生產環境：CentOS
[sky9890@sky9890 ~]$ cat /etc/redhat-release
CentOS release 6.10 (Final)
[sky9890@sky9890 ~]$ uptime -V
procps version 3.2.8
[sky9890@sky9890 ~]$ uptime
19:54:34 up 18 days, 1:49, 2 users, load average: 0.19, 0.17, 0.11
虛擬機環境:RHEL7.0
[sky@sky ~]$ cat /etc/redhat-release
Red Hat Enterprise Linux Server release 7.0 (Maipo)
[sky@sky ~]$ uptime -h
Usage:
uptime [options]
# Tell how long the system has been running.
Options:
-p, --pretty show uptime in pretty format
-h, --help display this help and exit
-s, --since system up since
-V, --version output version information and exit
[sky@sky ~]$ uptime -V
uptime from procps-ng 3.3.9
[sky@sky ~]$ uptime -s
2018-12-01 19:55:52
[sky@sky ~]$ uptime -p
up 5 minutes
虛擬機環境:Ubuntu 16.10
實戰技巧：
1.uptime procps version 3.2.8以後版本才增加"-s","-p","-h"參數；
2.說明RHEL、CentOS、Ubuntu等系統操作uptime命令時帶來區別的原因是uptime版本所致。
3.W命令與uptime有同樣功能，如下
[root@sky9890 src]# w
21:12:30 up 18 days, 3:07, 1 user, load average: 0.28, 0.22, 0.19
USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT
sky9890 pts/0 117.44.69.112 20:42 0.00s 0.06s 0.03s sshd: sky9890 [priv]
[root@sky9890 src]# uptime
21:14:44 up 18 days, 3:09, 1 user, load average: 0.10, 0.18, 0.17