Unix Manual Server

Instructions

Implementation Reference

• unix_manual_server.py:311-359 (handler)

  The @mcp.tool()-decorated function implementing the 'check_command_exists' MCP tool handler. It checks if the specified command exists on the system by finding its path using get_command_path, validates the command name, and attempts to retrieve version information using --version, -V, or version subcommands.

  @mcp.tool()
  def check_command_exists(command: str) -> str:
      """
      Check if a command exists on the system.
  
      Args:
          command: The command to check
  
      Returns:
          Information about whether the command exists
      """
      logger.info(f"Checking if command exists: '{command}'")
      command_name = command.strip().split()[0]
      logger.debug(f"Extracted command name: {command_name}")
  
      if not re.match(r'^[a-zA-Z0-9_\.-]+$', command_name):
          logger.warning(f"Invalid command name: '{command_name}'")
          return f"Invalid command name: '{command_name}'"
  
      command_path = get_command_path(command_name)
      if command_path:
          logger.info(f"Command '{command_name}' exists at {command_path}")
  
          # Try --version
          logger.debug(f"Trying --version for {command_name}")
          version_result = safe_execute([command_path, "--version"], timeout=5)
          if version_result and version_result.returncode < 2 and version_result.stdout.strip():
              logger.debug(f"Got version info using --version for {command_name}")
              return f"Command '{command_name}' exists at {command_path}.\nVersion information: {version_result.stdout.strip()}"
  
          # Try -V (some commands use this for version)
          logger.debug(f"Trying -V for {command_name}")
          version_result = safe_execute([command_path, "-V"], timeout=5)
          if version_result and version_result.returncode < 2 and version_result.stdout.strip():
              logger.debug(f"Got version info using -V for {command_name}")
              return f"Command '{command_name}' exists at {command_path}.\nVersion information: {version_result.stdout.strip()}"
  
          # Try version
          logger.debug(f"Trying version subcommand for {command_name}")
          version_result = safe_execute([command_path, "version"], timeout=5)
          if version_result and version_result.returncode < 2 and version_result.stdout.strip():
              logger.debug(f"Got version info using version subcommand for {command_name}")
              return f"Command '{command_name}' exists at {command_path}.\nVersion information: {version_result.stdout.strip()}"
  
          return f"Command '{command_name}' exists on this system at {command_path}."
      else:
          logger.warning(f"Command '{command_name}' does not exist or is not in the PATH")
          return f"Command '{command_name}' does not exist or is not in the PATH."