Select Code to Download

use strict;
use warnings;
...
    print "Option -$_[0] is value=$_[1]\n";
    $args{$_[0]} = $_[1];
}

$ ./test.pl -t asdf -c qwer
Warning: arg -t without preceding -c: arg -t ignored at ./test.pl line
+ 13.
Option -c is value=qwer
Error: argument processing did not complete successfully at ./test.pl 
+line 18.

use strict;
use warnings;
...
    print "Option -$_[0] is value=$_[1]\n";
    $args{$_[0]} = $_[1];
}

$ ./test.pl -t asdf -c qwer
Error: arg -t without preceding -c: processing terminated at ./test.pl
+ line 13.

use strict;
use warnings;
...
    print "Option -$_[0] is value=$_[1]\n";
    $args{$_[0]} = $_[1];
}

$ ./test.pl foo -t bar -c baz
Frobnicating foo
Error: arg -t without preceding -c: processing terminated at ./test.pl
+ line 13.