warnings, caller, wantarray, ref, $#_

Miscellany example from a Well House Consultants training course
More on Miscellany [link]

This example is described in the following article(s):
• Further more advanced Perl examples - [link]

Source code: waw Module: P303

# warnings, caller, wantarray, ref, $#_

{
package eggs;

sub yolk () { # () says MUST not have any params passed in
@stuff = (5,8,7,6);
$thing = 77;
%what = (17,65,44,33);

$x = demo(16,77);
print ("$x \n");
@y = demo("hello");
print ("@y \n");
print (demo(\@stuff),"\n");
print (scalar(demo(\$thing)),"\n");
print (demo(\%what),"\n");
}

sub demo {
        my ($p) = @_;
        print ("\n\nthis is a ",ref($p)," with ",$#_+1," params\n");

        $silly = 16;

        my ($q,$r,$s) = caller();
        print ("I am called from package $q program file $r line $s\n");
        no warnings;
        my ($q,$r,$s) = caller(1); # (And more fields are available - RTFM)
        use warnings;
        print ("That was called from package $q program file $r line $s\n");

        $stupid = "git";

        if (wantarray) {
                return (2,4,6,8);
        } else {
                return "milkbottle";
        }

}
} # end of package

eggs::yolk();
# eggs::yolk("yellow"); # Commented out. Would give error at prototype

__END__

wizard:course graham$ perl waw
Name "eggs::stupid" used only once: possible typo at waw line 35.

this is a with 2 params
I am called from package eggs program file waw line 13
That was called from package main program file waw line 46
milkbottle

this is a with 1 params
I am called from package eggs program file waw line 15
That was called from package main program file waw line 46
2 4 6 8

this is a ARRAY with 1 params
I am called from package eggs program file waw line 17
That was called from package main program file waw line 46
2468

this is a SCALAR with 1 params
I am called from package eggs program file waw line 18
That was called from package main program file waw line 46
milkbottle

this is a HASH with 1 params
I am called from package eggs program file waw line 19
That was called from package main program file waw line 46
2468
wizard:course graham$

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Other Examples

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