Getting the Vim exit code value (v:exiting)

[Yegappan Lakshmanan]

Hi all,

Neovim has support for getting the Vim exit code using the

v:exiting variable:

https://github.com/neovim/neovim/pull/5651

This is useful with the VimLeavePre and VimLeave autocommands.

Vim usually exits with exit code 0 or 1. But a user can use the ":cquit"

command to exit with different values. Should we port this to Vim?

Thanks,

Yegappan

[Bram Moolenaar]

I suppose it could be useful for the autocommands.
The help isn't very clear about when the value is valid.
There are four autocommand events related to exiting.
How about "QuitPre" ?

Also, v:exiting suggests it's a flag about whether Vim will exit.
But the help says it's the exit value. Shouldn't it be v:exitvalue
then?

There are situations where Vim may exit, but it is cancelled (when using
a prompt or dialog). What happens then?

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[Yegappan Lakshmanan]

Hi Bram,

On Wed, Nov 25, 2020 at 1:08 PM Bram Moolenaar <Br...@moolenaar.net> wrote:

Yegappan Lakshmanan wrote:

> Neovim has support for getting the Vim exit code using the
> v:exiting variable:
>
> https://github.com/neovim/neovim/pull/5651
>
> This is useful with the VimLeavePre and VimLeave autocommands.
> Vim usually exits with exit code 0 or 1. But a user can use the ":cquit"
> command to exit with different values. Should we port this to Vim?

I suppose it could be useful for the autocommands.
The help isn't very clear about when the value is valid.
There are four autocommand events related to exiting.
How about "QuitPre" ?

It looks like the v:exiting variable is set only for the VimLeavePre

and VimLeave autocmds. For the QuitPre and ExitPre autocmds,

the value is set to v:null.

 

Also, v:exiting suggests it's a flag about whether Vim will exit.
But the help says it's the exit value.  Shouldn't it be v:exitvalue
then?

I agree. It should be named as v:exitvalue or v:exitval. But then it

will be different from NeoVim and the plugin authors need to handle

the difference.

 

There are situations where Vim may exit, but it is cancelled (when using
a prompt or dialog).  What happens then?

In these cases, the VimLeavePre and VimLeave autocmds are not invoked.

The v:exiting value is set to a number only when the VimLeavePre and

VimLeave autocmds are invoked.

- Yegappan

 

[Bram Moolenaar]

Would be good to add all this to the help.

I suppose there is no good reason to do this differently than neovim,
unless some have made remarks it's not good enough.

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DEAD PERSON: I'm not!

[Yegappan Lakshmanan]

We can keep the same name (v:exiting). But one thing I noticed is the

type of this variable. Initially the type of the variable is "Special" and

the value is v:null. When exiting Vim, the type is changed to "Number"

and the value is an integer (exit code). Will changing the variable type

from Special to Number cause a problem?

- Yegappan

[Bram Moolenaar]

Yeah, I don't like that very much. It's like a language where a number
is an Object, so it can be null to indicate it wasn't set. But in Vim
we have real numbers, so it doesn't fit well.

Using -1 for "not set" works better. But then it's different from
neovim...


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