Re: Freeze exception request for mythtv-status

[Julien Cristau <jcristau@debian.org>]

On Fri, Nov  7, 2008 at 20:05:02 +0100, Adeodato Simó wrote:

> * Andrew Ruthven [Tue, 04 Nov 2008 14:08:32 +1300]:
> 
> > Gidday,
> 
> Hello,
> 
> > +    # Just incase someone has removed their motd file.
> > +    [ ! -f /var/run/motd ] && touch /var/run/motd
> >      [ ! -f /var/run/motd.orig ] && cp /var/run/motd /var/run/motd.orig
> 
> This is wrong for a `set -e` script. If those files exist, the left part
> of the expression will fail, and the script will abort. The proper way
> to do it is:
> 
>       [ -f /var/run/motd ] || touch /var/run/motd
>       [ -f /var/run/motd.orig ] || cp /var/run/motd /var/run/motd.orig
> 
FWIW, set -e won't abort the script with the above code (well, unless
touch or cp fail).  From dash(1):

     -e errexit       If not interactive, exit immediately if any
                      untested command fails.  The exit status of a com‐
                      mand is considered to be explicitly tested if the
                      command is used to control an if, elif, while, or
                      until; or if the command is the left hand operand
                      of an “&&” or “||” operator.

Cheers,
Julien