[ILUG] perl subroutine params

[John Gaughan]

On Thu, 09 May 2002, Gavin McCullagh wrote:
> Hi,
> 
> if I write a perl script and in it a subroutine like 
> 
> #!/usr/bin/perl -w
> 
> use diagnostics;
> use strict;
> 
> &some_subroutine("1","2","3");
> 
> sub some_routine ($$$) {
> 	print "$_[0]\t$_[1]\t$_[2]\n";
> }
> 
> 
> It ws my understanding that if I called the subroutinewith anything other
> than three scalar variables, I should get a complaint.  However I tried it
> out with {0,1,2,4} params and it just works on regardless.
> 
> Am I doing something wrong?  Do I need to tell perl to enforce this?

It's because you're calling the subroutine with an "&" prefix.  This
causes the the argument list to become optional, and prototype checking
is also disabled.  For a bit more detail see the perlsub manpage, it's
described before the section on private variables[1].

John.

  1. http://perldoc.com/perl5.005_03/pod/perlsub.html#Private-Variables-via-my()
-- 
John Gaughan, Systems Administrator
Irish Times New Media - http://www.ireland.com/