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GFileEnumerator allows you to operate on a set of GFiles,
returning a GFileInfo structure for each file enumerated (e.g.
g_file_enumerate_children()
will return a GFileEnumerator for each
of the children within a directory).
To get the next file's information from a GFileEnumerator, use
g_file_enumerator_next_file()
or its asynchronous version,
g_file_enumerator_next_files_async()
. Note that the asynchronous
version will return a list of GFileInfos, whereas the
synchronous will only return the next file in the enumerator.
The ordering of returned files is unspecified for non-Unix
platforms; for more information, see g_dir_read_name()
. On Unix,
when operating on local files, returned files will be sorted by
inode number. Effectively you can assume that the ordering of
returned files will be stable between successive calls (and
applications) assuming the directory is unchanged.
If your application needs a specific ordering, such as by name or modification time, you will have to implement that in your application code.
To close a GFileEnumerator, use g_file_enumerator_close()
, or
its asynchronous version, g_file_enumerator_close_async()
. Once
a GFileEnumerator is closed, no further actions may be performed
on it, and it should be freed with g_object_unref()
.
gboolean g_file_enumerator_iterate (GFileEnumerator *direnum
,GFileInfo **out_info
,GFile **out_child
,GCancellable *cancellable
,GError **error
);
This is a version of g_file_enumerator_next_file()
that's easier to
use correctly from C programs. With g_file_enumerator_next_file()
,
the gboolean return value signifies "end of iteration or error", which
requires allocation of a temporary GError.
In contrast, with this function, a FALSE
return from
g_file_enumerator_iterate()
*always* means
"error". End of iteration is signaled by out_info
or out_child
being NULL
.
Another crucial difference is that the references for out_info
and
out_child
are owned by direnum
(they are cached as hidden
properties). You must not unref them in your own code. This makes
memory management significantly easier for C code in combination
with loops.
Finally, this function optionally allows retrieving a GFile as well.
You must specify at least one of out_info
or out_child
.
The code pattern for correctly using g_file_enumerator_iterate()
from C
is:
1 2 3 4 5 6 7 8 9 10 11 12 13 |
direnum = g_file_enumerate_children (file, ...); while (TRUE) { GFileInfo *info; if (!g_file_enumerator_iterate (direnum, &info, NULL, cancellable, error)) goto out; if (!info) break; ... do stuff with "info"; do not unref it! ... } out: g_object_unref (direnum); // Note: frees the last @info |
direnum |
an open GFileEnumerator |
|
out_info |
[out][transfer none][optional] | |
out_child |
[out][transfer none][optional] | |
cancellable |
||
error |
a GError |
Since: 2.44
GFileInfo * g_file_enumerator_next_file (GFileEnumerator *enumerator
,GCancellable *cancellable
,GError **error
);
Returns information for the next file in the enumerated object. Will block until the information is available. The GFileInfo returned from this function will contain attributes that match the attribute string that was passed when the GFileEnumerator was created.
See the documentation of GFileEnumerator for information about the order of returned files.
On error, returns NULL
and sets error
to the error. If the
enumerator is at the end, NULL
will be returned and error
will
be unset.
enumerator |
||
cancellable |
optional GCancellable object, |
[nullable] |
error |
location to store the error occurring, or |
A GFileInfo or NULL
on error
or end of enumerator. Free the returned object with
g_object_unref()
when no longer needed.
[nullable][transfer full]
gboolean g_file_enumerator_close (GFileEnumerator *enumerator
,GCancellable *cancellable
,GError **error
);
Releases all resources used by this enumerator, making the
enumerator return G_IO_ERROR_CLOSED
on all calls.
This will be automatically called when the last reference is dropped, but you might want to call this function to make sure resources are released as early as possible.
enumerator |
||
cancellable |
optional GCancellable object, |
[nullable] |
error |
location to store the error occurring, or |
void g_file_enumerator_next_files_async (GFileEnumerator *enumerator
,int num_files
,int io_priority
,GCancellable *cancellable
,GAsyncReadyCallback callback
,gpointer user_data
);
Request information for a number of files from the enumerator asynchronously.
When all i/o for the operation is finished the callback
will be called with
the requested information.
See the documentation of GFileEnumerator for information about the order of returned files.
The callback can be called with less than num_files
files in case of error
or at the end of the enumerator. In case of a partial error the callback will
be called with any succeeding items and no error, and on the next request the
error will be reported. If a request is cancelled the callback will be called
with G_IO_ERROR_CANCELLED
.
During an async request no other sync and async calls are allowed, and will
result in G_IO_ERROR_PENDING
errors.
Any outstanding i/o request with higher priority (lower numerical value) will
be executed before an outstanding request with lower priority. Default
priority is G_PRIORITY_DEFAULT
.
enumerator |
||
num_files |
the number of file info objects to request |
|
io_priority |
the I/O priority of the request |
|
cancellable |
optional GCancellable object, |
[nullable] |
callback |
a GAsyncReadyCallback to call when the request is satisfied. |
[scope async] |
user_data |
the data to pass to callback function. |
[closure] |
GList * g_file_enumerator_next_files_finish (GFileEnumerator *enumerator
,GAsyncResult *result
,GError **error
);
Finishes the asynchronous operation started with g_file_enumerator_next_files_async()
.
enumerator |
||
result |
a GAsyncResult. |
|
error |
a GError location to store the error occurring, or |
a GList of GFileInfos. You must free the list with
g_list_free()
and unref the infos with g_object_unref()
when you're
done with them.
[transfer full][element-type Gio.FileInfo]
void g_file_enumerator_close_async (GFileEnumerator *enumerator
,int io_priority
,GCancellable *cancellable
,GAsyncReadyCallback callback
,gpointer user_data
);
Asynchronously closes the file enumerator.
If cancellable
is not NULL
, then the operation can be cancelled by
triggering the cancellable object from another thread. If the operation
was cancelled, the error G_IO_ERROR_CANCELLED
will be returned in
g_file_enumerator_close_finish()
.
enumerator |
||
io_priority |
the I/O priority of the request |
|
cancellable |
optional GCancellable object, |
[nullable] |
callback |
a GAsyncReadyCallback to call when the request is satisfied. |
[scope async] |
user_data |
the data to pass to callback function. |
[closure] |
gboolean g_file_enumerator_close_finish (GFileEnumerator *enumerator
,GAsyncResult *result
,GError **error
);
Finishes closing a file enumerator, started from g_file_enumerator_close_async()
.
If the file enumerator was already closed when g_file_enumerator_close_async()
was called, then this function will report G_IO_ERROR_CLOSED
in error
, and
return FALSE
. If the file enumerator had pending operation when the close
operation was started, then this function will report G_IO_ERROR_PENDING
, and
return FALSE
. If cancellable
was not NULL
, then the operation may have been
cancelled by triggering the cancellable object from another thread. If the operation
was cancelled, the error G_IO_ERROR_CANCELLED
will be set, and FALSE
will be
returned.
enumerator |
||
result |
a GAsyncResult. |
|
error |
a GError location to store the error occurring, or |
gboolean
g_file_enumerator_is_closed (GFileEnumerator *enumerator
);
Checks if the file enumerator has been closed.
gboolean
g_file_enumerator_has_pending (GFileEnumerator *enumerator
);
Checks if the file enumerator has pending operations.
void g_file_enumerator_set_pending (GFileEnumerator *enumerator
,gboolean pending
);
Sets the file enumerator as having pending operations.
GFile *
g_file_enumerator_get_container (GFileEnumerator *enumerator
);
Get the GFile container which is being enumerated.
Since: 2.18
GFile * g_file_enumerator_get_child (GFileEnumerator *enumerator
,GFileInfo *info
);
Return a new GFile which refers to the file named by info
in the source
directory of enumerator
. This function is primarily intended to be used
inside loops with g_file_enumerator_next_file()
.
This is a convenience method that's equivalent to:
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gchar *name = g_file_info_get_name (info); GFile *child = g_file_get_child (g_file_enumerator_get_container (enumr), name); |
enumerator |
||
info |
a GFileInfo gotten from |
Since: 2.36
“container”
property“container” GFile *
The container that is being enumerated.
Flags: Write / Construct Only