pop - is there a more elegant solution

pop - is there a more elegant solution

[jarausch]

Hello,

just being curious,
is there a more elegant (less cryptic) solution to

#!/bin/zsh
# get the last parameter and shorten the list
# emulate Perl's pop function
echo $@
last=$[-1]
# shorten the parameter array
set $@[0,$[-1+$#]]
echo $@

Thanks for your opinion,


Helmut Jarausch

-- 
Helmut Jarausch
Lehrstuhl fuer Numerische Mathematik
Institute of Technology, RWTH Aachen
D 52056 Aachen, Germany

Re: pop - is there a more elegant solution

[Sven Wischnowsky]

jarausch@igpm.rwth-aachen.dejarausch@igpm.rwth-aachen.de wrote:

> Hello,
> 
> just being curious,
> is there a more elegant (less cryptic) solution to
> 
> #!/bin/zsh
> # get the last parameter and shorten the list
> # emulate Perl's pop function
> echo $@
> last=$[-1]
> # shorten the parameter array
> set $@[0,$[-1+$#]]
> echo $@
> 
> Thanks for your opinion,

Not much less cryptic:

  last="$argv[-1]"
  argv[-1]=()


Bye
  Sven


-- 
Sven Wischnowsky                         wischnow@informatik.hu-berlin.de

Re: pop - is there a more elegant solution

[Bart Schaefer]

On Jun 28, 10:01am, jarausch@igpm.rwth-aachen.de wrote:
}
} is there a more elegant (less cryptic) solution to
} # emulate Perl's pop function

Depends on what you intend by emulating it.  Functions in Bourne-like
shell languages don't return values like functions in perl, so there
isn't anything well-defined to do with the popped value.

The fastest way to simply discard the last positional parameter is

    argv[-1]=()

(which of course only works in zsh).  So if what you want to do is to
store that positional parameter in $last and then discard it,

    last=$argv[-1]
    argv[-1]=()

is about as un-cryptic as you're going to get.

} #!/bin/zsh
} # get the last parameter and shorten the list
} echo $@
} last=$[-1]

You must mean $@[-1].  $[-1] is just -1.  But if you know about $@[-1],
then ...

} # shorten the parameter array
} set $@[0,$[-1+$#]]

... you should know that $@[1,-2] works as well.  (You don't index from
zero unless the ksh_arrays option is set.)

Aside to zsh-workers:  A weird thing about `setopt ksharrays' is that
${@[0]} is $1.  Does ksh really work that way?

-- 
Bart Schaefer                                 Brass Lantern Enterprises
http://www.well.com/user/barts              http://www.brasslantern.com

Zsh: http://www.zsh.org | PHPerl Project: http://phperl.sourceforge.net