| name | terminal-command-safety |
| description | Safe terminal command patterns — backtick escaping, output capture, and hang prevention |
| tier | core |
| applyTo | ** |
| currency | 2026-04-20T00:00:00.000Z |
Terminal Command Safety
Detailed patterns and examples for safe terminal command execution in AI agent contexts.
Backtick Hazard — Details
Backticks in terminal command arguments break across all shells:
- bash/zsh: backtick = command substitution (
echo "use ls here" executes ls)
- PowerShell: backtick = escape character (
echo "use n here"` inserts newline)
Ref: vscode#295620
Safe Pattern (bash)
cat > /tmp/body.md << 'EOF'
- Added `MyClass` to the module
- Updated `config.py`
EOF
gh pr create --title "My PR" --body-file /tmp/body.md
rm /tmp/body.md
Safe Pattern (PowerShell)
$body = @'
## Changes
- Added `MyClass` to the module
'@
$body | Out-File -Encoding utf8 "$env:TEMP\body.md"
gh pr create --title "My PR" --body-file "$env:TEMP\body.md"
Remove-Item "$env:TEMP\body.md"
Output Capture — Examples
Refs: vscode#308610, vscode#308048, vscode#307173
Redirect to file
npm run build 2>&1 | Out-File -Encoding utf8 "$env:TEMP\build-output.txt"
Get-Content "$env:TEMP\build-output.txt" -Tail 50
Pipe through Out-String
git log --oneline -20 | Out-String
Sentinel pattern
npm test 2>&1; echo "EXIT_CODE:$LASTEXITCODE"
Alt-buffer avoidance
git log not git log | less (set $env:GIT_PAGER="cat")Get-Help not mangh issue view --json not gh issue view (which opens a pager)
Terminal Hanging — Examples
Refs: vscode#308610, vscode#306490
Async mode selection
mode=async for: npm start, dotnet run, docker compose up, long test suites
mode=sync with timeout=30000 for: npm install, git operations, single test files
Pre-answer interactive prompts
npm install --yes
rm -rf (not rm -ri)
az login --use-device-code
git commit --no-edit (merge commits)
Network timeouts
npm install --prefer-offline --no-audit
curl --max-time 30 --connect-timeout 10 $url
