Cpp-Input-Guard

An Obsidian plugin that keeps Markdown syntax out of the way of C++ notes. It escapes trigger characters as you type or paste, and can repair notes you have already written — while leaving code blocks, inline code and genuine link syntax untouched.

中文版见本文件下半部分（Chinese version below）。

The problem

Markdown gives a second meaning to characters C++ uses constantly.

You write	Markdown sees	Result
greater<int>	an unclosed HTML tag	everything after it is swallowed into the element
arr[5], [note]	the start of a link	the brackets vanish, or become a link to nowhere
#include <iostream>	a tag	#include is collected into the tag pane
a == b	a highlight span	everything between the two == is highlighted
a*b*c, int** p	emphasis	the asterisks turn into italic / bold
"C:\\path"	an escape sequence	the backslash silently eats the next character

Installation

1. Download main.js, manifest.json and versions.json from the latest release.
2. Put them in <vault>/.obsidian/plugins/cpp-input-guard/.
3. Settings → Community plugins → Refresh → enable Cpp-Input-Guard.

Or add Yaki-Blake/Cpp-Input-Guard as a beta plugin via BRAT.

Requires Obsidian 1.4.0+. Plain JavaScript — main.js is the finished artifact — no build step, desktop and mobile.

Escaping rules

You type	Editor writes	Notes
<	\<	a < b, x <= y, <3 are left alone
[	\[	keeps [text](url), [[wikilink]], [^footnote]; escapes subscripts such as arr[5]
*	\*	a line-leading * is restored, so bullet lists still work
_	\_	only at a word boundary; my_var_name is untouched
\	\\	the backslash becomes literal instead of an escape character
==	\==	=== still highlights, so deliberate highlighting works
#include …	\#include …	14 directives only; # Heading and #tag are untouched

Nothing inside fenced code blocks (``` / ~~~) or inline code is touched, and pasted text goes through the same rules.

The 14 directives: include import define undef pragma line error warning ifdef ifndef endif elif else if

Commands

Open the command palette (Ctrl/Cmd + P) and search for repair:

Command	What it does
Toggle: bracket input protection	master switch for interception
Repair current note	escapes the note you are editing
Repair current file (works in Reading view)	works in any view mode
Repair entire vault	bulk repair, with a confirmation dialog
Escape Markdown trigger characters in selection	selection only
Restore current file from the most recent backup	rolls back to the newest backup
Restore a note from backup (open settings)	jumps to the restore panel

Repair is idempotent (\< never gains a second backslash), skips code, and leaves a < b alone. A <name>.md.bak-<timestamp> copy is written before every repair.

Settings

Input protection — master switch, <, [, preserve links, skip fenced blocks, skip inline code, escape on paste. All on by default.

Markdown suppression — directives are not tags, disable italics (keep list bullets), disable underscore italics, highlight only on ===, backslash is literal. All on by default.

Repair — back up before repair (on), repair on open (off, because it writes to disk).

Backups & restore — pick a note → pick a version → Restore / Refresh.

Other — notice on load, notice on toggle (both on).

Limitations

• Edit mode only (Source mode and Live Preview); existing notes need a repair run.
• Escaping rewrites the note source — one extra \ per character. The rendered result is unchanged, but the raw text is less readable.
• With Backslash is literal on, a manually typed \< no longer escapes — write the backslash twice, or turn the setting off.
• YAML frontmatter is not skipped: inline tags: [C++, STL] gets escaped and breaks the property. Keep frontmatter tags in block style.
• Vault-wide repair scans every Markdown file, including any backup folder you keep inside the vault.
• Writing raw HTML such as <div style="...">? Turn the protection off first.

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Cpp-Input-Guard（C++ 输入保护）

Obsidian 插件：让 Markdown 语法不再干扰 C++ 笔记。输入与粘贴时自动转义触发符号，也能一键修复已写好的旧笔记——同时放过围栏代码块、行内代码和正常的链接语法。

解决的问题

Markdown 给很多 C++ 天天在用的符号赋予了第二重含义。

你写的	Markdown 看到的	后果
greater<int>	未闭合的 HTML 标签	后续同级内容全被吞进该元素
arr[5]、[note]	链接的起点	方括号消失，或变成指向空处的链接
#include <iostream>	标签	#include 被收进标签面板
a == b	高亮定界符	两处 == 之间的内容整体变高亮
a*b*c、int** p	强调语法	星号变成斜体 / 粗体
"C:\\path"	转义序列	反斜杠悄悄吞掉后一个字符

安装

1. 从 最新 Release 下载 main.js、manifest.json、versions.json。
2. 放入 <库>/.obsidian/plugins/cpp-input-guard/。
3. 设置 → 第三方插件 → 刷新 → 启用 Cpp-Input-Guard。

也可用 BRAT 添加 Yaki-Blake/Cpp-Input-Guard 作为 beta 插件。

需要 Obsidian 1.4.0+。纯 JavaScript——main.js 即成品——无需构建，桌面端与移动端均可用。

转义规则

你输入	编辑器写入	说明
<	\<	a < b、x <= y、<3 一律放行
[	\[	保留 [文字](地址)、[[双链]]、[^脚注]；转义 arr[5] 这类下标
*	\*	行首「* + 空格」会还原，列表圆点仍可用
_	\_	仅词边界；my_var_name 不动
\	\\	反斜杠按字面显示，不再吞字符
==	\==	=== 仍触发高亮，想高亮时照常用
#include 等	\#include	仅 14 个预处理指令词；# 标题、#tag 不受影响

围栏代码块（``` / ~~~）与行内代码内一律不处理；粘贴进正文的内容走同一套规则。

14 个指令词： include import define undef pragma line error warning ifdef ifndef endif elif else if

命令

命令面板（Ctrl/Cmd + P）搜 repair：

命令	作用
切换：括号输入保护	拦截总开关
修复当前笔记	转义正在编辑的笔记
修复当前文件（阅读模式也可用）	任何视图模式都能用
修复整个库	批量修复，带确认弹窗
转义选区中的 Markdown 触发符号	只处理选中文字
从最近备份还原当前文件	回滚到最新备份
选择笔记还原（打开设置）	跳到还原面板

修复是幂等的（\< 不会变成 \\<），跳过代码块，a < b 不受影响。每次修复写盘前，先生成 <原名>.md.bak-时间戳 副本。

设置

输入保护 —— 总开关、<、[、保留链接语法、跳过围栏代码块、跳过行内代码、粘贴时转义。默认全开。

Markdown 抑制 —— 指令词不当标签、禁用斜体（保留列表圆点）、禁用下划线斜体、仅 === 高亮、反斜杠字面化。默认全开。

修复 —— 修复前备份（开）、打开笔记时自动修复（关，因为会写盘）。

备份与还原 —— 选笔记 → 选版本 → 还原 / 刷新。

其他 —— 加载时提示、命令执行后提示（均开）。

限制

• 只作用于编辑模式（源码模式与实时预览）；老内容需跑一次修复。
• 转义会改写笔记源码——每个字符多一个 \。渲染结果不变，但原文可读性下降。
• 「反斜杠字面化」开启时，手动打的 \< 会失效——写两个反斜杠，或临时关掉该设置。
• YAML frontmatter 不跳过：行内写法 tags: [C++, STL] 会被转义导致属性损坏，请用块状写法。
• 整库修复会扫描库里每一个 Markdown 文件，包括你放在库内的备份目录。
• 若你要特意写裸 HTML（如 <div style="...">），先用切换命令关掉保护。

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License / 许可

Mozilla Public License 2.0

Changelog / 更新日志

• 1.9.0 — renamed everything to Cpp-Input-Guard: the plugin ID is now cpp-input-guard, and the display name and the GitHub repository are Cpp-Input-Guard.
• 1.8.2 — renamed the plugin to cpp-input-protection so the display name matches the plugin ID and the repository; the load notice and the listing text follow.
• 1.8.1 — plugin description rewritten in English to match the English-first README. No functional change.
• 1.8.0 — directive list grew from 3 words to 14; a directive now matches after any whitespace, not only at a line start.
• 1.7.0 — added the Backups & restore section: pick a note and a version, restore without opening the note.
• 1.6.0 — added paste interception and the Restore current file from the most recent backup command.
• 1.5.0 — extended repair to #, ==, * and _, plus automatic backup before every repair write.
• 1.4.0 — Markdown syntax suppression: directives no longer become tags, == no longer highlights, italics disabled while bullets survive, backslash made literal.
• 1.3.0 — added square-bracket protection; renamed from Angle Bracket Shield to C++ Input Protection.
• 1.0.0–1.2.2 — input interception, code awareness, selection escaping, repair commands, release workflow.