How to run a second command when the first command fails? e.g., tmux attach || tmux

[jcjolley]

In other shells, I would run tmux attach || tmux to resume a tmux session if one exists, or create one if it doesn't.

I crawled the docs and couldn't find an equivalent to this.
I read #740 and #1352, but neither of them addressed the OR case.

[fdncred]

you are correct. i don't believe we support it yet, but we want to.

[DominicDams]

I think a work around is using an if and complete
i.e.

if ((tmux attach | complete | get exit_code) == 1) {
    tmux
}

But I agree this functionality would be nice

[dheater]

I started work on this so I'll go ahead and post a draft MR #6374

I've only got some initial parsing done. I've not figured out how to break the commands into conditionally executed blocks.

[fdncred]

Semi colon works now like command;command2

[dheater]

Semi colon works now like command;command2

Yes, but that doesn't provide shortcut semantics so there is not a convenient way to do something like if file exists foo && ./foo.