Learn Useful Linux Commands for System Administrators

In this article, we are going to learn Useful Linux Commands for System Administrators that are utilized in their day by day life. This is anything but a total yet it’s a smaller rundown of commands to allude when required. Allow us to begin individually how we can utilize those commands with examples.

Learn Useful Linux Commands for System Administrators

Learn Useful Linux Commands for System Administrators

Follow the below Article for Useful Linux Commands for System Administrators:

1. Uptime Command

The Linux Operating System is loaded up with a few commands which any hopeful Linux master or power user for example system admin should have a decent handle of. One of such commands is uptime and today, I’ll momentarily examine its purpose and syntax.

Uptime Command In Linux: It is used to find out how long the system is active (running). This command returns a set of values that involve, the current time, and the amount of time the system is in running state, the number of users currently logged into, and the load time for the past 1, 5, and 15 minutes respectively.

# uptime

08:16:26 up 22 min,  1 user,  load average: 0.00, 0.03, 0.22

2. W Command

w command in Linux is utilized to show who is signed on and what they are doing. This command shows the data about the users right now on the machine and their processes. The header shows, in a specific order, the current time, how long the system has been running, the number of users are right now signed on, and the system load averages for as far back as 1, 5, and 15 minutes. The accompanying passages are shown for every client: login name, the tty name, the distant host, login time, inactive time, JCPU, PCPU, and the order line of their present interaction. The JCPU time is the time utilized by all cycles joined to the tty. It does exclude past background jobs however incorporates right now running background jobs. The PCPU time is the time utilized by the current process, named in the “what” field.

The w command gives information data about right now logged-in users.

$ w

11:24:37 up  2:04,  1 user,  load average: 2.04, 1.95, 1.74
USER          TTY      FROM             [email protected]   IDLE   JCPU   PCPU WHAT
itsmarttricks tty7     :0               09:21    2:04m  7:52   0.52s xfce4-session

3. Users Command

Users command displays currently logged in users. This command don’t have other parameters other than help and version.

# users

itsmarttricks

4. Who Command

who command just return user name, date, time and host information data. who command is like w command. Dissimilar to w command who doesn’t print what users are doing. Lets delineate and see the distinctive among who and w commands.

# who

itsmarttricks  pts/0        2021-09-18 07:59 (192.168.50.1)
# w

08:43:58 up 50 min,  1 user,  load average: 0.64, 0.18, 0.06
USER           TTY      FROM              [email protected]   IDLE   JCPU   PCPU WHAT
itsmarttricks  pts/0    192.168.50.1     07:59    0.00s  0.43s  0.10s w

Who command Options

  • -b : Displays last system reboot date and time.
  • -r : Shows current runlet.
  • -a, –all : Displays all information in cumulatively.

5. Whoami Command

In computing, whoami is a command found on most Unix-like operating systems, Intel iRMX 86, every Microsoft Windows operating system since Windows Server 2003, and on ReactOS. It is a concatenation of the words “Who am I?” and whoami command print the name of current user. You can also use “who am i” command to display the current user. If you are logged in as a root using sudo command “whoami” command return root as current user. Use “who am i” command if you want to know the exact user logged in.

# whoami

itsmarttricks

6. ls Command

ls command display list of files in human readable format.

# ls -l

total 114
dr-xr-xr-x.   2 root root  4096 Sep 21 08:46 bin
dr-xr-xr-x.   5 root root  1024 Sep  10 15:49 boot

Sort file as per last modified time.

# ls -ltr

total 40
-rw-r--r--. 1 root root  6546 Sep 21 18:42 install.log.syslog
-rw-r--r--. 1 root root 22435 Sep 21 18:45 install.log
-rw-------. 1 root root  1003 Sep 21 18:45 anaconda-ks.cfg

For more examples of ls command, please check out our article on Best Linux Ls Command With Examples.

7. Crontab Command

List schedule jobs for current user with crontab command and -l option.

# crontab -l

00 10 * * * /bin/ls >/ls.txt

Edit your crontab with -e option. In the below example will open schedule jobs in VI editor. Make a necessary changes and quit pressing :wq keys which saves the setting automatically.

# crontab -e

8. Less Command

less command allows quickly view file. You can page up and down. Press ‘q‘ to quit from less window.

# less install.log

Installing setup-2.8.14-10.el6.noarch
warning: setup-2.8.14-10.el6.noarch: Header V3 RSA/SHA256 Signature, key ID c105b9de: NOKEY
Installing filesystem-2.4.30-2.1.el6.i686
Installing ca-certificates-2010.63-3.el6.noarch
Installing xml-common-0.6.3-32.el6.noarch
Installing tzdata-2010l-1.el6.noarch
Installing iso-codes-3.16-2.el6.noarch

Also Read – Learn Basic Linux System Commands For Linux Foundation Certified IT Associate (LFCA) Certification

That’s all, In this article, we have explained Useful Linux Commands for System Administrators. If you like this article, then just share it and then do subscribe to email alerts for Linux, Windows, macOS, Android, Internet, Firewall and Security, CCTV tutorials. If you have any questions or doubts about this article, please comment.

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ITSmarttricks Team

This is Mangesh Dhulap the Founder and Editor of IT SMART TRICKS have 6+ years of Industrial Experience. We expect from our visitors to like, share, and comment on our posts.

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