suaveant has asked for the wisdom of the Perl Monks concerning the following question:

I am trying to wrap a sub to get data on how long it ran, etc... kind of like Devel::DProf except not, since this is an FCGI which doesn't lend itself the DProf... so when I do 
return &$ref;

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it works fine but when I do 
my @a;
if(wantarray) {
    @a = &$ref;
} else {
    $a[0] = &$ref;
}
... do something ...
return @a;
#or 
return wantarray ? @a : $a[0];

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Any idea what I am doing wrong, since this second way makes weird things happen, which tell me some data isn't getting returned right...

                - Ant
                - Some of my best work - Fish Dinner

Replies are listed 'Best First'.
Re: Returning data from wrapped sub
by dragonchild (Archbishop) on Aug 30, 2001 at 00:59 UTC
    The actual question is why 
    return wantarry ? @a : $a[0];

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    isn't the same as 
    my @a;
if(wantarray) {
    @a = &$ref;
} else {
    $a[0] = &$ref;
}
... do something ...
return @a;

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    Try doing 
    return (wantarray ? @a : $a[0]);

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    That should work. The issue is how return works with wantarray.

    ------
    We are the carpenters and bricklayers of the Information Age.

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[reply]
[d/l]
[select]
(tye)Re: Returning data from wrapped sub
by tye (Sage) on Aug 30, 2001 at 02:48 UTC
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(jeffa) Re: Returning data from wrapped sub
by jeffa (Bishop) on Aug 30, 2001 at 00:40 UTC
    i am a little confused as to what you are trying to do specifically, but how about this: 
    use strict;
use Data::Dumper;

my $ref = \&bar;

my @arry = foo($ref);
my $scal = foo($ref);

print Dumper @arry;
print Dumper $scal;

sub foo {
   my $ref = shift;
   my @a   = &$ref;
   return wantarray ? @a : $a[0];
}

sub bar { (1..4) }

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    jeffa

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[d/l]
      ahh.... but that calls &$ref in list context no matter what yes? Which could screw things up... say for subs that return an array ref is called scalar and a list if called in list context...

                      - Ant
                      - Some of my best work - Fish Dinner

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        Nope - try this: 
        use strict;
use Data::Dumper;

my $ref = \&bar;
my @arry = foo($ref);
$ref = \&baz;
my $scal = foo($ref);

print Dumper @arry;
print Dumper $scal;

sub foo {
    my $ref = shift;
    my @a = &$ref;
    return wantarray ? @a : $a[0];
}

sub bar { (1..4) }
sub baz { [(1..4)] }

        [download]

        jeffa

[reply]
[d/l]

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