On Thu, 26 Apr 2007, Dejan Muhamedagic wrote:
> On Thu, Apr 26, 2007 at 10:00:10AM +0200, Andrew Beekhof wrote:
> > On 4/26/07, Simon Horman <[EMAIL PROTECTED]> wrote:
> > >----- Forwarded message from Simon Horman <[EMAIL PROTECTED]> -----
> > >
> > >[...]
> > >On Fri, Apr 20, 2007 at 08:38:59PM +0200, Erich Schubert wrote:
> > >> Package: heartbeat-2
> > >> Version: 2.0.7-2
> > >> Severity: normal
> > >>
> > >> The IPAddr2 script contains bashisms.
> > >> /usr/lib/ocf/resource.d/heartbeat/IPaddr2:
> > >>
> > >>
> > >IF_MAC=${IF_MAC:0:2}:${IF_MAC:2:2}:${IF_MAC:4:2}:${IF_MAC:6:2}:${IF_MAC:8:2}:${IF_MAC:10:2}
> > >>
> > >> Hotfix: replace /bin/sh in the first line by /bin/bash
> > >> Other scripts might be affected as well.
> > >
> > >Thanks, I'll get this fixed. Please let me know if you find any more.
> >
> > i'll push up a fix momentarily
>
> Since IPaddr2 is Linux specific, I guess it's OK to have it run by
> bash.
Executive summary of what follows: a cautious agreement with that:
"Since IPaddr2 is Linux specific, I guess it's OK to have ... bash."
Now the waffle: feel free to hit delete:
A personal view (coming from a portability angle and a Solaris angle):
In general, I would usually argue for Bourne-only, avoiding bash where
reasonably possible, in line with GNU portability recommendations.
But if IPaddr2 really is Linux specific then I'd be OK with bash in this
defined instance, if it makes the insides of the script significantly
cleaner and clearer (more understandable and more maintainable).
The GNU portability purists would argue for Bourne, and discourage bash,
based on the fact that every UN*X-like OS has Bourne, but only some have
bash. Personally, I try to follow that where reasonably possible, to keep
things portable, including in heartbeat.
As a counter-example: They would also argue against using shell functions
because (apparently) some Bournes lack them. Personally, I don't bother
following that one, including in heartbeat, because most "real world"
Bournes these days seem to have shell functions. Indeed, I've added some
myself to heartbeat down the years (and in an email earlier this week, I
suggested adding another).
Solaris? When I started with heartbeat, Solaris versions of the time
lacked native bash. These days, Solaris distributions include bash,
(although not necessarily within the default installation set but at least
these days it's easily installable).
So in the heartbeat context nowadays, I would usually continue to advise
against bash-isms where reasonably possible (for OSes that may still lack
native (or natively available) bash) but in favour of shell functions
(because they tend to add significant clarity, with no apparent loss to
likely OSes). In the case of a known Linux-only script, then bash is
probably OK if its use adds value (clarity, maintainability, etc.).
(Hope you don't mind that rambling piece of background waffle!)
--
: David Lee I.T. Service :
: Senior Systems Programmer Computer Centre :
: UNIX Team Leader Durham University :
: South Road :
: http://www.dur.ac.uk/t.d.lee/ Durham DH1 3LE :
: Phone: +44 191 334 2752 U.K. :
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