getopts

[Anthony J. Gabrielson]

That worked!

Thanks,
Anthony

On Wed, 30 Jan 2002, Lars Kellogg-Stedman wrote:

> > #!/bin/sh
> > #
> > #       Handles Arguments
> > #
> > 
> > while getopts xy: option
> 
> The first problem is with you optstring.  If both the 'x' and 'y' 
> options require an argument (which is what your help text implies), then 
> your optstring should be 'x:y:'.
> 
> > echo $OPTARG
> 
> What's this echo statement doing in the expression portion of your while 
> statement?  I think you meant for this to come after the 'do' on the 
> next line.  The way its current positioned, your while statement looks 
> like this:
> 
>    while true; do
> 
> Which would loop forever, except that getopts sets option to '?' if 
> there are no more arguments, so instead it bails out in your case statement.
> 
> > do
> >         case $option in
> >                 x) xdim=$OPTARG;;
> >                 y) ydim=$OPTARG;;
> >                 \?) echo "usage: ds9sh [-x columns] [-y columns] file..."
> >                 exit 2;;
> >         esac
> > done
> > shift `expr $OPTIND - 1`
> 
> This ought to work for you:
> 
>    while getopts x:y: option; do
>      case $option in
>        x) xdim=$OPTARG;;
>        y) ydim=$OPTARG;;
>        \?) echo "usage: ..."
>            exit 2;;
>      esac
>    done
>    shift `expr $OPTIND - 1`
> 
> Note that I've replaced some EOLs with semicolons, which is just my 
> formatting preference.  The following two statements are equivalent:
> 
>    while true; do
>      echo hello
>    done
> 
> And:
> 
>    while true
>    do
>      echo hello
>    done
> 
> -- Lars
> 
>