perl - How to use GetOptions to detect trailing strings? -

i absolutely new perl , trying figure out problem perl script parsing script arguments.

i have following perl script called sample-perl.pl:

use strict; use warnings; use 5.010; use getopt::long qw(getoptions);  $source_address; $dest_address;  getoptions('from=s' => \$source_address,            'to=s' => \$dest_address) or die "usage: $0 --from name --to name\n"; if ($source_address) {     $source_address; }  if ($dest_address) {     $dest_address; } 

and if use command (where forgot enter second option):

perl sample-perl.pl --from nyc lon output be: nyc 

how can enforce if there additional string @ end, detected , error displayed instead?

solution:

adding case @ least:

if(@argv){     //throw error } 

after calling getoptions, check remaining command line options in @argv array. assumes unexpected arguments generate error:

use strict; use warnings; use 5.010; use getopt::long qw(getoptions);  $source_address; $dest_address;  getoptions('from=s' => \$source_address,            'to=s' => \$dest_address) or die "usage: $0 --from name --to name\n";  @argv , die "error: unexpected args: @argv";  if ($source_address) {     $source_address; }  if ($dest_address) {     $dest_address; }