From: Austin Ziegler <austin@...>
Date: 2002-12-06T22:15:15+09:00
Subject: Re: on error resume next

On Fri, 6 Dec 2002 22:02:39 +0900, Shannon Fang wrote:

Shannon -- I recommend that you start putting spaces around your
symbols (e.g., f.class!=File COULD be interpreted as f.class! = File
and not f.class != File).

> conn = tcpserver.connect(remote)
> if conn==nil then
>   #some problem with connection
>   exit
> end

conn = tcpserver.connect(remote) rescue conn = nil
if conn.nil? then
  # some problem with connection
  exit
end

> f=File.open(testfile)
> if f.class!=File then
>   #cannot open file
>   #do something with it
> end

f = File.open(testfile) rescue f = nil
if f.nil? then
  # cannot open file
  # do something with it
end

This form of rescue won't work on all exception types, but it will
catch a good majority of them. You could also make it so that the
rescue calls a method and then checks $! (the global exception
object) to determine the exact response, but that only hides your
normal begin/rescue/end handling.

-austin
-- Austin Ziegler, austin@halostatue.ca on 2002.12.06 at 08.11.34