Flush Left All Lines in Buffer

I use this dinky little macro all the time. Offered for your consideration ... and, as always, perhaps you can build on it

// flush left all lines in current buffer
// TODO: Add option to affect line, selection, or all
// depending on select_active, etc

_command fl,flush_left_all() name_info(','VSARG2_REQUIRES_EDITORCTL)
{
save_pos(p);
top();
search('^:b','r*','');
restore_pos(p);
}