Server uptime command to find out how long the system has been running

You would like to find out how long the system has been running. Linux and UNIX comes with various command to find out server uptime command. Under Linux file /proc/uptime has uptime information, /var/run/utmp has information about who is currently logged on. However, information from /proc or utmp file is not directly readable by humans so we use following commands:

Uptime command

$ uptime

17:08:49 up  5:54,  6 users,  load average: 2.03, 1.68, 1.50

uptime command gives a one line display of the following information.

• The current time (17:08:49)
• How long the system has been running (up 5:54)
• How many users are currently logged on (6 users)
• The system load averages for the past 1, 5, and 15 minutes (2.03, 1.68, 1.5)

This is the same information contained in the header line displayed by w and top command:

$ w
$ top

Note that w displays who is logged on and what they are doing while top command provides a dynamic real-time view of a running Linux/UNIX/BSD system.