WordPress 文章版權聲明總整理：文末自動加版權簽名、複製內容自動附上出處

add_filter( 'the_content', 'ahwei_post_copyright', 20 );
function ahwei_post_copyright( $content ) {
    // 只在單篇文章的本文加,其他地方不動
    if ( ! is_singular( 'post' ) || ! in_the_loop() || ! is_main_query() || get_the_ID() !== get_queried_object_id() ) {
        return $content;
    }

    $notice = sprintf(
        '<div class="post-copyright"><p>本文為「%1$s」原創內容，歡迎分享，轉載請註明出處並附上原文連結：</p><p><a href="%2$s">%3$s</a></p></div>',
        esc_html( get_bloginfo( 'name' ) ),
        esc_url( get_permalink() ),
        esc_html( get_the_title() )
    );

    return $content . $notice;
}

$notice = sprintf(
    '<div class="post-copyright"><p>✎ 作者：%1$s</p><p>本文連結：<a href="%2$s">%2$s</a></p><p>轉載請註明出處，謝謝！</p></div>',
    esc_html( get_the_author() ),
    esc_url( get_permalink() )
);

.post-copyright {
  margin: 2.5em 0 1em;
  padding: 1em 1.25em;
  border: 1px solid #cfe0f5;
  border-left: 4px solid #4094ef;
  border-radius: 6px;
  background: #f5f9ff;
  font-size: 0.95em;
  line-height: 1.8;
}

.post-copyright p {
  margin: 0;
}

.post-copyright a {
  color: #c2185b;
  word-break: break-all; /* 網址太長時自動換行,手機才不會破版 */
}

add_filter( 'the_content_feed', function ( $content ) {
    return $content . sprintf(
        '<p>本文出自〈<a href="%1$s">%2$s</a>〉，原文刊登於 %3$s。</p>',
        esc_url( get_permalink() ),
        esc_html( get_the_title() ),
        esc_html( get_bloginfo( 'name' ) )
    );
} );

add_action( 'wp_footer', 'ahwei_copy_with_source' );
function ahwei_copy_with_source() {
    if ( ! is_singular( 'post' ) ) {
        return;
    }
    ?>
    <script>
    document.addEventListener('copy', function (event) {
        var selection = window.getSelection();
        if (!event.clipboardData || !selection || selection.rangeCount === 0) return;

        var text = selection.toString();
        if (text.trim().length < 50) return; // 太短的不附加

        // 在輸入框、程式碼區塊裡複製,保持原樣
        var active = document.activeElement;
        if (active && active.matches('input, textarea, [contenteditable="true"]')) return;
        var node = selection.anchorNode;
        var el = node && (node.nodeType === 1 ? node : node.parentElement);
        if (el && el.closest('pre, code')) return;

        var url = <?php echo wp_json_encode( get_permalink( get_queried_object_id() ) ); ?>;
        var title = document.title;

        // 純文字版本
        event.clipboardData.setData('text/plain', text + '\n\n出處：' + title + '\n' + url);

        // 保留格式的版本(貼到 Word、Email 時使用)
        var box = document.createElement('div');
        box.appendChild(selection.getRangeAt(0).cloneContents());
        var p = document.createElement('p');
        var a = document.createElement('a');
        a.href = url;
        a.textContent = title;
        p.append('出處：', a);
        box.appendChild(p);
        event.clipboardData.setData('text/html', box.innerHTML);

        event.preventDefault();
    });
    </script>
    <?php
}