!7

sclass NumberOfMics > DynBigNumber {
  void start {
    thread { actualUpdate(); }
  }
  
  void actualUpdate {
    temp enter();
    S text = apacheCommonsExec_backtick("arecord -l");
    printIndent(text);
    setValue(or(regexpFirstGroup_lastMatch("\\bcard (\\d+):", text), "?"));
  }
}