Gio.File.replace_readwrite

### Method

# Gio Filereplace_readwrite

since: 2.22

#### Declaration [src]

    GFileIOStream*
    g_file_replace_readwrite (
      GFile* file,
      const char* etag,
      gboolean make_backup,
      GFileCreateFlags flags,
      GCancellable* cancellable,
      GError** error
    )

#### Description [src]

Returns an output stream for overwriting the file in readwrite mode, possibly creating a backup copy of the file first. If the file doesn’t exist, it will be created.

For details about the behaviour, see `g_file_replace()` which does the same thing but returns an output stream only.

Note that in many non-local file cases read and write streams are not supported, so make sure you really need to do read and write streaming, rather than just opening for reading or writing.

Available since: 2.22

#### Parameters

`etag`

  Type: `const char*`

  An optional entity tag for the current `GFile`, or `NULL` to ignore.

  The argument can be `NULL`.
  The data is owned by the caller of the method.
  The value is a NUL terminated UTF-8 string.

`make_backup`

  Type: `gboolean`

  `TRUE` if a backup should be created.

`flags`

  Type: `GFileCreateFlags`

  A set of `GFileCreateFlags`.

`cancellable`

  Type: `GCancellable`

  Optional `GCancellable` object, `NULL` to ignore.

  The argument can be `NULL`.
  The data is owned by the caller of the method.

`error`

  Type: `GError **`

  The return location for a recoverable error.

  The argument can be `NULL`.
  If the return location is not `NULL`, then you must initialize it to a `NULL` `GError*`.
  The argument will be left initialized to `NULL` by the method if there are no errors.
  In case of error, the argument will be set to a newly allocated `GError`; the caller will take ownership of the data, and be responsible for freeing it.

#### Return value

Type: `GFileIOStream`

A `GFileIOStream` or `NULL` on error. Free the returned object with g_object_unref().

The caller of the method takes ownership of the returned data, and is responsible for freeing it.