alias bug on solaris machines

alias bug on solaris machines

[Andy Spiegl]

Hi,

I discovered a very strange behaviour on my solaris machine.
Aliases are treated like global aliases in some cases:

$ zsh -f
% echo $ZSH_VERSION
4.3.2
% alias
run-help=man
which-command=whence
% GREPCOLOR=""
% alias grep="grep $GREPCOLOR"
% echo "foo man bar" >> /tmp/bla
% grep run-help /tmp/bla             
foo man bar

% uname -a
SunOS cms-qs 5.9 Generic_122300-12 sun4u sparc SUNW,Sun-Fire-V240

% cat /etc/release
                      Solaris 9 9/05 HW s9s_u9wos_06b SPARC
           Copyright 2006 Sun Microsystems, Inc.  All Rights Reserved.
                        Use is subject to license terms.
                           Assembled 25 September 2006


Thanks,
 Andy.

-- 
 Great spirits have always encountered violent opposition from
 mediocre minds.   - Albert Einstein

Re: alias bug on solaris machines

[Peter Stephenson]

Andy Spiegl wrote:
> I discovered a very strange behaviour on my solaris machine.
> Aliases are treated like global aliases in some cases:
> 
> $ zsh -f
> % echo $ZSH_VERSION
> 4.3.2
> % alias
> run-help=man
> which-command=whence
> % GREPCOLOR=""
> % alias grep="grep $GREPCOLOR"
> % echo "foo man bar" >> /tmp/bla
> % grep run-help /tmp/bla             
> foo man bar

That's actually expected behaviour.  It's documented that aliases that
end with a space cause the following word to be expanded as an alias.
Since GREPCOLOR is empty, the alias for grep does end with a space.

You ought to do something like

  [[ -n $GREPCOLOR ]] && alias grep="grep $GREPCOLOR"

or

  alias grep="grep${GREPCOLOR:+ $GREPCOLOR}"

-- 
Peter Stephenson <pws@csr.com>                  Software Engineer
CSR PLC, Churchill House, Cambridge Business Park, Cowley Road
Cambridge, CB4 0WZ, UK                          Tel: +44 (0)1223 692070

Re: alias bug on solaris machines - DOH!

[Andy Spiegl]

Hi Peter,

> That's actually expected behaviour.  It's documented ...
That explains it all!  I think I have never read this line in the manpage.

Thanks a lot,
 Andy.

-- 
 As I said before, I never repeat myself!

Re: alias bug on solaris machines

[Bart Schaefer]

On Dec 20,  2:05pm, Peter Stephenson wrote:
} Subject: Re: alias bug on solaris machines
}
} That's actually expected behaviour.  It's documented that aliases that
} end with a space cause the following word to be expanded as an alias.
} Since GREPCOLOR is empty, the alias for grep does end with a space.
} 
} You ought to do something like
} 
}   [[ -n $GREPCOLOR ]] && alias grep="grep $GREPCOLOR"

Or just

    alias grep='grep $GREPCOLOR'

(single quotes) which would wait to expand the variable until the time
grep is run, which seems more like what you'd want anyway.