List of signals on Linux: man -S 7 signal

To send a signal use kill SIG, LIST (process IDs)

For example: kill 9, $pid;

examples/advanced/signal.pl
use strict;
use warnings;

my ($sig, @process) = @ARGV;

die "Usage: $0 SIGNAL PROCESS-ID\n" if not @process;
kill $sig, @process;

%SIG

$SIG{INT}  = sub { print "INT received\n";};         # kill -2  or Ctrl-C
$SIG{TERM} = sub { print "TERM received\n"; exit;};  # kill -15
$SIG{TSTP} = sub { print "TSTP received\n";};        # kill -20 or Ctrl-Z

$SIG{KILL} = sub { print "KILL received\n"; exit;};  # kill -9  cannot catch it


$SIG{$name} = 'IGNORE';             # to ignore it
$SIG{$name} = 'DEFAULT';            # to reset to the default behavior