setopt extended_history  # Record timestamp of command in HISTFILE.
setopt hist_expire_dups_first  # Delete duplicates first when HISTFILE size exceeds HISTSIZE.
setopt hist_ignore_dups  # Ignore duplicated commands history list.
setopt hist_ignore_space  # Ignore commands that start with space.
setopt hist_verify  # Show command with history expansion to user before running it.
setopt share_history  # Share command history data.