_array[i++];
else
next_element = first_element;
while (TRUE)
{
const gchar *element;
const gchar *start;
const gchar *end;
if (next_element)
{
element = next_element;
if (str_array)
next_element = str_array[i++];
else
next_element = va_arg (*args, gchar *);
}
else
break;
/* Ignore empty elements */
if (!*element)
continue;
start = element;
if (separator_len)
{
while (strncmp (start, separator, separator_len) == 0)
start += separator_len;
}
end = start + strlen (start);
if (separator_len)
{
while (end >= start + separator_len &&
strncmp (end - separator_len, separator, separator_len) == 0)
end -= separator_len;
last_trailing = end;
while (last_trailing >= element + separator_len &&
strncmp (last_trailing - separator_len, separator, separator_len) == 0)
last_trailing -= separator_len;
if (!have_leading)
{
/* If the leading and trailing separator strings are in the
* same element and overlap, the result is exactly that element
*/
if (last_trailing <= start)
single_element = element;
g_string_append_len (result, element, start - element);
have_leading = TRUE;
}
else
single_element = NULL;
}
if (end == start)
continue;
if (!is_first)
g_string_append (result, separator);
g_string_append_len (result, start, end - start);
is_first = FALSE;
}
if (single_element)
{
g_string_free (result, TRUE);
return g_strdup (single_element);
}
else
{
if (last_trailing)
g_string_append (result, last_trailing);
return g_string_free (result, FALSE);
}
}
/**
* g_build_pathv:
* @separator: a string used to separator the elements of the path.
* @args: (array zero-terminated=1) (element-type filename): %NULL-terminated
* array of strings containing the path elements.
*
* Behaves exactly like g_build_path(), but takes the path elements
* as a string array, instead of variadic arguments.
*
* This function is mainly meant for language bindings.
*
* Returns: (type filename) (transfer full): a newly-allocated string that
* must be freed with g_free().
*
* Since: 2.8
*/
gchar *
g_build_pathv (const gchar *separator,
gchar **args)
{
if (!args)
return NULL;
return g_build_path_va (separator, NULL, NULL, args);
}
/**
* g_build_path:
* @separator: (type filename): a string used to separator the elements of the path.
* @first_element: (type filename): the first element in the path
* @...: remaining elements in path, terminated by %NULL
*
* Creates a path from a series of elements using @separator as the
* separator between elements.
*
* At the boundary between two elements, any trailing occurrences of
* separator in the first element, or leading occurrences of separator
* in the second element are removed and exactly one copy of the
* separator is inserted.
*
* Empty elements are ignored.
*
* The number of leading copies of the separator on the result is
* the same as the number of leading copies of the separator on
* the first non-empty element.
*
* The number of trailing copies of the separator on the result is
* the same as the number of trailing copies of the separator on
* the last non-empty element. (Determination of the number of
* trailing copies is done without stripping leading copies, so
* if the separator is `ABA`, then `ABABA` has 1 trailing copy.)
*
* However, if there is only a single non-empty element, and there
* are no characters in that element not part of the leading or
* trailing separators, then the result is exactly the original value
* of that element.
*
* Other than for determination of the number of leading and trailing
* copies of the separator, elements consisting only of copies
* of the separator are ignored.
*
* Returns: (type filename) (transfer full): the newly allocated path
**/
gchar *
g_build_path (const gchar *separator,
const gchar *first_element,
...)
{
gchar *str;
va_list args;
g_return_val_if_fail (separator != NULL, NULL);
va_start (args, first_element);
str = g_build_path_va (separator, first_element, &args, NULL);
va_end (args);
return str;
}
#ifdef G_OS_WIN32
static gchar *
g_build_pathname_va (const gchar *first_element,
va_list *args,
gchar **str_array)
{
/* Code copied from g_build_pathv(), and modified to use two
* alternative single-character separators.
*/
GString *result;
gboolean is_first = TRUE;
gboolean have_leading = FALSE;
const gchar *single_element = NULL;
const gchar *next_element;
const gchar *last_trailing = NULL;
gchar current_separator = '\\';
gint i = 0;
result = g_string_new (NULL);
if (str_array)
next_element = str_array[i++];
else
next_element = first_element;
while (TRUE)
{
const gchar *element;
const gchar *start;
const gchar *end;
if (next_element)
{
element = next_element;
if (str_array)
next_element = str_array[i++];
else
next_element = va_arg (*args, gchar *);
}
else
break;
/* Ignore empty elements */
if (!*element)
continue;
start = element;
if (TRUE)
{
while (start &&
(*start == '\\' || *start == '/'))
{
current_separator = *start;
start++;
}
}
end = start + strlen (start);
if (TRUE)
{
while (end >= start + 1 &&
(end[-1] == '\\' || end[-1] == '/'))
{
current_separator = end[-1];
end--;
}
last_trailing = end;
while (last_trailing >= element + 1 &&
(last_trailing[-1] == '\\' || last_trailing[-1] == '/'))
last_trailing--;
if (!have_leading)
{
/* If the leading and trailing separator strings are in the
* same element and overlap, the result is exactly that element
*/
if (last_trailing <= start)
single_element = element;
g_string_append_len (result, element, start - element);
have_leading = TRUE;
}
else
single_element = NULL;
}
if (end == start)
continue;
if (!is_first)
g_string_append_len (result, &current_separator, 1);
g_string_append_len (result, start, end - start);
is_first = FALSE;
}
if (single_element)
{
g_string_free (result, TRUE);
return g_strdup (single_element);
}
else
{
if (last_trailing)
g_string_append (result, last_trailing);
return g_string_free (result, FALSE);
}
}
#endif
static gchar *
g_build_filename_va (const gchar *first_argument,
va_list *args,
gchar **str_array)
{
gchar *str;
#ifndef G_OS_WIN32
str = g_build_path_va (G_DIR_SEPARATOR_S, first_argument, args, str_array);
#else
str = g_build_pathname_va (first_argument, args, str_array);
#endif
return str;
}
/**
* g_build_filename_valist:
* @first_element: (type filename): the first element in the path
* @args: va_list of remaining elements in path
*
* Creates a filename from a list of elements using the correct
* separator for the current platform.
*
* Behaves exactly like g_build_filename(), but takes the path elements
* as a va_list.
*
* This function is mainly meant for implementing other variadic arguments
* functions.
*
* Returns: (type filename) (transfer full): the newly allocated path
*
* Since: 2.56
*/
gchar *
g_build_filename_valist (const gchar *first_element,
va_list *args)
{
g_return_val_if_fail (first_element != NULL, NULL);
return g_build_filename_va (first_element, args, NULL);
}
/**
* g_build_filenamev:
* @args: (array zero-terminated=1) (element-type filename): %NULL-terminated
* array of strings containing the path elements.
*
* Creates a filename from a vector of elements using the correct
* separator for the current platform.
*
* This function behaves exactly like g_build_filename(), but takes the path
* elements as a string array, instead of varargs. This function is mainly
* meant for language bindings.
*
* If you are building a path programmatically you may want to use
* #GPathBuf instead.
*
* Returns: (type filename) (transfer full): the newly allocated path
*
* Since: 2.8
*/
gchar *
g_build_filenamev (gchar **args)
{
return g_build_filename_va (NULL, NULL, args);
}
/**
* g_build_filename:
* @first_element: (type filename): the first element in the path
* @...: remaining elements in path, terminated by %NULL
*
* Creates a filename from a series of elements using the correct
* separator for the current platform.
*
* On Unix, this function behaves identically to `g_build_path
* (G_DIR_SEPARATOR_S, first_element, ....)`.
*
* On Windows, it takes into account that either the backslash
* (`\` or slash (`/`) can be used as separator in filenames, but
* otherwise behaves as on UNIX. When file pathname separators need
* to be inserted, the one that last previously occurred in the
* parameters (reading from left to right) is used.
*
* No attempt is made to force the resulting filename to be an absolute
* path. If the first element is a relative path, the result will
* be a relative path.
*
* If you are building a path programmatically you may want to use
* #GPathBuf instead.
*
* Returns: (type filename) (transfer full): the newly allocated path
*/
gchar *
g_build_filename (const gchar *first_element,
...)
{
gchar *str;
va_list args;
va_start (args, first_element);
str = g_build_filename_va (first_element, &args, NULL);
va_end (args);
return str;
}
/**
* g_file_read_link:
* @filename: (type filename): the symbolic link
* @error: return location for a #GError
*
* Reads the contents of the symbolic link @filename like the POSIX
* `readlink()` function.
*
* The returned string is in the encoding used for filenames. Use
* g_filename_to_utf8() to convert it to UTF-8.
*
* The returned string may also be a relative path. Use g_build_filename()
* to convert it to an absolute path:
*
* |[<!-- language="C" -->
* g_autoptr(GError) local_error = NULL;
* g_autofree gchar *link_target = g_file_read_link ("/etc/localtime", &local_error);
*
* if (local_error != NULL)
* g_error ("Error reading link: %s", local_error->message);
*
* if (!g_path_is_absolute (link_target))
* {
* g_autofree gchar *absolute_link_target = g_build_filename ("/etc", link_target, NULL);
* g_free (link_target);
* link_target = g_steal_pointer (&absolute_link_target);
* }
* ]|
*
* Returns: (type filename) (transfer full): A newly-allocated string with
* the contents of the symbolic link, or %NULL if an error occurred.
*
* Since: 2.4
*/
gchar *
g_file_read_link (const gchar *filename,
GError **error)
{
#if defined (HAVE_READLINK)
gchar *buffer;
size_t size;
gssize read_size;
g_return_val_if_fail (filename != NULL, NULL);
g_return_val_if_fail (error == NULL || *error == NULL, NULL);
size = 256;
buffer = g_malloc (size);
while (TRUE)
{
read_size = readlink (filename, buffer, size);
if (read_size < 0)
{
int saved_errno = errno;
if (error)
set_file_error (error,
filename,
_("Failed to read the symbolic link “%s”: %s"),
saved_errno);
g_free (buffer);
return NULL;
}
if ((size_t) read_size < size)
{
buffer[read_size] = 0;
return buffer;
}
size *= 2;
buffer = g_realloc (buffer, size);
}
#elif defined (G_OS_WIN32)
gchar *buffer;
gssize read_size;
g_return_val_if_fail (filename != NULL, NULL);
g_return_val_if_fail (error == NULL || *error == NULL, NULL);
read_size = g_win32_readlink_utf8 (filename, NULL, 0, &buffer, TRUE);
if (read_size < 0)
{
int saved_errno = errno;
if (error)
set_file_error (error,
filename,
_("Failed to read the symbolic link “%s”: %s"),
saved_errno);
return NULL;
}
else if (read_size == 0)
return strdup ("");
else
return buffer;
#else
g_return_val_if_fail (filename != NULL, NULL);
g_return_val_if_fail (error == NULL || *error == NULL, NULL);
g_set_error_literal (error,
G_FILE_ERROR,
G_FILE_ERROR_INVAL,
_("Symbolic links not supported"));
return NULL;
#endif
}
/**
* g_path_is_absolute:
* @file_name: (type filename): a file name
*
* Returns %TRUE if the given @file_name is an absolute file name.
* Note that this is a somewhat vague concept on Windows.
*
* On POSIX systems, an absolute file name is well-defined. It always
* starts from the single root directory. For example "/usr/local".
*
* On Windows, the concepts of current drive and drive-specific
* current directory introduce vagueness. This function interprets as
* an absolute file name one that either begins with a directory
* separator such as "\Users\tml" or begins with the root on a drive,
* for example "C:\Windows". The first case also includes UNC paths
* such as "\\\\myserver\docs\foo". In all cases, either slashes or
* backslashes are accepted.
*
* Note that a file name relative to the current drive root does not
* truly specify a file uniquely over time and across processes, as
* the current drive is a per-process value and can be changed.
*
* File names relative the current directory on some specific drive,
* such as "D:foo/bar", are not interpreted as absolute by this
* function, but they obviously are not relative to the normal current
* directory as returned by getcwd() or g_get_current_dir()
* either. Such paths should be avoided, or need to be handled using
* Windows-specific code.
*
* Returns: %TRUE if @file_name is absolute
*/
gboolean
g_path_is_absolute (const gchar *file_name)
{
g_return_val_if_fail (file_name != NULL, FALSE);
if (G_IS_DIR_SEPARATOR (file_name[0]))
return TRUE;
#ifdef G_OS_WIN32
/* Recognize drive letter on native Windows */
if (g_ascii_isalpha (file_name[0]) &&
file_name[1] == ':' && G_IS_DIR_SEPARATOR (file_name[2]))
return TRUE;
#endif
return FALSE;
}
/**
* g_path_skip_root:
* @file_name: (type filename): a file name
*
* Returns a pointer into @file_name after the root component,
* i.e. after the "/" in UNIX or "C:\" under Windows. If @file_name
* is not an absolute path it returns %NULL.
*
* Returns: (type filename) (nullable): a pointer into @file_name after the
* root component
*/
const gchar *
g_path_skip_root (const gchar *file_name)
{
g_return_val_if_fail (file_name != NULL, NULL);
#ifdef G_PLATFORM_WIN32
/* Skip \\server\share or //server/share */
if (G_IS_DIR_SEPARATOR (file_name[0]) &&
G_IS_DIR_SEPARATOR (file_name[1]) &&
file_name[2] &&
!G_IS_DIR_SEPARATOR (file_name[2]))
{
gchar *p;
p = strchr (file_name + 2, G_DIR_SEPARATOR);
#ifdef G_OS_WIN32
{
gchar *q;
q = strchr (file_name + 2, '/');
if (p == NULL || (q != NULL && q < p))
p = q;
}
#endif
if (p && p > file_name + 2 && p[1])
{
file_name = p + 1;
while (file_name[0] && !G_IS_DIR_SEPARATOR (file_name[0]))
file_name++;
/* Possibly skip a backslash after the share name */
if (G_IS_DIR_SEPARATOR (file_name[0]))
file_name++;
return (gchar *)file_name;
}
}
#endif
/* Skip initial slashes */
if (G_IS_DIR_SEPARATOR (file_name[0]))
{
while (G_IS_DIR_SEPARATOR (file_name[0]))
file_name++;
return (gchar *)file_name;
}
#ifdef G_OS_WIN32
/* Skip X:\ */
if (g_ascii_isalpha (file_name[0]) &&
file_name[1] == ':' &&
G_IS_DIR_SEPARATOR (file_name[2]))
return (gchar *)file_name + 3;
#endif
return NULL;
}
/**
* g_basename:
* @file_name: (type filename): the name of the file
*
* Gets the name of the file without any leading directory
* components. It returns a pointer into the given file name
* string.
*
* Returns: (type filename): the name of the file without any leading
* directory components
*
* Deprecated:2.2: Use g_path_get_basename() instead, but notice
* that g_path_get_basename() allocates new memory for the
* returned string, unlike this function which returns a pointer
* into the argument.
*/
const gchar *
g_basename (const gchar *file_name)
{
gchar *base;
g_return_val_if_fail (file_name != NULL, NULL);
base = strrchr (file_name, G_DIR_SEPARATOR);
#ifdef G_OS_WIN32
{
gchar *q;
q = strrchr (file_name, '/');
if (base == NULL || (q != NULL && q > base))
base = q;
}
#endif
if (base)
return base + 1;
#ifdef G_OS_WIN32
if (g_ascii_isalpha (file_name[0]) && file_name[1] == ':')
return (gchar*) file_name + 2;
#endif
return (gchar*) file_name;
}
/**
* g_path_get_basename:
* @file_name: (type filename): the name of the file
*
* Gets the last component of the filename.
*
* If @file_name ends with a directory separator it gets the component
* before the last slash. If @file_name consists only of directory
* separators (and on Windows, possibly a drive letter), a single
* separator is returned. If @file_name is empty, it gets ".".
*
* Returns: (type filename) (transfer full): a newly allocated string
* containing the last component of the filename
*/
gchar *
g_path_get_basename (const gchar *file_name)
{
gssize base;
gssize last_nonslash;
gsize len;
gchar *retval;
g_return_val_if_fail (file_name != NULL, NULL);
if (file_name[0] == '\0')
return g_strdup (".");
last_nonslash = strlen (file_name) - 1;
while (last_nonslash >= 0 && G_IS_DIR_SEPARATOR (file_name [last_nonslash]))
last_nonslash--;
if (last_nonslash == -1)
/* string only containing slashes */
return g_strdup (G_DIR_SEPARATOR_S);
#ifdef G_OS_WIN32
if (last_nonslash == 1 &&
g_ascii_isalpha (file_name[0]) &&
file_name[1] == ':')
/* string only containing slashes and a drive */
return g_strdup (G_DIR_SEPARATOR_S);
#endif
base = last_nonslash;
while (base >=0 && !G_IS_DIR_SEPARATOR (file_name [base]))
base--;
#ifdef G_OS_WIN32
if (base == -1 &&
g_ascii_isalpha (file_name[0]) &&
file_name[1] == ':')
base = 1;
#endif /* G_OS_WIN32 */
len = last_nonslash - base;
retval = g_malloc (len + 1);
memcpy (retval, file_name + (base + 1), len);
retval [len] = '\0';
return retval;
}
/**
* g_dirname:
* @file_name: (type filename): the name of the file
*
* Gets the directory components of a file name.
*
* If the file name has no directory components "." is returned.
* The returned string should be freed when no longer needed.
*
* Returns: (type filename) (transfer full): the directory components of the file
*
* Deprecated: use g_path_get_dirname() instead
*/
/**
* g_path_get_dirname:
* @file_name: (type filename): the name of the file
*
* Gets the directory components of a file name. For example, the directory
* component of `/usr/bin/test` is `/usr/bin`. The directory component of `/`
* is `/`.
*
* If the file name has no directory components "." is returned.
* The returned string should be freed when no longer needed.
*
* Returns: (type filename) (transfer full): the directory components of the file
*/
gchar *
g_path_get_dirname (const gchar *file_name)
{
gchar *base;
gsize len;
g_return_val_if_fail (file_name != NULL, NULL);
base = strrchr (file_name, G_DIR_SEPARATOR);
#ifdef G_OS_WIN32
{
gchar *q;
q = strrchr (file_name, '/');
if (base == NULL || (q != NULL && q > base))
base = q;
}
#endif
if (!base)
{
#ifdef G_OS_WIN32
if (g_ascii_isalpha (file_name[0]) && file_name[1] == ':')
{
gchar drive_colon_dot[4];
drive_colon_dot[0] = file_name[0];
drive_colon_dot[1] = ':';
drive_colon_dot[2] = '.';
drive_colon_dot[3] = '\0';
return g_strdup (drive_colon_dot);
}
#endif
return g_strdup (".");
}
while (base > file_name && G_IS_DIR_SEPARATOR (*base))
base--;
#ifdef G_OS_WIN32
/* base points to the char before the last slash.
*
* In case file_name is the root of a drive (X:\) or a child of the
* root of a drive (X:\foo), include the slash.
*
* In case file_name is the root share of an UNC path
* (\\server\share), add a slash, returning \\server\share\ .
*
* In case file_name is a direct child of a share in an UNC path
* (\\server\share\foo), include the slash after the share name,
* returning \\server\share\ .
*/
if (base == file_name + 1 &&
g_ascii_isalpha (file_name[0]) &&
file_name[1] == ':')
base++;
else if (G_IS_DIR_SEPARATOR (file_name[0]) &&
G_IS_DIR_SEPARATOR (file_name[1]) &&
file_name[2] &&
!G_IS_DIR_SEPARATOR (file_name[2]) &&
base >= file_name + 2)
{
const gchar *p = file_name + 2;
while (*p && !G_IS_DIR_SEPARATOR (*p))
p++;
if (p == base + 1)
{
len = (guint) strlen (file_name) + 1;
base = g_new (gchar, len + 1);
strcpy (base, file_name);
base[len-1] = G_DIR_SEPARATOR;
base[len] = 0;
return base;
}
if (G_IS_DIR_SEPARATOR (*p))
{
p++;
while (*p && !G_IS_DIR_SEPARATOR (*p))
p++;
if (p == base + 1)
base++;
}
}
#endif
len = (guint) 1 + base - file_name;
base = g_new (gchar, len + 1);
memmove (base, file_name, len);
base[len] = 0;
return base;
}
/**
* g_canonicalize_filename:
* @filename: (type filename): the name of the file
* @relative_to: (type filename) (nullable): the relative directory, or %NULL
* to use the current working directory
*
* Gets the canonical file name from @filename. All triple slashes are turned into
* single slashes, and all `..` and `.`s resolved against @relative_to.
*
* Symlinks are not followed, and the returned path is guaranteed to be absolute.
*
* If @filename is an absolute path, @relative_to is ignored. Otherwise,
* @relative_to will be prepended to @filename to make it absolute. @relative_to
* must be an absolute path, or %NULL. If @relative_to is %NULL, it'll fallback
* to g_get_current_dir().
*
* This function never fails, and will canonicalize file paths even if they don't
* exist.
*
* No file system I/O is done.
*
* Returns: (type filename) (transfer full): a newly allocated string with the
* canonical file path
*
* Since: 2.58
*/
gchar *
g_canonicalize_filename (const gchar *filename,
const gchar *relative_to)
{
gchar *canon, *input, *output, *after_root, *output_start;
g_return_val_if_fail (relative_to == NULL || g_path_is_absolute (relative_to), NULL);
if (!g_path_is_absolute (filename))
{
gchar *cwd_allocated = NULL;
const gchar *cwd;
if (relative_to != NULL)
cwd = relative_to;
else
cwd = cwd_allocated = g_get_current_dir ();
canon = g_build_filename (cwd, filename, NULL);
g_free (cwd_allocated);
}
else
{
canon = g_strdup (filename);
}
after_root = (char *)g_path_skip_root (canon);
if (after_root == NULL)
{
/* This shouldn't really happen, as g_get_current_dir() should
return an absolute pathname, but bug 573843 shows this is
not always happening */
g_free (canon);
return g_build_filename (G_DIR_SEPARATOR_S, filename, NULL);
}
/* Find the first dir separator and use the canonical dir separator. */
for (output = after_root - 1;
(output >= canon) && G_IS_DIR_SEPARATOR (*output);
output--)
*output = G_DIR_SEPARATOR;
/* 1 to re-increment after the final decrement above (so that output >= canon),
* and 1 to skip the first `/`. There might not be a first `/` if
* the @canon is a Windows `//server/share` style path with no
* trailing directories. @after_root will be '\0' in that case. */
output++;
if (*output == G_DIR_SEPARATOR)
output++;
/* POSIX allows double slashes at the start to mean something special
* (as does windows too). So, "//" != "/", but more than two slashes
* is treated as "/".
*/
if (after_root - output == 1)
output++;
input = after_root;
output_start = output;
while (*input)
{
/* input points to the next non-separator to be processed. */
/* output points to the next location to write to. */
g_assert (input > canon && G_IS_DIR_SEPARATOR (input[-1]));
g_assert (output > canon && G_IS_DIR_SEPARATOR (output[-1]));
g_assert (input >= output);
/* Ignore repeated dir separators. */
while (G_IS_DIR_SEPARATOR (input[0]))
input++;
/* Ignore single dot directory components. */
if (input[0] == '.' && (input[1] == 0 || G_IS_DIR_SEPARATOR (input[1])))
{
if (input[1] == 0)
break;
input += 2;
}
/* Remove double-dot directory components along with the preceding
* path component. */
else if (input[0] == '.' && input[1] == '.' &&
(input[2] == 0 || G_IS_DIR_SEPARATOR (input[2])))
{
if (output > output_start)
{
do
{
output--;
}
while (!G_IS_DIR_SEPARATOR (output[-1]) && output > output_start);
}
if (input[2] == 0)
break;
input += 3;
}
/* Copy the input to the output until the next separator,
* while converting it to canonical separator */
else
{
while (*input && !G_IS_DIR_SEPARATOR (*input))
*output++ = *input++;
if (input[0] == 0)
break;
input++;
*output++ = G_DIR_SEPARATOR;
}
}
/* Remove a potentially trailing dir separator */
if (output > output_start && G_IS_DIR_SEPARATOR (output[-1]))
output--;
*output = '\0';
return canon;
}
#if defined(MAXPATHLEN)
#define G_PATH_LENGTH MAXPATHLEN
#elif defined(PATH_MAX)
#define G_PATH_LENGTH PATH_MAX
#elif defined(_PC_PATH_MAX)
#define G_PATH_LENGTH sysconf(_PC_PATH_MAX)
#else
#define G_PATH_LENGTH 2048
#endif
/**
* g_get_current_dir:
*
* Gets the current directory.
*
* The returned string should be freed when no longer needed.
* The encoding of the returned string is system defined.
* On Windows, it is always UTF-8.
*
* Since GLib 2.40, this function will return the value of the "PWD"
* environment variable if it is set and it happens to be the same as
* the current directory. This can make a difference in the case that
* the current directory is the target of a symbolic link.
*
* Returns: (type filename) (transfer full): the current directory
*/
gchar *
g_get_current_dir (void)
{
#ifdef G_OS_WIN32
gchar *dir = NULL;
wchar_t dummy[2], *wdir;
DWORD len;
len = GetCurrentDirectoryW (2, dummy);
wdir = g_new (wchar_t, len);
if (GetCurrentDirectoryW (len, wdir) == len - 1)
dir = g_utf16_to_utf8 (wdir, -1, NULL, NULL, NULL);
g_free (wdir);
if (dir == NULL)
dir = g_strdup ("\\");
return dir;
#else
const gchar *pwd;
gchar *buffer = NULL;
gchar *dir = NULL;
static gsize buffer_size = 0;
struct stat pwdbuf, dotbuf;
pwd = g_getenv ("PWD");
if (pwd != NULL &&
g_stat (".", &dotbuf) == 0 && g_stat (pwd, &pwdbuf) == 0 &&
dotbuf.st_dev == pwdbuf.st_dev && dotbuf.st_ino == pwdbuf.st_ino)
return g_strdup (pwd);
if (buffer_size == 0)
buffer_size = (G_PATH_LENGTH == -1) ? 2048 : G_PATH_LENGTH;
while (buffer_size < G_MAXSIZE / 2)
{
g_free (buffer);
buffer = g_new (gchar, buffer_size);
*buffer = 0;
dir = getcwd (buffer, buffer_size);
if (dir || errno != ERANGE)
break;
buffer_size *= 2;
}
/* Check that getcwd() nul-terminated the string. It should do, but the specs
* don’t actually explicitly state that:
* https://pubs.opengroup.org/onlinepubs/9699919799/functions/getcwd.html */
g_assert (dir == NULL || strnlen (dir, buffer_size) < buffer_size);
if (!dir || !*buffer)
{
/* Fallback return value */
g_assert (buffer_size >= 2);
buffer[0] = G_DIR_SEPARATOR;
buffer[1] = 0;
}
dir = g_strdup (buffer);
g_free (buffer);
return dir;
#endif /* !G_OS_WIN32 */
}
#ifdef G_OS_WIN32
/* Binary compatibility versions. Not for newly compiled code. */
_GLIB_EXTERN gboolean g_file_test_utf8 (const gchar *filename,
GFileTest test);
_GLIB_EXTERN gboolean g_file_get_contents_utf8 (const gchar *filename,
gchar **contents,
gsize *length,
GError **error);
_GLIB_EXTERN gint g_mkstemp_utf8 (gchar *tmpl);
_GLIB_EXTERN gint g_file_open_tmp_utf8 (const gchar *tmpl,
gchar **name_used,
GError **error);
_GLIB_EXTERN gchar *g_get_current_dir_utf8 (void);
gboolean
g_file_test_utf8 (const gchar *filename,
GFileTest test)
{
return g_file_test (filename, test);
}
gboolean
g_file_get_contents_utf8 (const gchar *filename,
gchar **contents,
gsize *length,
GError **error)
{
return g_file_get_contents (filename, contents, length, error);
}
gint
g_mkstemp_utf8 (gchar *tmpl)
{
return g_mkstemp (tmpl);
}
gint
g_file_open_tmp_utf8 (const gchar *tmpl,
gchar **name_used,
GError **error)
{
return g_file_open_tmp (tmpl, name_used, error);
}
gchar *
g_get_current_dir_utf8 (void)
{
return g_get_current_dir ();
}
#endif
Reference in New Issue View Git Blame Copy Permalink