How to use GetOptions to detect trailing strings? - perl

Question

I am absolutely new to Perl and I am trying to figure out a problem with Perl script parsing script arguments.
I have the following Perl script called sample-perl.pl:
use strict;
use warnings;
use 5.010;
use Getopt::Long qw(GetOptions);
my $source_address;
my $dest_address;
GetOptions('from=s' => \$source_address,
'to=s' => \$dest_address) or die "Usage: $0 --from NAME --to NAME\n";
if ($source_address) {
say $source_address;
}
if ($dest_address) {
say $dest_address;
}
And if I use a command like (where I forgot to enter the second option):
perl sample-perl.pl --from nyc lon
Output will be: nyc
How can I enforce that if there is an additional string at the end, it is detected and an error is displayed instead?
Solution:
adding this will help my case at least:
if(#ARGV){
//throw error
}

Answer 1

After calling GetOptions, check for any remaining command line options in the #ARGV array. This assumes that all unexpected arguments will generate an error:
use strict;
use warnings;
use 5.010;
use Getopt::Long qw(GetOptions);
my $source_address;
my $dest_address;
GetOptions('from=s' => \$source_address,
'to=s' => \$dest_address) or die "Usage: $0 --from NAME --to NAME\n";
#ARGV and die "Error: unexpected args: #ARGV";
if ($source_address) {
say $source_address;
}
if ($dest_address) {
say $dest_address;
}

Answer 2

I was busy answered and I see it is now answered, just some additional info.
use strict;
use warnings;
use 5.010;
use Getopt::Long qw(GetOptions);
my $source_address;
my $dest_address;
GetOptions('from=s' => \$source_address,
'to=s' => \$dest_address) or die "Usage: $0 --from NAME --to NAME\n";
#ARGV and die "To many arguments after --from or --to : #ARGV ";
if ($source_address) {
say $source_address;
} else {
say "Error: No Source specified"; #Check to see if --from is actually specified, else print error.
}
if ($dest_address) {
say $dest_address;
} else {
say "Error: No destination specified"; #Check to see if --to is actually specified, else print error.
}
so in short