On Tue, Apr 17, 2012 at 9:43 AM, Gary Stainburn
<gary.stainb...@ringways.co.uk> wrote:
> On Tuesday 17 April 2012 13:30:59 Manfred Lotz wrote:
>>
>> One example is this:
>>
>> #! /usr/bin/perl
>>
>> use strict;
>> use warnings;
>>
>> mysub;
>>
>> sub mysub {
>> print "Hi there\n";
>> }
>>
>> If you run this you get an error:
>> Bareword "mysub" not allowed while "strict subs" in use at ./testsub.pl
>> line 6. Execution of ./testsub.pl aborted due to compilation errors.
>>
>>
>> Perl tells you that it has no idea what you mean when you use the
>> bareword mysub.
>>
>>
>> Now you have two options to solve it.
>>
>> 1. &mysub;
>>
>> Using the sigil & you tell Perl that mysub is a subroutine.
>>
>> 2. mysub();
>>
>> Usind () after mysub you also tell Perl that mysub is a subroutine.
>>
>>
>> 3. &mysub();
>>
>> Combining 1. and 2. works also but is not recommended. Hmm, at least I
>> do no recommend it.
>>
>>
>> Use 2. and you'll be happy.
>>
>>
>> There are surely some other situations where using & might be
>> appropriate. But this one came into my mind immediately.
>>Hi Manfred,
>
> Thank you for this, but below is what I am meaning.
>
> Gary
>
> [root@stan ~]# cat t.pl
> #!/usr/bin/perl -w
>
> use strict;
> use warnings;
>
>
> mysub();
>
>
> sub mysub() {
> print "hello world\n";
> }
> [root@stan ~]# ./t.pl
> main::mysub() called too early to check prototype at ./t.pl line 7.
> hello world
>
> }
>
> --
> Gary Stainburn
> Group I.T. Manager
> Ringways Garages
> http://www.ringways.co.uk
>
You are forcing the procedure mysub to use a prototype by including
the empty parameter list. You usually do not want to use prototypes.
Just define mysub without a prototype:
sub mysub {
print "hello world\n";
}
HTH, Ken
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