Date: Wed, 30 Jun 2004 12:49:22 -0500 From: Josh Paetzel <friar_josh@tcbug.org> To: Drew Tomlinson <drew@mykitchentable.net> Cc: Steve Bertrand <steveb@eagle.ca> Subject: Re: Perl Syntax Message-ID: <20040630174921.GA11187@ns1.tcbug.org> In-Reply-To: <40E2F5B9.305@mykitchentable.net> References: <40E2EF7E.3000901@mykitchentable.net> <4769.209.167.16.15.1088615085.squirrel@209.167.16.15> <40E2F5B9.305@mykitchentable.net>
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> >>I'm using perl 5.8.4 on a 4.9 machine. I want to add code a perl script
> >>to check for value passed from command line. If it is null, I want to
> >>exit with an error message.
> >>
> >>First I tried this and got "Use of uninitialized value in string eq at
> >>./test.pl line 20."
> >>
> >>if ($ARGV[0] eq "") {
> >> print "You must include the file name.";
> >> exit 1;
> >>}
> >>
> >>Next I tried this but get "Use of uninitialized value in length at
> >>./test.pl line 20."
> >>
> >>if (length ($ARGV[0]) = "0") {
> >> print "You must include the file name.";
> >> exit 1;
> >>}
> >>
> >>I've searched the web and all examples that I've found indicate that I'm
> >>doing things correctly but obviously I'm not. What am I doing wrong?
> >>
> >>
> >>
> >
> >I know this works:
> >
> >if ($ARGV[0] eq '') {
> > print "Debug Mode\n";
> >}
> >
> >Cheers,
> >
> >Steve
> >
> Thanks for your reply. I tried your suggestion and it seems to work but
> I get this output:
>
> Use of uninitialized value in string eq at ./test.pl line 16.
> You must include the file name.
>
> I have "use warnings;" and "use strict;" in the script. I assume the
> error comes from the "use warnings;" but why does perl see "eq" as a
> string and not an operator? Or am I misinterpreting the message?
>
> Thanks,
>
> Drew
>
#!/usr/bin/perl -w
if (!ARGV[0]) {
print "no arguements\n";
}
else {
print "found an arguement\n";
}
Josh Paetzel
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