text: # Copyright (c) 2021 Red Hat, Inc.
  #
  # All Rights Reserved.
  #
  #    Licensed under the Apache License, Version 2.0 (the "License"); you may
  #    not use this file except in compliance with the License. You may obtain
  #    a copy of the License at
  #
  #         http://www.apache.org/licenses/LICENSE-2.0
  #
  #    Unless required by applicable law or agreed to in writing, software
  #    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
  #    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
  #    License for the specific language governing permissions and limitations
  #    under the License.
  from __future__ import absolute_import
  
  import functools
  import os
  
  from oslo_log import log
  
  import tobiko
  from tobiko.shell.sh import _command
  from tobiko.shell.sh import _exception
  from tobiko.shell.sh import _execute
  from tobiko.shell import ssh
  
  
  LOG = log.getLogger(__name__)
  
  
  class GetCommandLineError(tobiko.TobikoException):
      message = "Unable to get process command line: {error}"
  
  
  class GetCommandLineMismatch(GetCommandLineError):
      message = ("Command line of process ({pid}) doesn't match its command "
                 "({command}): {command_line}")
  
  
  @functools.lru_cache(typed=True)
  def get_command_line(pid: int,
                       ssh_client: ssh.SSHClientType = None,
                       command: str = None,
                       _cache_id: int = None) \
          -> _command.ShellCommand:
      try:
          output = _execute.execute(f'cat /proc/{pid}/cmdline',
                                    ssh_client=ssh_client).stdout
      except _exception.ShellCommandFailed as ex:
          raise GetCommandLineError(error=ex.stderr) from ex
  
      command_line = _command.ShellCommand(output.strip().split('\0')[:-1])
      if not command_line:
          raise GetCommandLineError(error="command line is empty")
  
      if command is not None and os.path.basename(command_line[0]) != command:
          raise GetCommandLineMismatch(pid=pid, command=command,
                                       command_line=command_line)
      return command_line
  