Some Basic Linux System Commands
Display Linux System Information
[root@web-server ~]# uname -a
Linux web-server.novalocal 3.10.0-229.4.2.el7.x86_64 #1 SMP Fri Apr 24 15:26:38 EDT 2015 x86_64 x86_64 x86_64 GNU/Linux
Display Kernel Release Information
[root@web-server ~]# uname -r
3.10.0-229.4.2.el7.x86_64
Shows how long system has been running plus system load
[root@web-server ~]# uptime
09:36:13 up 17 days, 15:25, 1 user, load average: 0.05, 0.09, 0.14
Shows system hostname
[root@web-server ~]# hostname
web-server.novalocal
Display IP address of host
[root@web-server ~]# hostname -i
fe80::f816:3eff:fee7:bf9b%eth0 172.25.1.104
Shows system reboot history
[root@web-server ~]# last reboot
reboot system boot 3.10.0-229.4.2.e Wed May 20 18:11 - 09:35 (17+15:24)
reboot system boot 3.10.0-123.9.3.e Wed May 20 13:00 - 18:10 (05:10)
reboot system boot 3.10.0-123.9.3.e Tue Feb 24 17:59 - 18:10 (85+00:11)
reboot system boot 3.10.0-123.9.3.e Wed Nov 19 11:09 - 18:10 (182+07:01)
reboot system boot 3.10.0-123.9.3.e Sun Nov 16 14:36 - 11:09 (2+20:32)
reboot system boot 3.10.0-123.9.3.e Fri Nov 14 14:54 - 11:09 (4+20:15)
reboot system boot 3.10.0-123.8.1.e Fri Nov 14 12:45 - 14:53 (02:08)
Shows current date and time
[root@web-server ~]# date
Sun Jun 7 09:37:40 IST 2015
Shows current date and time in UTC
[root@web-server ~]# date --utc
Sun Jun 7 04:07:56 UTC 2015
Shows calendar of the month
[root@web-server ~]# cal
June 2015
Su Mo Tu We Th Fr Sa
1 2 3 4 5 6
7 8 9 10 11 12 13
14 15 16 17 18 19 20
21 22 23 24 25 26 27
28 29 30
Display who is logged in
[root@web-server ~]# w
09:38:56 up 17 days, 15:27, 1 user, load average: 0.08, 0.12, 0.14
USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT
cloud-us pts/0 x.x.x.x 09:35 0.00s 0.10s 0.14s sshd: cloud-user [priv]
Display who you are logged in as
[root@web-server ~]# whoami
root
—
Swapnil Jain [RHCA, RHCI, CEH]
Swapnil (at) linux (dot) com
