Re: Switching off a shellcommand with empty list variable

[David Baird]

Joe Moore wrote:
> David Baird wrote:
>
> > control:
> >     missing_ports = ( ExecResult(/usr/bin/perl -e blah) )
> >
> > shellcommands:
> >
> >   "/usr/local/sbin/portupgrade --new $(missing_ports)"
> >
> >
> > The perl one-liner returns a colon-separated list of ports that need 
> > to be installed. The problem is that if there are no missing ports, 
> > the shellcommand still gets called. Is there any way I can set a class 
> > if $(missing_ports) is empty?
> Perhaps
>
> shellcommands:
>    "[ -n '$(missing_ports)' ] && /usr/local/sbin/portupgrade --new 
> $(missing_ports)"
>
> --Joe

Thanks! That helps, except that cfengine requires shellcommands to start 
with absolute file paths. Should work if I stick a dummy command like 
/bin/sleep 0 at the start.

d.