an offset, in bytes, which is added to the position specified by @type
the position in the file, which can be %G_SEEK_CUR (the current position), %G_SEEK_SET (the start of the file), or %G_SEEK_END (the end of the file)
Return: %G_IO_ERROR_NONE if the operation was successful.
Deprecated: Use g_io_channel_seek_position() instead.
Sets the current position in the #GIOChannel, similar to the standard library function fseek().