GFileOutputStream: GIO Reference Manual

GFileOutputStream

GFileOutputStream — File output streaming operations

Functions

GFileInfo *	g_file_output_stream_query_info ()
void	g_file_output_stream_query_info_async ()
GFileInfo *	g_file_output_stream_query_info_finish ()
char *	g_file_output_stream_get_etag ()

Types and Values

GFileOutputStream

Object Hierarchy

    GObject
    ╰── GOutputStream
        ╰── GFileOutputStream

Implemented Interfaces

GFileOutputStream implements GSeekable.

Includes

#include <gio/gio.h>

Description

GFileOutputStream provides output streams that write their content to a file.

GFileOutputStream implements GSeekable, which allows the output stream to jump to arbitrary positions in the file and to truncate the file, provided the filesystem of the file supports these operations.

To find the position of a file output stream, use g_seekable_tell(). To find out if a file output stream supports seeking, use g_seekable_can_seek().To position a file output stream, use g_seekable_seek(). To find out if a file output stream supports truncating, use g_seekable_can_truncate(). To truncate a file output stream, use g_seekable_truncate().

Functions

g_file_output_stream_query_info ()

GFileInfo *
g_file_output_stream_query_info (GFileOutputStream *stream,
                                 const char *attributes,
                                 GCancellable *cancellable,
                                 GError **error);

Queries a file output stream for the given attributes . This function blocks while querying the stream. For the asynchronous version of this function, see g_file_output_stream_query_info_async(). While the stream is blocked, the stream will set the pending flag internally, and any other operations on the stream will fail with G_IO_ERROR_PENDING.

Can fail if the stream was already closed (with error being set to G_IO_ERROR_CLOSED), the stream has pending operations (with error being set to G_IO_ERROR_PENDING), or if querying info is not supported for the stream's interface (with error being set to G_IO_ERROR_NOT_SUPPORTED). In all cases of failure, NULL will be returned.

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 set, and NULL will be returned.

Parameters

stream	a GFileOutputStream.
attributes	a file attribute query string.
cancellable	optional GCancellable object, `NULL` to ignore.
error	a GError, `NULL` to ignore.

Returns

a GFileInfo for the stream , or NULL on error.

[transfer full]

g_file_output_stream_query_info_async ()

void
g_file_output_stream_query_info_async (GFileOutputStream *stream,
                                       const char *attributes,
                                       int io_priority,
                                       GCancellable *cancellable,
                                       GAsyncReadyCallback callback,
                                       gpointer user_data);

Asynchronously queries the stream for a GFileInfo. When completed, callback will be called with a GAsyncResult which can be used to finish the operation with g_file_output_stream_query_info_finish().

For the synchronous version of this function, see g_file_output_stream_query_info().

Parameters

stream	a GFileOutputStream.
attributes	a file attribute query string.
io_priority	the I/O priority of the request
cancellable	optional GCancellable object, `NULL` to ignore.
callback	callback to call when the request is satisfied
user_data	the data to pass to callback function

g_file_output_stream_query_info_finish ()

GFileInfo *
g_file_output_stream_query_info_finish
                               (GFileOutputStream *stream,
                                GAsyncResult *result,
                                GError **error);

Finalizes the asynchronous query started by g_file_output_stream_query_info_async().

Parameters

stream	a GFileOutputStream.
result	a GAsyncResult.
error	a GError, `NULL` to ignore.

Returns

A GFileInfo for the finished query.

[transfer full]

g_file_output_stream_get_etag ()

char *
g_file_output_stream_get_etag (GFileOutputStream *stream);

Gets the entity tag for the file when it has been written. This must be called after the stream has been written and closed, as the etag can change while writing.

Parameters

stream

a GFileOutputStream.

Returns

the entity tag for the stream.

Types and Values