Gio::FileOutputStream Class Reference
Stream Classes

FileOutputStream provides output streams that write their content to a file. More...

`#include <giomm/fileoutputstream.h>`

Inheritance diagram for Gio::FileOutputStream:
[legend]

## Public Member Functions

| FileOutputStream (FileOutputStream&& src) noexcept
FileOutputStream& | operator= (FileOutputStream&& src) noexcept
| ~FileOutputStream () noexcept override
GFileOutputStream* | gobj ()
| Provides access to the underlying C GObject. More...
const GFileOutputStream* | gobj () const
| Provides access to the underlying C GObject. More...
GFileOutputStream* | gobj_copy ()
| Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs. More...
Glib::RefPtr< FileInfo > | query_info (const Glib::RefPtr< Cancellable >& cancellable, const std::string& attributes="*")
| Queries a file output stream for the given attributes . More...
Glib::RefPtr< FileInfo > | query_info (const std::string& attributes="*")
| Queries a file output stream for the given attributes . More...
void | query_info_async (const SlotAsyncReady& slot, const Glib::RefPtr< Cancellable >& cancellable, const std::string& attributes="*", int io_priority=Glib::PRIORITY_DEFAULT)
| Queries the stream information asynchronously. More...
void | query_info_async (const SlotAsyncReady& slot, const std::string& attributes="*", int io_priority=Glib::PRIORITY_DEFAULT)
| Queries the stream information asynchronously. More...
Glib::RefPtr< FileInfo > | query_info_finish (const Glib::RefPtr< AsyncResult >& result)
| Finalizes the asynchronous query started by g_file_output_stream_query_info_async(). More...
std::string | get_etag () const
| Gets the entity tag for the file when it has been written. More...
Public Member Functions inherited from Gio::OutputStream
| OutputStream (OutputStream&& src) noexcept
OutputStream& | operator= (OutputStream&& src) noexcept
| ~OutputStream () noexcept override
GOutputStream* | gobj ()
| Provides access to the underlying C GObject. More...
const GOutputStream* | gobj () const
| Provides access to the underlying C GObject. More...
GOutputStream* | gobj_copy ()
| Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs. More...
gssize | write (const void* buffer, gsize count, const Glib::RefPtr< Cancellable >& cancellable)
| Tries to write count bytes from buffer into the stream. More...
gssize | write (const void* buffer, gsize count)
| A write() convenience overload. More...
gssize | write (const std::string& buffer, const Glib::RefPtr< Cancellable >& cancellable)
| Tries to write count bytes from buffer into the stream. More...
gssize | write (const std::string& buffer)
| Tries to write count bytes from buffer into the stream. More...
bool | write_all (const void* buffer, gsize count, gsize& bytes_written, const Glib::RefPtr< Cancellable >& cancellable)
| Tries to write count bytes from buffer into the stream. More...
bool | write_all (const void* buffer, gsize count, gsize& bytes_written)
| A write_all() convenience overload. More...
bool | write_all (const std::string& buffer, gsize& bytes_written, const Glib::RefPtr< Cancellable >& cancellable)
| Tries to write count bytes from buffer into the stream. More...
bool | write_all (const std::string& buffer, gsize& bytes_written)
| Tries to write count bytes from buffer into the stream. More...
gssize | write_bytes (const Glib::RefPtr< const Glib::Bytes >& bytes, const Glib::RefPtr< Cancellable >& cancellable)
| A wrapper function for g_output_stream_write() which takes a Bytes as input. More...
gssize | write_bytes (const Glib::RefPtr< const Glib::Bytes >& bytes)
| A write_bytes() convenience overload. More...
void | write_bytes_async (const Glib::RefPtr< const Glib::Bytes >& bytes, const SlotAsyncReady& slot, const Glib::RefPtr< Cancellable >& cancellable, int io_priority=Glib::PRIORITY_DEFAULT)
| Request an asynchronous write of the data in bytes to the stream. More...
void | write_bytes_async (const Glib::RefPtr< const Glib::Bytes >& bytes, const SlotAsyncReady& slot, int io_priority=Glib::PRIORITY_DEFAULT)
| Request an asynchronous write of the data in bytes to the stream. More...
gssize | write_bytes_finish (const Glib::RefPtr< AsyncResult >& result)
| Finishes a stream write-from-Bytes operation. More...
gssize | splice (const Glib::RefPtr< InputStream >& source, const Glib::RefPtr< Cancellable >& cancellable, OutputStreamSpliceFlags flags=OUTPUT_STREAM_SPLICE_NONE)
| Splices an input stream into an output stream. More...
gssize | splice (const Glib::RefPtr< InputStream >& source, OutputStreamSpliceFlags flags=OUTPUT_STREAM_SPLICE_NONE)
| Splices an input stream into an output stream. More...
bool | flush (const Glib::RefPtr< Cancellable >& cancellable)
| Flushed any outstanding buffers in the stream. More...
bool | flush ()
| A flush() convenience overload. More...
bool | close (const Glib::RefPtr< Cancellable >& cancellable)
| Closes the stream, releasing resources related to it. More...
bool | close ()
| A close() convenience overload. More...
void | write_async (const void* buffer, gsize count, const SlotAsyncReady& slot, const Glib::RefPtr< Cancellable >& cancellable, int io_priority=Glib::PRIORITY_DEFAULT)
| Request an asynchronous write of count bytes from buffer into the stream. More...
void | write_async (const void* buffer, gsize count, const SlotAsyncReady& slot, int io_priority=Glib::PRIORITY_DEFAULT)
| Request an asynchronous write of count bytes from buffer into the stream. More...
gssize | write_finish (const Glib::RefPtr< AsyncResult >& result)
| Finishes a stream write operation. More...
void | write_all_async (const void* buffer, gsize count, const SlotAsyncReady& slot, const Glib::RefPtr< Cancellable >& cancellable, int io_priority=Glib::PRIORITY_DEFAULT)
| Request an asynchronous write of count bytes from buffer into the stream. More...
void | write_all_async (const void* buffer, gsize count, const SlotAsyncReady& slot, int io_priority=Glib::PRIORITY_DEFAULT)
| Request an asynchronous write of count bytes from buffer into the stream. More...
bool | write_all_finish (const Glib::RefPtr< AsyncResult >& result, gsize& bytes_written)
| Finishes an asynchronous stream write operation started with g_output_stream_write_all_async(). More...
void | splice_async (const Glib::RefPtr< InputStream >& source, const SlotAsyncReady& slot, const Glib::RefPtr< Cancellable >& cancellable, OutputStreamSpliceFlags flags=OUTPUT_STREAM_SPLICE_NONE, int io_priority=Glib::PRIORITY_DEFAULT)
| Splices a stream asynchronously. More...
void | splice_async (const Glib::RefPtr< InputStream >& source, const SlotAsyncReady& slot, OutputStreamSpliceFlags flags=OUTPUT_STREAM_SPLICE_NONE, int io_priority=Glib::PRIORITY_DEFAULT)
| Splices a stream asynchronously. More...
gssize | splice_finish (const Glib::RefPtr< AsyncResult >& result)
| Finishes an asynchronous stream splice operation. More...
void | flush_async (const SlotAsyncReady& slot, const Glib::RefPtr< Cancellable >& cancellable, int io_priority=Glib::PRIORITY_DEFAULT)
| Flushes a stream asynchronously. More...
void | flush_async (const SlotAsyncReady& slot, int io_priority=Glib::PRIORITY_DEFAULT)
| Flushes a stream asynchronously. More...
bool | flush_finish (const Glib::RefPtr< AsyncResult >& result)
| Finishes flushing an output stream. More...
void | close_async (const SlotAsyncReady& slot, const Glib::RefPtr< Cancellable >& cancellable, int io_priority=Glib::PRIORITY_DEFAULT)
| Requests an asynchronous close of the stream, releasing resources related to it. More...
void | close_async (const SlotAsyncReady& slot, int io_priority=Glib::PRIORITY_DEFAULT)
| Requests an asynchronous close of the stream, releasing resources related to it. More...
bool | close_finish (const Glib::RefPtr< AsyncResult >& result)
| Closes an output stream. More...
bool | is_closed () const
| Checks if an output stream has already been closed. More...
bool | is_closing () const
| Checks if an output stream is being closed. More...
bool | has_pending () const
| Checks if an ouput stream has pending actions. More...
Public Member Functions inherited from Glib::Object
| Object (const Object&)=delete
Object& | operator= (const Object&)=delete
| Object (Object&& src) noexcept
Object& | operator= (Object&& src) noexcept
void* | get_data (const QueryQuark& key)
void | set_data (const Quark& key, void* data)
void | set_data (const Quark& key, void* data, DestroyNotify notify)
void | remove_data (const QueryQuark& quark)
void* | steal_data (const QueryQuark& quark)
Public Member Functions inherited from Glib::ObjectBase
| ObjectBase (const ObjectBase&)=delete
ObjectBase& | operator= (const ObjectBase&)=delete
void | set_property_value (const Glib::ustring& property_name, const Glib::ValueBase& value)
| You probably want to use a specific property_*() accessor method instead. More...
void | get_property_value (const Glib::ustring& property_name, Glib::ValueBase& value) const
| You probably want to use a specific property_*() accessor method instead. More...
template<class PropertyType >
void | set_property (const Glib::ustring& property_name, const PropertyType& value)
| You probably want to use a specific property_*() accessor method instead. More...
template<class PropertyType >
void | get_property (const Glib::ustring& property_name, PropertyType& value) const
| You probably want to use a specific property_*() accessor method instead. More...
void | connect_property_changed (const Glib::ustring& property_name, const sigc::slot< void >& slot)
| You can use the signal_changed() signal of the property proxy instead. More...
void | connect_property_changed (const Glib::ustring& property_name, sigc::slot< void >&& slot)
| You can use the signal_changed() signal of the property proxy instead. More...
sigc::connection | connect_property_changed_with_return (const Glib::ustring& property_name, const sigc::slot< void >& slot)
| You can use the signal_changed() signal of the property proxy instead. More...
sigc::connection | connect_property_changed_with_return (const Glib::ustring& property_name, sigc::slot< void >&& slot)
| You can use the signal_changed() signal of the property proxy instead. More...
void | freeze_notify ()
| Increases the freeze count on object. More...
void | thaw_notify ()
| Reverts the effect of a previous call to freeze_notify(). More...
virtual void | reference () const
| Increment the reference count for this object. More...
virtual void | unreference () const
| Decrement the reference count for this object. More...
GObject* | gobj ()
| Provides access to the underlying C GObject. More...
const GObject* | gobj () const
| Provides access to the underlying C GObject. More...
GObject* | gobj_copy () const
| Give a ref-ed copy to someone. Use for direct struct access. More...
Public Member Functions inherited from sigc::trackable
| trackable () noexcept
| trackable (const trackable &src) noexcept
| trackable (trackable &&src)
| ~trackable ()
void | add_destroy_notify_callback (void *data, func_destroy_notify func) const
void | notify_callbacks ()
trackable & | operator= (const trackable &src)
trackable & | operator= (trackable &&src)
void | remove_destroy_notify_callback (void *data) const
Public Member Functions inherited from Gio::Seekable
| Seekable (Seekable&& src) noexcept
Seekable& | operator= (Seekable&& src) noexcept
| ~Seekable () noexcept override
GSeekable* | gobj ()
| Provides access to the underlying C GObject. More...
const GSeekable* | gobj () const
| Provides access to the underlying C GObject. More...
goffset | tell () const
| Tells the current position within the stream. More...
bool | can_seek () const
| Tests if the stream supports the SeekableIface. More...
bool | seek (goffset offset, Glib::SeekType type, const Glib::RefPtr< Cancellable >& cancellable)
| Seeks in the stream by the given offset, modified by type. More...
bool | seek (goffset offset, Glib::SeekType type)
| A seek() convenience overload. More...
bool | can_truncate () const
| Tests if the stream can be truncated. More...
bool | truncate (goffset offset, const Glib::RefPtr< Cancellable >& cancellable)
| Truncates a stream with a given #offset. More...
bool | truncate (goffset offset)
| A truncate() convenience overload. More...
Public Member Functions inherited from Glib::Interface
| Interface ()
| A Default constructor. More...
| Interface (Interface&& src) noexcept
Interface& | operator= (Interface&& src) noexcept
| Interface (const Glib::Interface_Class& interface_class)
| Called by constructors of derived classes. More...
| Interface (GObject* castitem)
| Called by constructors of derived classes. More...
| ~Interface () noexcept override
| Interface (const Interface&)=delete
Interface& | operator= (const Interface&)=delete
GObject* | gobj ()
const GObject* | gobj () const

## Static Public Member Functions

static GType | get_type ()
| Get the GType for this class, for use with the underlying GObject type system. More...
Static Public Member Functions inherited from Gio::OutputStream
static GType | get_type ()
| Get the GType for this class, for use with the underlying GObject type system. More...
Static Public Member Functions inherited from Gio::Seekable
static void | add_interface (GType gtype_implementer)
static GType | get_type ()
| Get the GType for this class, for use with the underlying GObject type system. More...

## Related Functions

(Note that these are not member functions.)
Glib::RefPtr< Gio::FileOutputStream > | wrap (GFileOutputStream* object, bool take_copy=false)
| A Glib::wrap() method for this object. More...
Related Functions inherited from Gio::OutputStream
Glib::RefPtr< Gio::OutputStream > | wrap (GOutputStream* object, bool take_copy=false)
| A Glib::wrap() method for this object. More...
Related Functions inherited from Glib::Object
Glib::RefPtr< Glib::Object > | wrap (GObject* object, bool take_copy=false)
Related Functions inherited from Gio::Seekable
Glib::RefPtr< Gio::Seekable > | wrap (GSeekable* object, bool take_copy=false)
| A Glib::wrap() method for this object. More...

## Additional Inherited Members

Public Types inherited from Glib::Object
using | DestroyNotify = void(*)(gpointer data)
Public Types inherited from sigc::trackable
typedef internal::func_destroy_notify | func_destroy_notify
Protected Member Functions inherited from Gio::OutputStream
| OutputStream ()
bool | set_pending ()
| Sets stream to have actions pending. More...
void | clear_pending ()
| Clears the pending flag on stream. More...
Protected Member Functions inherited from Glib::Object
| Object ()
| Object (const Glib::ConstructParams& construct_params)
| Object (GObject* castitem)
| ~Object () noexcept override
Protected Member Functions inherited from Glib::ObjectBase
| ObjectBase ()
| This default constructor is called implicitly from the constructor of user-derived classes, even if, for instance, Gtk::Button calls a different ObjectBase constructor. More...
| ObjectBase (const char* custom_type_name)
| A derived constructor always overrides this choice. More...
| ObjectBase (const std::type_info& custom_type_info)
| This constructor is a special feature to allow creation of derived types on the fly, without having to use g_object_new() manually. More...
| ObjectBase (ObjectBase&& src) noexcept
ObjectBase& | operator= (ObjectBase&& src) noexcept
virtual | ~ObjectBase () noexcept=0
void | initialize (GObject* castitem)
void | initialize_move (GObject* castitem, Glib::ObjectBase* previous_wrapper)
Protected Member Functions inherited from Gio::Seekable
| Seekable ()
| You should derive from this class to use it. More...

## Detailed Description

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

FileOutputStream implements Seekable, which allows the output stream to jump to arbitrary positions in the file and to truncate the file, provided the file system of the file supports these operations. Use the methods of the Seekable base class for seeking and positioning.

Since glibmm 2.16:

## Constructor & Destructor Documentation

## FileOutputStream()

Gio::FileOutputStream::FileOutputStream | ( | FileOutputStream&& | src | ) |

noexcept

## ~FileOutputStream()

Gio::FileOutputStream::~FileOutputStream | ( |  | ) |

override noexcept

## Member Function Documentation

## get_etag()

std::string Gio::FileOutputStream::get_etag | ( |  | ) | const

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.

Returns
  The entity tag for the stream.

## get_type()

static GType Gio::FileOutputStream::get_type | ( |  | ) |

static

Get the GType for this class, for use with the underlying GObject type system.

## gobj() [1/2]

GFileOutputStream* Gio::FileOutputStream::gobj | ( |  | ) |

inline

Provides access to the underlying C GObject.

## gobj() [2/2]

const GFileOutputStream* Gio::FileOutputStream::gobj | ( |  | ) | const

inline

Provides access to the underlying C GObject.

## gobj_copy()

GFileOutputStream* Gio::FileOutputStream::gobj_copy | ( |  | ) |

Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs.

## operator=()

FileOutputStream& Gio::FileOutputStream::operator= | ( | FileOutputStream&& | src | ) |

noexcept

## query_info() [1/2]

Glib::RefPtr<FileInfo> Gio::FileOutputStream::query_info | ( | const Glib::RefPtr< Cancellable >& | cancellable,
|  | const std::string & | attributes = `"*"`
| ) |  |

Queries a file output stream for the given attributes .

This function blocks while querying the stream. For the asynchronous version of this function, see query_info_async(). While the stream is blocked, the stream will set the pending flag internally, and any other operations on the stream will throw a Gio::Error with PENDING.

Can fail if the stream was already closed (with a CLOSED error), the stream has pending operations (with a PENDING error), or if querying info is not supported for the stream's interface (with a NOT_SUPPORTED error). In all cases of failure, an empty RefPtr will be returned.

The operation can be cancelled by triggering the cancellable object from another thread. If the operation was cancelled, a Gio::Error with CANCELLED may be thrown, and an empty RefPtr will be returned.

Parameters

  cancellable | A Cancellable object.
  attributes | A file attribute query string.

Returns
  A FileInfo for the stream, or an empty RefPtr on error.

## query_info() [2/2]

Glib::RefPtr<FileInfo> Gio::FileOutputStream::query_info | ( | const std::string & | attributes = `"*"` | ) |

Queries a file output stream for the given attributes .

This function blocks while querying the stream. For the asynchronous version of this function, see query_info_async(). While the stream is blocked, the stream will set the pending flag internally, and any other operations on the stream will throw a Gio::Error with PENDING.

Can fail if the stream was already closed (with a CLOSED error), the stream has pending operations (with an PENDING error), or if querying info is not supported for the stream's interface (with a NOT_SUPPORTED error). In all cases of failure, an empty RefPtr will be returned.

The operation can be cancelled by triggering the cancellable object from another thread. If the operation was cancelled, a Gio::Error with CANCELLED may be thrown, and an empty RefPtr will be returned.

Parameters

  attributes | A file attribute query string.

Returns
  A FileInfo for the stream, or an empty RefPtr on error.

## query_info_async() [1/2]

void Gio::FileOutputStream::query_info_async | ( | const SlotAsyncReady& | slot,
|  | const Glib::RefPtr< Cancellable >& | cancellable,
|  | const std::string & | attributes = `"*"`,
|  | int | io_priority = `Glib::PRIORITY_DEFAULT`
| ) |  |

Queries the stream information asynchronously.

When the operation is finished slot will be called. You can then call query_info_finish() to get the result of the operation.

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

The operation can be cancelled by triggering the cancellable object from another thread. If the operation was cancelled, a Gio::Error with CANCELLED may be thrown

Parameters

  slot | Callback to call when the request is satisfied.
  cancellable | A Cancellable object.
  attributes | A file attribute query string.
  io_priority | The <io-priority of the request.

## query_info_async() [2/2]

void Gio::FileOutputStream::query_info_async | ( | const SlotAsyncReady& | slot,
|  | const std::string & | attributes = `"*"`,
|  | int | io_priority = `Glib::PRIORITY_DEFAULT`
| ) |  |

Queries the stream information asynchronously.

When the operation is finished slot will be called. You can then call query_info_finish() to get the result of the operation.

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

Parameters

  slot | Callback to call when the request is satisfied.
  attributes | A file attribute query string.
  io_priority | The <io-priority of the request.

## query_info_finish()

Glib::RefPtr<FileInfo> Gio::FileOutputStream::query_info_finish | ( | const Glib::RefPtr< AsyncResult >& | result | ) |

Finalizes the asynchronous query started by g_file_output_stream_query_info_async().

Parameters

  result | A AsyncResult.

Returns
  A FileInfo for the finished query.

## Friends And Related Function Documentation

## wrap()

Glib::RefPtr< Gio::FileOutputStream > wrap | ( | GFileOutputStream * | object,
|  | bool | take_copy = `false`
| ) |  |

related

A Glib::wrap() method for this object.

Parameters

  object | The C instance.
  take_copy | False if the result should take ownership of the C instance. True if it should take a new copy or ref.

Returns
  A C++ instance that wraps this C instance.