Not sure if it's a Solaris specific thing, but I used this on Linux with perl 5.8.8 and it works fine:

use sigtrap qw(handler sig_handler INT TERM QUIT PIPE);
use Switch;

sub sig_handler {
    my($sig) = shift;
    print "Caught signal $sig\n";

    switch($sig) {
        case ["INT","TERM","QUIT"] {
             print "Exiting";
             exit(0);
        }
        case "PIPE" {
            print "Continuing\n";
        }

    }
}
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