my $v="toto";
change( $v);
print $v;
sub change { $_[0]="tata"; }
##</code><code>##

sub my_print
  { if(UNIVERSAL::isa($_[0], 'GLOB' )) 
      { my( $fh, $text)= @_;
        print $fh "my", $text;
      }
    else
      { print "my", $text; }
  }
##</code><code>##

#!/bin/perl -w
use strict;
my $s="toto";
my $n="3";
append( $s, "one");
append( $n, 1);
print "s: $s  n: $n\n";
 
sub append
  { if( $_[1]=~ /^\d+$/) { &append_nb; }
    else                 { &append_string; }
  }
sub append_string
  { $_[0] .= $_[1]; }
sub append_nb
  { $_[0] += $_[1]; }