Function executeShellCommandsInPrompt

src/utils/promptShellExecution.ts:69–143

(
  text: string,
  context: ToolUseContext,
  slashCommandName: string,
  shell?: FrontmatterShell,
)

 *   See docs/design/ps-shell-selection.md §5.3.
 */
export async function executeShellCommandsInPrompt(
  text: string,
  context: ToolUseContext,
  slashCommandName: string,
  shell?: FrontmatterShell,
): Promise<string> {
  let result = text

  // Resolve the tool once. `shell === undefined` and `shell === 'bash'` both
  // hit BashTool. PowerShell only when the runtime gate allows — a skill
  // author's frontmatter choice doesn't override the user's opt-in/out.
  const shellTool: PromptShellTool =
    shell === 'powershell' && isPowerShellToolEnabled()
      ? getPowerShellTool()
      : BashTool

  // INLINE_PATTERN's lookbehind is ~100x slower than BLOCK_PATTERN on large
  // skill content (265µs vs 2µs @ 17KB). 93% of skills have no !` at all,
  // so gate the expensive scan on a cheap substring check. BLOCK_PATTERN
  // (```!) doesn't require !` in the text, so it's always scanned.
  const blockMatches = text.matchAll(BLOCK_PATTERN)
  const inlineMatches = text.includes('!`') ? text.matchAll(INLINE_PATTERN) : []

  await Promise.all(
    [...blockMatches, ...inlineMatches].map(async match => {
      const command = match[1]?.trim()
      if (command) {
        try {
          // Check permissions before executing
          const permissionResult = await hasPermissionsToUseTool(
            shellTool,
            { command },
            context,
            createAssistantMessage({ content: [] }),
            '',
          )

          if (permissionResult.behavior !== 'allow') {
            logForDebugging(
              `Shell command permission check failed for command in ${slashCommandName}: ${command}. Error: ${permissionResult.message}`,
            )
            throw new MalformedCommandError(
              `Shell command permission check failed for pattern "${match[0]}": ${permissionResult.message || 'Permission denied'}`,
            )
          }

          const { data } = await shellTool.call({ command }, context)
          // Reuse the same persistence flow as regular Bash tool calls
          const toolResultBlock = await processToolResultBlock(
            shellTool,
            data,
            randomUUID(),
          )
          // Extract the string content from the block
          const output =
            typeof toolResultBlock.content === 'string'
              ? toolResultBlock.content
              : formatBashOutput(data.stdout, data.stderr)