Re: expansion in conditional expression patterns

[Peter Stephenson <pws@xxxxxxx>]

Peter Stephenson wrote:
> Sebastian Stark wrote:
> > I just did this:
> > 
> >    if [[ ! ( ($cmdnum -ge 1) && ($cmdnum -le $limit) ) ]]
> > 
> > Maybe I should have asked differently because there might be a better  
> > solution for what I'm trying to do. I have an array of commands,  
> > $cmds, and a user supplied $cmdnum. Now I want to check wether the  
> > user entered a valid number. ($limit would be $#cmds in this example).
> > 
> > Is there a better way to check wether the user entered a) a number and  
> > b) in the range 1..$#cmds?
> 
> I don't think there's anything magic that you're missing.  I'd do
> something like:
> 
>   if [[ $cmdnum != <-> || $cmdnum -gt $#cmds ]]; then
>     # error
>   fi

... except it could be zero, so

if [[ $cmdnum != <1-> || $cmdnum -gt $#cmds ]]; then
    # error
fi

-- 
Peter Stephenson <pws@xxxxxxx>            Software Engineer
Tel: +44 (0)1223 692070                   Cambridge Silicon Radio Limited
Churchill House, Cambridge Business Park, Cowley Road, Cambridge, CB4 0WZ, UK


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