How can I make sure that the title of a Terminal tab/window is identical to the command I typed
macOS Catalina (10.15) now uses Zsh, which makes this really easy.
Show the currently running / last run command by disabling auto_title and adding a preexec hook:
# File: ~/.zshrc
DISABLE_AUTO_TITLE="true"
preexec() {
printf "\e]1;${1}\a"
}