From: Daniel Berger <djberg96@...>
Date: 2005-05-14T10:30:29+09:00
Subject: Re: Customing the Exception class

Eric Hodel wrote:
> On 13 May 2005, at 14:35, Ara.T.Howard@noaa.gov wrote:
>
> > On Sat, 14 May 2005, Daniel Berger wrote:
> >
> >
> >> Hi all,
> >>
> >> I have a program where I want to send all errors to a file.  So, I

> >> did this:
>
> [snip]
>
> >> This works for most errors, but it doesn't seem to work when the
> >> error
> >> is a SystemCallError.
> >>
> >> For example, this writes to the log as expected:
> >>
> >> print "Some crazy division: "
> >> p 1/0
> >>
> >> But this does not:
> >>
> >> File.open("non-existant file")
> >>
> >> The latter raises an Errno::ENOENT.
> >>
> >> Why, if SystemCallError is a subclass of Exception, does my
> >> approach not
> >> work?  How do I make this work as expected?
> >
> > maybe new?
>
> [snip]
>
> > not sure why...
>
> SystemCallError does not use Exception's initialize:
>
>      rb_eSystemCallError = rb_define_class("SystemCallError",
> rb_eStandardError);
>      rb_define_method(rb_eSystemCallError, "initialize",
> syserr_initialize, -1);

Yuck.  Could it be altered to call super?  Or would that cause some
hideous side effect?

Regards

Dan

PS - Sorry if this is a double post - google groups went goofy on me
for a minute.