Pourquoi socket_streror ne parvient pas parfois à renvoyer le message d'erreur attendu?

<span><span><span class="hljs-meta"><?php</span></span><span>
</span><span><span class="hljs-comment">// Préface，N&#39;a rien à voir avec le contenu du texte</span></span><span>
</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"Ceci est la partie pré-sortie du programme，Utilisé pour initialiser l&#39;environnement。<br>"</span></span><span>;
</span><span><span class="hljs-variable">$startTime</span></span><span> = </span><span><span class="hljs-title function_ invoke__">microtime</span></span><span>(</span><span><span class="hljs-literal">true</span></span><span>);
</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"Temps de démarrage du programme："</span></span><span> . </span><span><span class="hljs-variable">$startTime</span></span><span> . </span><span><span class="hljs-string">"<br>"</span></span><span>;
</span><span><span class="hljs-meta">?></span></span><span>
<hr>

</span><span><span class="hljs-meta"><?php</span></span><span>
</span><span><span class="hljs-comment">// Démarrer le texte</span></span><span>
</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"<h1>Pourquoi socket_strerror Parfois, le message d&#39;erreur attendu ne peut pas être retourné？</h1>"</span></span><span>;

</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"<p>exister PHP milieu，<code>socket_strerror()