Re: script(1) bug?

[Valery Ushakov <uwe%stderr.spb.ru@localhost>]

On Fri, Aug 28, 2026 at 10:15:04 +0200, Thomas Klausner wrote:

> jq has set up a NetBSD runner on github (i.e. using qemu) and reports
> a weird problem in script: When the command returns too quickly, the
> output file is empty.
> 
> https://github.com/jqlang/jq/pull/3600#issuecomment-5449885827
> 
> I can't reproduce this on my (bare-metal) machine, can someone please
> try to reproduce it?
> 
> for i in $(jot 100); do
>     : > typescript
>     script -qc echo > /dev/null
>     [ ! -s typescript ] && echo ERROR
> done | uniq -c

Ah, we are probably trying to reproduce it wrong.  script behaves
differently when stdin is not a terminal, as RTFS suggests.  And
indeed: consider

  runme() {
    rm typescript
    script -q -f -c 'echo foo; sleep 10;' < /dev/null > /dev/null
    ls -l typescript
    hexdump -C typescript
  }


And then you race:

$ runme
-rw-r--r--  1 uwe  uwe  5 Aug 28 13:44 typescript
00000000  66 6f 6f 0d 0a                                    |foo..|
00000005
$ runme
-rw-r--r--  1 uwe  uwe  0 Aug 28 13:46 typescript
$runme
-rw-r--r--  1 uwe  uwe  0 Aug 28 13:44 typescript
00000000  66 6f 6f 0d 0a                                    |foo..|
00000005


-uwe