/*
    * Copyright 2020-2022 The OSHI Project Contributors
    * SPDX-License-Identifier: MIT
    */
   package oshi.driver.linux.proc;
   
   import oshi.annotation.concurrent.ThreadSafe;
   import oshi.util.FileUtil;
   import oshi.util.ParseUtil;
  import oshi.util.platform.linux.ProcPath;
  
  /**
   * Utility to read system uptime from {@code /proc/uptime}
   */
  @ThreadSafe
  public final class UpTime {
  
      private UpTime() {
      }
  
      /**
       * Parses the first value in {@code /proc/uptime} for seconds since boot
       *
       * @return Seconds since boot
       */
      public static double getSystemUptimeSeconds() {
          String uptime = FileUtil.getStringFromFile(ProcPath.UPTIME);
          int spaceIndex = uptime.indexOf(' ');
          if (spaceIndex < 0) {
              // No space, error
              return 0d;
          }
          return ParseUtil.parseDoubleOrDefault(uptime.substring(0, spaceIndex), 0d);
      }
  }