shell-tilde-paths

A shell-command rule for handling paths that begin with `~`, the shortcut for a user's home directory, when commands run over SSH.

In plain words
What is it for?
Use it when code builds SSH commands from user- or agent-supplied paths, especially paths such as `~/pentest-workspace`.
Why use it?
It prevents commands from treating `~` inside quotes as literal text, which can make valid file paths fail. It also keeps paths containing spaces from being split incorrectly.

Cursor rule for Cursor

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add rules/bugbasesecurity/pentest-copilot/shell-tilde-paths
Clone the repo
git clone --depth 1 https://github.com/bugbasesecurity/pentest-copilot

Made for: Cursor.

Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 258 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00000 $0.00258
Opus 5 $0.00000 $0.00129
Sonnet 5 $0.00000 $0.00052
Haiku 4.5 $0.00000 $0.00026

Measured 2d ago against content hash 44e04dbeb0a4, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

shell-tilde-paths scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.cursor/rules/shell-tilde-paths.mdc · 29 lines

What it actually says

Shell Path Handling: ~ Does Not Expand in Quotes

WORKSPACE_DIR is ~/pentest-workspace. When constructing shell commands that reference file paths:

  • ~ is not expanded by bash inside double quotes: stat "~/foo" fails (looks for literal ~ directory)
  • $HOME is expanded inside double quotes: stat "$HOME/foo" works correctly

Always replace a leading ~ with $HOME before interpolating paths into quoted shell commands:

// ✅ GOOD
const resolved = rawPath.replace(/^~(?=\/|$)/, "$HOME");
await ctx.runCommand(`stat -c %s "${resolved}"`);

// ❌ BAD — ~ won't expand inside double quotes
await ctx.runCommand(`stat -c %s "${rawPath}"`);

// ❌ BAD — unquoted path breaks on spaces
await ctx.runCommand(`stat -c %s ${rawPath}`);

This applies to any tool handler that takes a user/agent-supplied file path and passes it to ctx.runCommand.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 29 lines · 0 tokens per session scan A 44e04dbeb0a4

Subscribe to this mod's changes

shell-tilde-paths is a cursor rule published in the GitHub repository bugbasesecurity/pentest-copilot (1,340 stars, last pushed 18d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 258 tokens. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.