zsh Tip: Preview (and undo) command line expansions and substitutions

The zsh shortcut ctrl_ reverses changes to the command line, which you can use to test and optionally undo shell expansions before running a command.

For example, type print -- * and press tab.

The * wildcard expands to the names of matching files and directories. Pressing ctrl_ restores the command line to its previous (unexpanded) state.