Re: wrong shell trap - Mailing list pgsql-hackers

From Tom Lane
Subject Re: wrong shell trap
Date
Msg-id 2379053.1663102893@sss.pgh.pa.us
Whole thread Raw
In response to wrong shell trap  (Alvaro Herrera <alvherre@alvh.no-ip.org>)
Responses Re: wrong shell trap
List pgsql-hackers
Alvaro Herrera <alvherre@alvh.no-ip.org> writes:
> While messing with the new guc.h stuff I happened run headerscheck and
> wanted to abort it right away, and in doing so I realized that its
> 'trap' line is incorrect: it only removes its temp dir, but it doesn't
> exit the program; so after you C-c it, it will spew a ton of complaints
> about its temp dir not existing.

Ugh.

> AFAICT almost all of our shell scripts contain the same mistake.  I
> propose to fix them all as in the attached demo patch, which makes
> headerscheck exit properly (no silly noise) when interrupted.

Sounds like a good idea.

> (I confess to not fully understanding why every other trap does
> "rm && exit $ret" rather than "rm ; exit", but I guess rm -fr should not
> fail anyway thus this should OK.)

I didn't write these, but I think the idea might be "if rm -rf
fails, report its error status rather than whatever we had before".
However, if that is the idea then it's wrong, because as you've
discovered we won't exit at all unless the trap string does so.
So ISTM that 'ret=$?; rm -rf $tmp; exit $ret' is the correct coding,
or at least less incorrect than either of these alternatives.

            regards, tom lane



pgsql-hackers by date:

Previous
From: Nathan Bossart
Date:
Subject: Re: postgres_fdw hint messages
Next
From: Peter Geoghegan
Date:
Subject: Re: wrong shell trap