How to trap to script EXIT instead of function EXIT?

How to trap to script EXIT instead of function EXIT?

[Peng Yu]

Hi,

The following example shows that `trap` inside a function is trapped
to the function. This behavior is different from bash. Is there a way
to make it the same as bash?

$ cat main.sh
#!/usr/bin/env zsh
# vim: set noexpandtab tabstop=2:

set -v
function f {
	trap "echo 'Hello World!'" EXIT
	trap
}
f
trap
$ ./main.sh
function f {
	trap "echo 'Hello World!'" EXIT
	trap
}
f
trap -- 'echo '\''Hello World!'\' EXIT
Hello World!
trap

$ cat ./main.bash
#!/usr/bin/env bash
# vim: set noexpandtab tabstop=2:

set -v
function f {
	trap "echo 'Hello World!'" EXIT
	trap
}
f
trap
$  ./main.bash
function f {
	trap "echo 'Hello World!'" EXIT
	trap
}
f
trap -- 'echo '\''Hello World!'\''' EXIT
trap
trap -- 'echo '\''Hello World!'\''' EXIT
echo 'Hello World!'
Hello World!

-- 
Regards,
Peng

Re: How to trap to script EXIT instead of function EXIT?

[Bart Schaefer]

On Sun, Dec 2, 2018 at 8:10 PM Peng Yu <pengyu.ut@gmail.com> wrote:
>
> The following example shows that `trap` inside a function is trapped
> to the function. This behavior is different from bash. Is there a way
> to make it the same as bash?

setopt posixtraps

Or more generally, "emulate sh".

Re: How to trap to script EXIT instead of function EXIT?

[Peng Yu]

On Mon, Dec 3, 2018 at 1:41 AM Bart Schaefer <schaefer@brasslantern.com> wrote:
>
> On Sun, Dec 2, 2018 at 8:10 PM Peng Yu <pengyu.ut@gmail.com> wrote:
> >
> > The following example shows that `trap` inside a function is trapped
> > to the function. This behavior is different from bash. Is there a way
> > to make it the same as bash?
>
> setopt posixtraps
>
> Or more generally, "emulate sh".

Thanks.

If function f1 calls function f2, I want to call trap in f2 which
actually set the trap for f1. Is it possible?

-- 
Regards,
Peng

Re: How to trap to script EXIT instead of function EXIT?

[Peter Stephenson]

On Mon, 2018-12-03 at 08:05 -0600, Peng Yu wrote:
> If function f1 calls function f2, I want to call trap in f2 which
> actually set the trap for f1. Is it possible?

Obviously, this is incompatible with the POSIX-style trap usage.


f1() {
  f2() {
    trap 'trap '\''print Was in $lastfunc'\'' EXIT' EXIT 
    lastfunc=f2
  }
  f2
  lastfunc=f1
}


You can neaten this with a bit of variable syntax...


1() {
  f2() {
    local -a trap=(trap 'print Was in $lastfunc' EXIT)
    trap=(${(q)trap})
    trap "$trap" EXIT
    lastfunc=f2
  }
  f2
  lastfunc=f1
}


pws