.sh check for numeric content

[Chip Camden]

On Jun 24 05:08, Jerry wrote:
> On Wed, 23 Jun 2010 23:32:57 -0400 (EDT)
> Karl Vogel <vogelke+unix at pobox.com> articulated:
> 
> 
> > >> On Thu, 24 Jun 2010 09:24:39 +0800, 
> > >> Aiza <aiza21 at comclark.com> said:
> > 
> > A> Receiving a variable from the command line that is suppose to
> > A> contain numeric values.  How do I code a test to verify the
> > A> content is numeric?
> > 
> >    The script below will work with the Bourne or Korn shell.
> >    Results for "0 1 12 1234 .12 1.234 12.3 1a a1":
> > 
> >      0 is numeric
> >      1 is numeric
> >      12 is numeric
> >      1234 is numeric
> >      .12 is numeric
> >      1.234 is numeric
> >      12.3 is numeric
> >      1a is NOT numeric
> >      a1 is NOT numeric
> 
> I had used this snippet in a script to test for numeric input. It was
> part of a function in a Bash script.
> 
> case "${1}" in
>   [[:digit:]] )
>     IS_DIGIT=1
>   ;;                                                                                      
>   * )                                                                                     
>     IS_DIGIT=0                                                                            
> printf "\n\a\t   *****WARNING*****                                                        
> \tYou must enter a digit\n\n"                                                             
>   ;;                                                                                      
> esac

That [[:digit:]] pattern only works if your shell supports POSIX
character classes in the case statement.
> 
> -- 
> Jerry ???
> FreeBSD.user at seibercom.net
> 
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Sterling (Chip) Camden
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