since: 2.34


g_input_stream_read_bytes (
  GInputStream* stream,
  gsize count,
  GCancellable* cancellable,
  GError** error


Like g_input_stream_read(), this tries to read count bytes from the stream in a blocking fashion. However, rather than reading into a user-supplied buffer, this will create a new GBytes containing the data that was read. This may be easier to use from language bindings.

If count is zero, returns a zero-length GBytes and does nothing. A value of count larger than G_MAXSSIZE will cause a G_IO_ERROR_INVALID_ARGUMENT error.

On success, a new GBytes is returned. It is not an error if the size of this object is not the same as the requested size, as it can happen e.g. near the end of a file. A zero-length GBytes is returned on end of file (or if count is zero), but never otherwise.

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. If an operation was partially finished when the operation was cancelled the partial result will be returned, without an error.

On error NULL is returned and error is set accordingly.

Available since: 2.34



Type: gsize

Maximum number of bytes that will be read from the stream. Common values include 4096 and 8192.


Type: GCancellable

Optional GCancellable object, NULL to ignore.

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

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 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: GBytes

A new GBytes, or NULL on error.

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