- * GFileOutputStream implements #GSeekable, which allows
- * the output stream to jump to arbitrary positions in the 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().