title: How to capture output of subprocess.call
body: <p>I have made a script that tells me the temperature of my Raspberry Pi 3, but there is a problem with the script.  The result output is the bot saying "Your RPI3 temp is currently 0". What is wrong with my code?</p>
  
  <pre><code>@bot.command(pass_context=True)
  async def vcgencmdmeasure_temp(ctx):
      if ctx.message.author.id == "412372079242117123":
          await bot.say("OK....")
          return_code = subprocess.call("vcgencmd measure_temp", shell=True)
          await bot.say("KK done")
          await bot.say("Your RPI3 temp is currently: {}".format(return_code))
      else:
          await bot.say("Error user lacks perms(only bot owner can run this)")
  </code></pre>
  
  <p>EDIT: i know want to run any command. 
  Current script</p>
  
  <p>@bot.command(pass_context=True)
  async def rpicmd(ctx, *args):</p>
  
  <pre><code>if ctx.message.author.id == "412372079242117123":
      mesg = ''.join(args)
      mesg = str(mesg)
      command_output = subprocess.check_output(mesg, shell=True, universal_newlines=True)
      await bot.say(command_output)
  else:
      await bot.say("No noob")
  </code></pre>
  
  <p>and i get the error:</p>
  
  <pre><code>raise CommandInvokeError(e) from e
  discord.ext.commands.errors.CommandInvokeError: Command raised an 
   exception: CalledProcessError: Command 'vcgencmdmeasure_temp' returned 
    non-zero exit status 12
  </code></pre>