Re: ls: avoiding error msg on non-existant file

On 2002.11.22 00:36 Bob Proulx wrote:
> Karl O . Pinc <[email protected]> [2002-11-18 14:33:30 -0600]:
> > To keep there error from coming up, I can
> >
> > 2>/dev/null
> >
> > if [ ! -e . ] ; then ls pattern ; fi
> >
> > but niether of these solutions is particularly elegant.
> > The first throws all errors away, and I want to know if
> > there are any other errors.  The second assumes that
> > there will only be files in the directory when the directory
> > also contains files matching <pattern>.

> The first is rather like this.
> 
>   for file in pattern ; do
>     if [ ! -f "$file" ]; then
>       echo "$file: no such file" 1>&2
>     fi
>   done

> You did not really say what you were trying to do.  Therefore it is
> hard to suggest alternatives.

Sorry.

What I am trying to do is take advantage of the pattern expansion
capabilities of the shell.
I want to pipe the result of the shell's pattern expansion to
the remainder of my program, but I don't want to feed the
right side of the pipe a file that doesn't exist, the pattern
expands to iteslf when there's no matching directory entry.
I attempted to use ls as a filter to remove non-existant
pathnames, a task beyond ls.

You are right, I can filter shell pattern expasion with:

   for f in pattern ; do
     if [ -e "$f" ] ; then
       echo "$f"
     fi
   done

I'm just searching for an existance filter command, so I don't
have to code the loop.  'ls -d', which lists files which _do_ exist
just rolled off my fingers. 
I've no compelling reason not to code the loop, just lazyness.

Thanks for the help.

Karl <[email protected]>