Re: pkg_alternatives, Darwin and locale

[Louis Guillaume <lguillaume%berklee.edu@localhost>]

Joerg Sonnenberger wrote:
> On Mon, Jul 21, 2008 at 05:02:08PM -0400, Louis Guillaume wrote:
>
> > +found=$(awk '!/^[      ]*#/{
> > +  f = "if [ -x " $1 " ] ; then echo " $0 " ;fi " | getline found 
> > +  if ( f == 1 ) {
> > +    print found
> > +    exit
> > +  }
> > +}' $files )
> > +
>
> Better, but still better is to use a while loop for the outer part.
> The problem with "while read foo" in shell is that it will do a system
> call per byte. If you can move all the other processing inside awk,
> that is preferable. The test builtin is less expensive than the reading
> though, so
> awk ... | while read prog alternative; do
>         if [ -x "$prog" ]; then
>                 echo $alternative
>                 break
>         fi
> done
>
> or so is most readable and involves the smallest number of forks.
>
> Joerg

So how's about something like ...

awk '!/^[ \t]*#/{ print $1,$0 }' $files | while read prog alt ;do
  [ -x "${prog}" ] && exec ${alt} "${@}"
done

echo "${progname}: no alternatives found" >&2
exit 1