// To begin log-life, simply call with the target log file.
    var LogLife = require('log-life');
    LogLife('/var/log/mylog');

    // Available for specify multiple files
    LogLife('/var/log/mylog1', '/var/log/mylog2');

    * span  
      ... executing maintenance interval time.  
      (millisecond. w[eek], h[ours] also available.)
    * cap
      ... executing maintenance file-size  
      (bytes. k[bytes], M[bytes], G[bytes] also available.)
    * stock 
      ... preserve num of log archive

    // setting a maintenance targets with options
     LogLife('/var/log/mylog1', {
     
       // maintenance per day
       span: 24 * 60 * 60 * 1000, 
       
       // max 3 archives
       stock: 3
       
     })

    // start log maintenance
    // *automatically* starts when LogLife() calls.
    LogLife.start(<Number>checking_interval_millisec || 1000)

    // stop log maintenance
    LogLife.stop()

    // getting a life for a file
    LogLife.get(<String>filepath)

    // stop log maintenance
    LogLife.stop()

    // logfile filepath 
    life.filepath
    // logfile mainteanace span
    life.span
    // logfile stock archives num
    life.stock

    // logfile size 
    var life = LogLife.get(filepath);
    life.size().then(function(size) { ... })

    // logfile related archive list 
    var life = LogLife.get(filepath);
    life.list().then(function(list) { ... })