text: ##############################################################################
  # Copyright (c) 2016 Juan Qiu
  # juan_ qiu@tongji.edu.cn
  # All rights reserved. This program and the accompanying materials
  # are made available under the terms of the Apache License, Version 2.0
  # which accompanies this distribution, and is available at
  # http://www.apache.org/licenses/LICENSE-2.0
  ##############################################################################
  import logging
  import subprocess
  import traceback
  
  LOG = logging.getLogger(__name__)
  
  
  def buildshellparams(param, remote=True):
      result = '/bin/bash -s' if remote else ''
      result += "".join(" {%d}" % i for i in range(len(param)))
      return result
  
  
  def execute_shell_command(command):
      """execute shell script with error handling"""
      exitcode = 0
      output = []
      try:
          LOG.debug("the command is: %s", command)
          output = subprocess.check_output(command, shell=True)
      except Exception:
          exitcode = -1
          output = traceback.format_exc()
          LOG.error("exec command '%s' error:\n ", command)
          LOG.error(traceback.format_exc())
      return exitcode, output
  
  PREFIX = '$'
  
  
  def build_shell_command(param_config, remote=True, intermediate_variables=None):
      param_template = '/bin/bash -s' if remote else ''
      if intermediate_variables:
          for key, val in param_config.items():
              if str(val).startswith(PREFIX):
                  try:
                      param_config[key] = intermediate_variables[val]
                  except KeyError:
                      pass
      result = param_template + "".join(" {}".format(v) for v in param_config.values())
      LOG.debug("THE RESULT OF build_shell_command IS: %s", result)
      return result
  
  
  def read_stdout_item(stdout, key):
      if key == "all":
          return stdout
      for item in stdout.splitlines():
          if key in item:
              attributes = item.split("|")
              if attributes[1].lstrip().startswith(key):
                  return attributes[2].strip()
      return None
  