> -----Original Message-----
> From: JupiterHost.Net [mailto:[EMAIL PROTECTED]
> Sent: Thursday, December 02, 2004 7:15 PM
> To: [EMAIL PROTECTED]
> Subject: Re: using $! for die()ing with Package function
>
>
>
>
> Paul Johnson wrote:
>
> > On Thu, Dec 02, 2004 at 05:59:49PM -0600, JupiterHost.Net wrote:
> >
> >
> >>if I make a module, say Foobar.pm how do you make it so if a function
> >>returns false you can die $!; ?
> >
> >
> > You can't. Or at least not in the sense you want.
> >
> > $! is linked to the current value of errno, which will be set in the
> > underlying C libraries. Its value is undefined except for just after an
> > error has occurred. errno is an int (or it can be thought of as one).
> > When you use $! in a numeric context you get the value of errno. When
> > you use $! in a string context you get the text associated with that
> > error number.
> >
> > It is possible to assign a numeric value to $!, after which $! in a
> > string context will return the text for the error number you assigned,
> > but this is rarely useful, and certainly not the general way you are
> > looking for.
> >
> > Unfortunately perl doesn't have a standard way of coping with this other
> > than using die, eval {} and $@, which might be seen as overkill in some
> > situations.
> >
> > Take a look at $! in perldoc perlvar.
>
> Will do thanks for the info ;p
>
> I think as long as a failed open() or mkdir() (IE a system function that
> does $! sets it already) then that is all I need for this project:
>
> sub baz {
> mkdir '/dir/I/cant/make' or return;
> }
>
> will do what i need:
>
> baz or die $!;
Actually mkdir returns true or false -
sub baz{return mkdir '/dir/I/cant/make';}
would do the same without any evaluation.
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