void gtk_text_buffer_get_iter_at_line ( GtkTextBuffer* buffer, GtkTextIter* iter, gint line_number )
iter to the start of the given line. If
line_number is greater
than the number of lines in the
buffer, the end iterator is returned.
Iterator to initialize.
The argument will be set by the function. The data is owned by the instance.
Line number counting from 0