glib.FileUtils.FileUtils Class Reference

List of all members.

Detailed Description

Description 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. 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().


Static Public Member Functions

static GFileError fileErrorFromErrno (int errNo)
 Gets a GFileError constant based on the passed-in errno.
static int fileGetContents (char[] filename, char **contents, uint *length, GError **error)
 Reads an entire file into allocated memory, with good error checking.
static int fileSetContents (char[] filename, char[] contents, int length, GError **error)
 Writes all of contents to a file named filename, with good error checking.
static int fileTest (char[] filename, GFileTest test)
 Returns TRUE if any of the tests in the bitfield test are TRUE.
static int mkstemp (char[] tmpl)
 Opens a temporary file.
static int fileOpenTmp (char[] tmpl, char **nameUsed, GError **error)
 Opens a file for writing in the preferred directory for temporary files (as returned by g_get_tmp_dir()).
static char[] fileReadLink (char[] filename, GError **error)
 Reads the contents of the symbolic link filename like the POSIX readlink() function.
static int mkdirWithParents (char[] pathname, int mode)
 Create a directory if it doesn't already exist.
static GDirdirOpen (char[] path, uint flags, GError **error)
 Opens a directory for reading.
static char[] dirReadName (GDir *dir)
 Retrieves the name of the next entry in the directory.
static void dirRewind (GDir *dir)
 Resets the given directory.
static void dirClose (GDir *dir)
 Closes the directory and deallocates all related resources.
static GMappedFilemappedFileNew (char[] filename, int writable, GError **error)
 Maps a file into memory.
static void mappedFileFree (GMappedFile *file)
 Unmaps the buffer of file and frees it.
static uint mappedFileGetLength (GMappedFile *file)
 Returns the length of the contents of a GMappedFile.
static char[] mappedFileGetContents (GMappedFile *file)
 Returns the contents of a GMappedFile.
static int open (char[] filename, int flags, int mode)
 A wrapper for the POSIX open() function.
static int rename (char[] oldfilename, char[] newfilename)
 A wrapper for the POSIX rename() function.
static int mkdir (char[] filename, int mode)
 A wrapper for the POSIX mkdir() function.
static int stat (char[] filename, void *buf)
 A wrapper for the POSIX stat() function.
static int lstat (char[] filename, void *buf)
 A wrapper for the POSIX lstat() function.
static int unlink (char[] filename)
 A wrapper for the POSIX unlink() function.
static int remove (char[] filename)
 A wrapper for the POSIX remove() function.
static int rmdir (char[] filename)
 A wrapper for the POSIX rmdir() function.
static FILE * fopen (char[] filename, char[] mode)
 A wrapper for the POSIX fopen() function.
static FILE * freopen (char[] filename, char[] mode, FILE *stream)
 A wrapper for the POSIX freopen() function.
static int chmod (char[] filename, int mode)
 A wrapper for the POSIX chmod() function.
static int access (char[] filename, int mode)
 A wrapper for the POSIX access() function.
static int creat (char[] filename, int mode)
 A wrapper for the POSIX creat() function.
static int chdir (char[] path)
 A wrapper for the POSIX chdir() function.


Member Function Documentation

static int glib.FileUtils.FileUtils.access ( char[]  filename,
int  mode 
) [static]

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 underlying access() function in the C library only checks the READONLY attribute, and does not look at the ACL at all. Software that needs to handle file permissions on Windows more exactly should use the Win32 API. See the C library manual for more details about access(). filename: a pathname in the GLib file name encoding (UTF-8 on Windows) mode: as in 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

static int glib.FileUtils.FileUtils.chdir ( char[]  path  )  [static]

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(). path: a pathname in the GLib file name encoding (UTF-8 on Windows) Returns: 0 on success, -1 if an error occurred. Since 2.8

static int glib.FileUtils.FileUtils.chmod ( char[]  filename,
int  mode 
) [static]

A wrapper for the POSIX chmod() function.

The chmod() function is used to set the permissions of a file system object. Note that 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 READONLY attribute. It does not touch any ACL. Software that needs to manage file permissions on Windows exactly should use the Win32 API. See the C library manual for more details about chmod(). filename: a pathname in the GLib file name encoding (UTF-8 on Windows) mode: as in chmod() Returns: zero if the operation succeeded, -1 on error. Since 2.8

static int glib.FileUtils.FileUtils.creat ( char[]  filename,
int  mode 
) [static]

A wrapper for the POSIX creat() function.

The creat() function is used to convert a pathname into a file descriptor, creating a file if necessar. Note that 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 something different. See the C library manual for more details about creat(). filename: a pathname in the GLib file name encoding (UTF-8 on Windows) mode: as in 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

static void glib.FileUtils.FileUtils.dirClose ( GDir dir  )  [static]

Closes the directory and deallocates all related resources.

dir: a GDir* created by g_dir_open()

static GDir* glib.FileUtils.FileUtils.dirOpen ( char[]  path,
uint  flags,
GError **  error 
) [static]

Opens a directory for reading.

The names of the files in the directory can then be retrieved using g_dir_read_name(). path: the path to the directory you are interested in. On Unix in the on-disk encoding. On Windows in UTF-8 flags: Currently must be set to 0. Reserved for future use. error: return location for a GError, or NULL. If non-NULL, an error will be set if and only if g_dir_open() fails. Returns: a newly allocated GDir on success, NULL on failure. If non-NULL, you must free the result with g_dir_close() when you are finished with it.

static char [] glib.FileUtils.FileUtils.dirReadName ( GDir dir  )  [static]

Retrieves the name of the next entry in the directory.

The '.' and '..' entries are omitted. On Windows, the returned name is in UTF-8. On Unix, it is in the on-disk encoding. dir: a GDir* created by g_dir_open() Returns: The entry's name or NULL if there are no more entries. The return value is owned by GLib and must not be modified or freed.

static void glib.FileUtils.FileUtils.dirRewind ( GDir dir  )  [static]

Resets the given directory.

The next call to g_dir_read_name() will return the first entry again. dir: a GDir* created by g_dir_open()

static GFileError glib.FileUtils.FileUtils.fileErrorFromErrno ( int  errNo  )  [static]

Gets a GFileError constant based on the passed-in errno.

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. err_no: an "errno" value Returns: GFileError corresponding to the given errno

static int glib.FileUtils.FileUtils.fileGetContents ( char[]  filename,
char **  contents,
uint length,
GError **  error 
) [static]

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. filename: name of a file to read contents from, in the GLib file name encoding contents: location to store an allocated string length: location to store length in bytes of the contents, or NULL error: return location for a GError, or NULL Returns: TRUE on success, FALSE if an error occurred

static int glib.FileUtils.FileUtils.fileOpenTmp ( char[]  tmpl,
char **  nameUsed,
GError **  error 
) [static]

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. The actual name used is returned in name_used if non-NULL. This string should be freed with g_free() when not needed any longer. The returned name is in the GLib file name encoding. tmpl: Template for file name, as in g_mkstemp(), basename only, or NULL, to a default template name_used: location to store actual name used error: return location for a GError 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.

static char [] glib.FileUtils.FileUtils.fileReadLink ( char[]  filename,
GError **  error 
) [static]

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. filename: the symbolic link error: return location for a GError Returns: A newly allocated string with the contents of the symbolic link, or NULL if an error occurred. Since 2.4

static int glib.FileUtils.FileUtils.fileSetContents ( char[]  filename,
char[]  contents,
int  length,
GError **  error 
) [static]

Writes all of contents to a file named filename, with good error checking.

If a file called filename already exists it will be overwritten. This write 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 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 sucessful, 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. filename: name of a file to write contents to, in the GLib file name encoding contents: 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 Returns: TRUE on success, FALSE if an error occurred Since 2.8

static int glib.FileUtils.FileUtils.fileTest ( char[]  filename,
GFileTest  test 
) [static]

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. For example, you might think you could use G_FILE_TEST_IS_SYMLINK to know whether it is is safe to write to a file without being tricked into writing into a different location. It doesn't work! /+* DON'T DO THIS +/ if (!g_file_test (filename, G_FILE_TEST_IS_SYMLINK)) { fd = g_open (filename, O_WRONLY); /+* 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. filename: a filename to test in the GLib file name encoding test: bitfield of GFileTest flags Returns: whether a test was TRUE

static FILE* glib.FileUtils.FileUtils.fopen ( char[]  filename,
char[]  mode 
) [static]

A wrapper for the POSIX fopen() function.

The fopen() function opens a file and associates a new stream with it. See the C library manual for more details about fopen(). 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 Returns: A FILE pointer if the file was successfully opened, or NULL if an error occurred Since 2.6

static FILE* glib.FileUtils.FileUtils.freopen ( char[]  filename,
char[]  mode,
FILE *  stream 
) [static]

A wrapper for the POSIX freopen() function.

The freopen() function opens a file and associates it with an existing stream. See the C library manual for more details about freopen(). 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: an existing stream which will be reused, or NULL Returns: A FILE pointer if the file was successfully opened, or NULL if an error occurred. Since 2.6

static int glib.FileUtils.FileUtils.lstat ( char[]  filename,
void *  buf 
) [static]

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 the C library manual for more details about lstat(). 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 Returns: 0 if the information was successfully retrieved, -1 if an error occurred Since 2.6

static void glib.FileUtils.FileUtils.mappedFileFree ( GMappedFile file  )  [static]

Unmaps the buffer of file and frees it.

file: a GMappedFile Since 2.8

static char [] glib.FileUtils.FileUtils.mappedFileGetContents ( GMappedFile file  )  [static]

Returns the contents of a GMappedFile.

Note that the contents may not be zero-terminated, even if the GMappedFile is backed by a text file. file: a GMappedFile Returns: the contents of file. Since 2.8

static uint glib.FileUtils.FileUtils.mappedFileGetLength ( GMappedFile file  )  [static]

Returns the length of the contents of a GMappedFile.

file: a GMappedFile Returns: the length of the contents of file. Since 2.8

static GMappedFile* glib.FileUtils.FileUtils.mappedFileNew ( char[]  filename,
int  writable,
GError **  error 
) [static]

Maps a file into memory.

On UNIX, this is using the mmap() function. If writable is TRUE, the mapped buffer may be modified, otherwise it is an error to modify the mapped buffer. Modifications to the buffer are not visible to other processes mapping the same file, and are not written back to the file. Note that modifications of the underlying file might affect the contents of the GMappedFile. Therefore, mapping should only be used if the file will not be modified, or if all modifications of the file are done atomically (e.g. using g_file_set_contents()). filename: The path of the file to load, in the GLib filename encoding writable: wether the mapping should be writable error: return location for a GError, or NULL Returns: a newly allocated GMappedFile which must be freed with g_mapped_file_free(), or NULL if the mapping failed. Since 2.8

static int glib.FileUtils.FileUtils.mkdir ( char[]  filename,
int  mode 
) [static]

A wrapper for the POSIX mkdir() function.

The mkdir() function attempts to create a directory with the given name and permissions. See the C library manual for more details about mkdir(). filename: a pathname in the GLib file name encoding (UTF-8 on Windows) mode: permissions to use for the newly created directory Returns: 0 if the directory was successfully created, -1 if an error occurred Since 2.6

static int glib.FileUtils.FileUtils.mkdirWithParents ( char[]  pathname,
int  mode 
) [static]

Create a directory if it doesn't already exist.

Create intermediate parent directories as needed, too. pathname: a pathname in the GLib file name encoding mode: permissions to use for newly created directories Returns: 0 if the directory already exists, or was successfully created. Returns -1 if an error occurred, with errno set. Since 2.8

static int glib.FileUtils.FileUtils.mkstemp ( char[]  tmpl  )  [static]

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. tmpl: template filename 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.

static int glib.FileUtils.FileUtils.open ( char[]  filename,
int  flags,
int  mode 
) [static]

A wrapper for the POSIX open() function.

The open() function is used to convert a pathname into a file descriptor. Note that 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 Windows API for opening files is something different. See the C library manual for more details about open(). filename: a pathname in the GLib file name encoding (UTF-8 on Windows) flags: as in open() mode: as in 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

static int glib.FileUtils.FileUtils.remove ( char[]  filename  )  [static]

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(). filename: a pathname in the GLib file name encoding (UTF-8 on Windows) Returns: 0 if the file was successfully removed, -1 if an error occurred Since 2.6

static int glib.FileUtils.FileUtils.rename ( char[]  oldfilename,
char[]  newfilename 
) [static]

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. Note in particular that on Win9x it is not possible to rename a file if a file with the new name already exists. Also it is not possible in general on Windows to rename an open file. oldfilename: a pathname in the GLib file name encoding (UTF-8 on Windows) newfilename: a pathname in the GLib file name encoding Returns: 0 if the renaming succeeded, -1 if an error occurred Since 2.6

static int glib.FileUtils.FileUtils.rmdir ( char[]  filename  )  [static]

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. filename: a pathname in the GLib file name encoding (UTF-8 on Windows) Returns: 0 if the directory was successfully removed, -1 if an error occurred Since 2.6

static int glib.FileUtils.FileUtils.stat ( char[]  filename,
void *  buf 
) [static]

A wrapper for the POSIX stat() function.

The stat() function returns information about a file. See the C library manual for more details about stat(). 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 Returns: 0 if the information was successfully retrieved, -1 if an error occurred Since 2.6

static int glib.FileUtils.FileUtils.unlink ( char[]  filename  )  [static]

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. filename: a pathname in the GLib file name encoding (UTF-8 on Windows) Returns: 0 if the name was successfully deleted, -1 if an error occurred Since 2.6


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