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Re: [PLUG] question re: perl diamond operator
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Hi:
* Edmond Rodriguez <erodrig_97@yahoo.com> [2009-06-25 09:57:24 -0700]:
>
> If you put in two files that don't exist you get two error messages.
>
> If you put in one file that does not exist followed by one that does, it
> still processes the one that does exist. Is it designed to be fail safe for
> this invocation?
>
>
> $ ./example.pl foo foo2
> Can't open foo: No such file or directory at ./example.pl line 3.
> this is foo line 1this is foo line 2
>
> $ echo $?
> 0
Yeah good question... it's funny because the motivation for <> in perl seems
to be to copy the way standard UNIX utils work. E.g.
$ cat file1 file2
... will throw an error about non-existent file1, then proceed to cat the
contents of file2. The perl diamond operator does the same. However, cat
still returns a non-zero exit code in this case. I couldn't find a way to
"test" the diamond operator to easily duplicate this behavior.
But anyway... see my other message for a method that works for me.
> ----- Original Message ----
> > From: Mark M. Hoffman <mhoffman@lightlink.com>
> > To: plug@lists.phillylinux.org
> > Sent: Thursday, June 25, 2009 12:24:20 PM
> > Subject: [PLUG] question re: perl diamond operator
> >
> > Hi all:
> >
> > Given the following trivial script:
> >
> > >> #! /usr/bin/perl -w
> > >>
> > >> while (<>) {
> > >> chomp;
> > >> print $_;
> > >> }
> >
> > $ ./example.pl foo
> > Can't open foo: No such file or directory at ./example.pl line 3.
> >
> > So far so good; the file foo really does not exist.
> >
> > $ echo $?
> > 0
> >
> > Really? I want the exit status to be non-zero here. I've looked through the
> > perl documentation; I can't see any way to get the diamond operator to do what
> > I want in this case. I would appreciate any suggestions from perl experts.
Thanks & regards,
--
Mark M. Hoffman
mhoffman@lightlink.com
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