Function exec

source code/utils/Shell.ts:183–444

(
  command: string,
  abortSignal: AbortSignal,
  shellType: ShellType,
  options?: ExecOptions,
)

 * Creates a new shell process for each command execution
 */
export async function exec(
  command: string,
  abortSignal: AbortSignal,
  shellType: ShellType,
  options?: ExecOptions,
): Promise<ShellCommand> {
  const {
    timeout,
    onProgress,
    preventCwdChanges,
    shouldUseSandbox,
    shouldAutoBackground,
    onStdout,
  } = options ?? {}
  const commandTimeout = timeout || DEFAULT_TIMEOUT

  const provider = await resolveProvider[shellType]()

  const id = Math.floor(Math.random() * 0x10000)
    .toString(16)
    .padStart(4, '0')

  // Sandbox temp directory - use per-user directory name to prevent multi-user permission conflicts
  const sandboxTmpDir = posixJoin(
    process.env.CLAUDE_CODE_TMPDIR || '/tmp',
    getClaudeTempDirName(),
  )

  const { commandString: builtCommand, cwdFilePath } =
    await provider.buildExecCommand(command, {
      id,
      sandboxTmpDir: shouldUseSandbox ? sandboxTmpDir : undefined,
      useSandbox: shouldUseSandbox ?? false,
    })

  let commandString = builtCommand

  let cwd = pwd()

  // Recover if the current working directory no longer exists on disk.
  // This can happen when a command deletes its own CWD (e.g., temp dir cleanup).
  try {
    await realpath(cwd)
  } catch {
    const fallback = getOriginalCwd()
    logForDebugging(
      `Shell CWD "${cwd}" no longer exists, recovering to "${fallback}"`,
    )
    try {
      await realpath(fallback)
      setCwdState(fallback)
      cwd = fallback
    } catch {
      return createFailedCommand(
        `Working directory "${cwd}" no longer exists. Please restart Claude from an existing directory.`,
      )
    }
  }