Question

Why can I do this in zsh:

zsh$ sleep 5 &; echo foo
[1] 14742
foo

but not in bash?

bash$ sleep 5 &; echo foo
bash: syntax error near unexpected token `;'

Is there any way to do the equivalent in bash?

Answer 1

I don’t normally use zsh, but this seems to be equivalent:

sleep 5 & echo foo

It also works in zsh.

I checked zsh documentation and don’t see any special meaning to the combination &;. This seems to be just a background command followed by an empty command, which gets ignored. bash, on the other hand, doesn’t allow empty commands; you get the same error if you type:

; echo foo