How to invoke the method dynamically using universal::can

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

Hi, I need to invoke the method based on the user input. I have the following script and it works.

Can you please explain how does this line work? $func->(%opts);

This line $func->(%opts) do not have any return statement; But it returns the value properly

Thanks

Code:

#!/usr/local/bin/perl

use strict;
use Getopt::Long qw(:config gnu_getopt);

###########################################
# Parses the commad line arguments
# Example: callfunction.pl -action getInfo
###########################################
sub parse_args {
my %opts;
GetOptions(\%opts,
"action=s",
);
return %opts;
}

my %opts = parse_args();
my $action = $opts{action};

my $output = call_function($action, %opts);


=head call_function ($function_name, %params)
This method invokes the appropriate subroutine based on the funcname p
+assed
=cut
sub call_function {
my $funcname = shift;
my %opts = @_;
my $package = 'main';
if ( my $func = UNIVERSAL::can($package, $funcname) ) {
$func->(%opts);
}
else {
die "no such function $package\::$funcname\n";
}
}

sub getInfo {
my $msg = shift;
return $msg;
}
[download]

Comment on How to invoke the method dynamically using universal::can Download Code

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Re: How to invoke the method dynamically using universal::can by ikegami (Patriarch) on Sep 23, 2010 at 15:39 UTC
Note that `can` makes no sense for function calls. It checks inheritance. For functions, you should use something like the following: `sub call_function { my $funcname = shift; my $package = caller(); my $qfuncname = "${package}::$funcname"; no strict 'refs'; exists(&$qfuncname) or die("no such function $qfuncname\n"); return &{$qfuncname}(@_); } sub f { print "f\n"; } call_function('f'); call_function('g');` [download] `f no such function main::g` [download]	[reply] [d/l] [select]
Re: How to invoke the method dynamically using universal::can by Corion (Patriarch) on Sep 23, 2010 at 15:18 UTC
See return: (In the absence of an explicit return, a subroutine, eval, or do FILE automatically returns the value of the last expression evaluated.)	[reply]