title: Check if a process is running using Python on Linux
body: <p>I am trying to find if the process is running based on process id. The code is as follows based on one of the post on the forum. I cannot consider process name as there are more than one process running with the same name. </p>
  
  <pre><code>def findProcess( processId ):
      ps= subprocess.Popen("ps -ef | grep "+processId, shell=True, stdout=subprocess.PIPE)
      output = ps.stdout.read()
      ps.stdout.close()
      ps.wait()
      return output
  def isProcessRunning( processId):
      output = findProcess( processId )
      if re.search(processId, output) is None:
          return true
      else:
          return False
  </code></pre>
  
  <p>Output :</p>
  
  <pre><code>1111 72312 72311   0   0:00.00 ttys000    0:00.00 /bin/sh -c ps -ef | grep 71676
  1111 72314 72312   0   0:00.00 ttys000    0:00.00 grep 71676
  </code></pre>
  
  <p>It always return true as it can find the process id in the output string. </p>
  
  <p>Any suggestions? Thanks for any help.</p>