dovecot - Mar 2021 - bug: some table header(?) output goes to stderr instead of stdout

On 2021-03-18, Marc <Marc at f1-outsourcing.eu>
wrote:
>
> [@ sbin]# doveadm -f table -o
mail_location=mdbox_deleted:/home/popusers/testtest/mdbox:INDEX=/home/popindex/testtest/index
fetch -u testtest 'guid' mailbox INBOX 2> /dev/null
> 3c967f33b8aea671f3551db1ea8e33e9
> 6fa01ccc103a7009c7b940657dbcd72c
> ba955a6d6218950f42e5b0ee0a33a916
>
> [@ sbin]# doveadm -f table -o
mail_location=mdbox_deleted:/home/popusers/testtest/mdbox:INDEX=/home/popindex/testtest/index
fetch -u testtest 'guid' mailbox INBOX
> guid
> 3c967f33b8aea671f3551db1ea8e33e9
> 6fa01ccc103a7009c7b940657dbcd72c
> ba955a6d6218950f42e5b0ee0a33a916
>
>
>
That's a useful feature, saves messing about to exclude the headers when you
want to use the results to fetch messages as shown in doveadm-search(1).

> On 2021-03-18, Marc <Marc at f1-outsourcing.eu> wrote:
> >
> > [@ sbin]# doveadm -f table -o
> mail_location=mdbox_deleted:/home/popusers/testtest/mdbox:INDEX=/home/po
> pindex/testtest/index fetch -u testtest 'guid' mailbox INBOX 2>
> /dev/null
> > 3c967f33b8aea671f3551db1ea8e33e9
> > 6fa01ccc103a7009c7b940657dbcd72c
> > ba955a6d6218950f42e5b0ee0a33a916
> >
> > [@ sbin]# doveadm -f table -o
> mail_location=mdbox_deleted:/home/popusers/testtest/mdbox:INDEX=/home/po
> pindex/testtest/index fetch -u testtest 'guid' mailbox INBOX
> > guid
> > 3c967f33b8aea671f3551db1ea8e33e9
> > 6fa01ccc103a7009c7b940657dbcd72c
> > ba955a6d6218950f42e5b0ee0a33a916
> >
> >
> >
> 
> That's a useful feature, saves messing about to exclude the headers
when
> you
> want to use the results to fetch messages as shown in doveadm-search(1).
> 
Using stderr/stdout like this is not according to standards. But I do get that,
I was tryig to do that with tail -n +1, and thought wtf is it not working!!! ;)
There could be a nasty side effect, if someone starts redirecting 2>/dev/null
because of this table header. He will not get a real error.

On 2021-03-18, Marc <Marc at f1-outsourcing.eu> wrote:
> [@ sbin]# doveadm -f table -o
mail_location=mdbox_deleted:/home/popusers/testtest/mdbox:INDEX=/home/popindex/testtest/index
fetch -u testtest 'guid' mailbox INBOX 2> /dev/null
> 3c967f33b8aea671f3551db1ea8e33e9
> 6fa01ccc103a7009c7b940657dbcd72c
> ba955a6d6218950f42e5b0ee0a33a916
Strange -- my version (2.3.10) dumps headers to stdout, not stderr

 	# doveadm -f table fetch -u $user guid mailbox INBOX 2>/dev/null | cat -n |
head -3
 	1  guid
 	2  8104226179c70d7cc248c9924cabdb8c
 	3  0813554a7ed4cf1e113f42a4cc8bc477
>From a strictly design point of view, this seems more correct as the
header is part of the data, not "out of band" output like errors.  If
headers
are pumped to stderr, you can always employ shell hacks (as a followup poster
did) to unify them to stdout

 	# doveadm -f table fetch ... 2>&1

Maybe it's better to add another formatter to avoid tricky parsing
or shell hacks e.g.

 	# doveadm -f tab-nohdr ...

Joseph Tam <jtam.home at gmail.com>