Re: [vox-tech] bash question

[Peter Jay Salzman <p@diraMAPSc.org>]

On Mon 16 Apr 01,  1:12 PM, Micah Cowan said: 
> On Mon, Apr 16, 2001 at 12:51:02PM -0700, William Kendrick wrote:
> > I'm trying to write a simple shell script which takes in a list of
> > arguments and then picks one randomly and spits it out.
> > 
> > In otherwords, if you run:
> > 
> >   ./random.sh Hello World How Are You
> > 
> > You will sometimes get the word "Hello", sometimes "You", sometimes "How", etc.
> > 
> > 
> > Picking the random number is pretty simple:
> > 
> > 
> >   PICK=`expr $RANDOM % $#`
> > 
> > (pick an entirely random number, and then MOD it by the number of arguments
> > sent to the program, thus getting a number between 0 and num_args - 1)
> 
> Bill, the following:
> 
> ------------------------
> #!/bin/bash
> 
> declare -a my_array
> my_array=("$@")
> 
> element_to_print=$(( $RANDOM * ${#my_array[@]} / 32767 ))
> 
> echo "${my_array[$element_to_print]}"
> ------------------------
> 
> Works for me.  This relies on arrays, so notice that this won't work
> on older bash's.  There may well be another way to do this that
> doesn't rely on arrays, but this works for me.
 
bill, here's a MUCH simpler method:

var=2
shift $var
echo $1        <-- $1 now holds the var'th command line argument.


arguments start at 0, so var=0 corresponds to the first argument.

nice short lines.  simple.

pete