Re: How do I call a sub using a variable as its name, objectively

Choroba showed you how to do it, however allowing calls to arbitrary functions can be a bit of a security hole. To get around that I usually decorate the sub name after the user has provided it:

use strict;
use warnings;

package My;

sub new {
    my ($class) = @_;
    return bless {}, $class;
    }

sub ext_show {
    my ($self, $name) = @_;
    print "Hello $name!\n";
    return 1;
    }

package main;

my $A = 'My'->new();
my $method = 'ext_' . shift;

$A->$method(@ARGV);
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Prints:

Hello Bob!
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when given the command line parameters show Bob. Because 'ext_' is added a prefix to the actual name it's not possible for the user to call an unintended sub.

Optimising for fewest key strokes only makes sense transmitting to Pluto or beyond

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Re^2: How do I call a sub using a variable as its name, objectively by ysth (Canon) on Oct 28, 2024 at 23:21 UTC
Or use a whitelist: `my $A = My::->new(); my $method = $method_list{$ARGV[0]} or die "Invalid method $ARGV[0]."; $A->$method(@ARGV[1..$#ARGV]);` [download] -- A math joke: r = \| \|csc(θ)\|+\|sec(θ)\| \|-\| \|csc(θ)\|-\|sec(θ)\| \|	[reply] [d/l]
Re^3: How do I call a sub using a variable as its name, objectively by GrandFather (Saint) on Oct 29, 2024 at 05:23 UTC
I have done that in the past, but the list, the implementation and the documentation all have to be updated. Using the prefix trick avoids the need to update the list. I admit, a fairly minor point, but it does reduce scope for error. Optimising for fewest key strokes only makes sense transmitting to Pluto or beyond	[reply]