apply code suggestions from code review

Author: michalsn

composer.json

@@ -46,7 +46,9 @@
         "ext-memcached": "If you use Cache class MemcachedHandler with Memcached",
         "ext-mysqli": "If you use MySQL",
         "ext-oci8": "If you use Oracle Database",
+        "ext-pcntl": "If you use Signals",
         "ext-pgsql": "If you use PostgreSQL",
+        "ext-posix": "If you use Signals",
         "ext-readline": "Improves CLI::input() usability",
         "ext-redis": "If you use Cache class RedisHandler",
         "ext-simplexml": "If you format XML",

system/CLI/SignalTrait.php

@@ -123,6 +123,7 @@ protected function registerSignals(
             if (pcntl_signal($signal, [$this, 'handleSignal'])) {
                 $this->registeredSignals[] = $signal;
             } else {
+                $signal = $this->getSignalName($signal);
                 CLI::write("Failed to register handler for signal: {$signal}", 'red');
             }
         }