code: def has(cmd):
      
      helps = ["--help", "-h", "--version"]
      if "nt" == os.name:
          helps.insert(0, "/?")
      fakecmd = "fakecmd"
      cmderr = strerr(fakecmd).replace(fakecmd, cmd)
      for h in helps:
          hcmd = "%s %s" % (cmd, h)
          if 0 == silent(hcmd):
              return True
          if len(listout(hcmd)) > 0:
              return True
          if strerr(hcmd) != cmderr:
              return True
      return False
docs: Returns true if the give shell command is available.
  
      **Examples**:
      ::
          auxly.shell.has("ls")  # True