$ echo $(ls zsh) zsh-5.0.7-175-g7e74495 zsh $ echo $(ls zsh) << up arrow to recall command. zsh-5.0.7-175-g7e74495 zsh $ echo $(ls zsh) zsh-5.0.7-217-g39a6e8a zsh $ echo ls zsh) << up arrow to recall command. zsh: parse error near `)'