_glh_show_history
status = _glh_show_history(gl->glh, _io_write_stdio, fp, fmt, all_groups,
_glh_show_history(gl->glh, gl_write_fn, gl, "%N %T %H\r\n", 0,
int _glh_show_history(GlHistory *glh, GlWriteFn *write_fn, void *data,