New to Linux or support hundreds of servers? Here are my top-10 favorite linux commands/one liners.

  • df -h - defacto for seeing how much drive space is per file system, used, available, percentage, and where it is mounted.

    ➜  ~ df -h
Filesystem             Size  Used Avail Use% Mounted on
udev                   6.8G     0  6.8G   0% /dev
tmpfs                  1.4G  2.2M  1.4G   1% /run
/dev/mapper/data-root  450G  157G  271G  37% /
tmpfs                  6.9G  173M  6.7G   3% /dev/shm
tmpfs                  5.0M     0  5.0M   0% /run/lock
tmpfs                  6.9G     0  6.9G   0% /sys/fs/cgroup
/dev/nvme0n1p2         4.0G  2.1G  2.0G  52% /recovery
/dev/nvme0n1p1         498M  187M  311M  38% /boot/efi
tmpfs                  1.4G   20K  1.4G   1% /run/user/110
tmpfs                  1.4G   96K  1.4G   1% /run/user/1000
/dev/sda1              916G   45G  825G   6% /media/bryanlurer/1tb_ssd

  • sysinfo - Well this one is a script for me.. GITHUB LINK HIER. I just type sysinfo and it gives me the details I need.

    ➜  ~ sysinfo
Username: bryanlurer
Hostname: a300
External IP: 123.456.789.12
Weather: San Miguel, Philippines: ⛈ +32°C
Load:  1.34 0.51 0.42 1/1397 21739

  • curl v2.wttr.in - Weather in your terminal! Lots of formatting options for one liner, such as in the sysinfo command.

  • apti - Ubuntu/Debian - An alias for the following: sudo apt update -y ; sudo apt install -y

  • yumi - RHEL/CentOS/Amazon Linux - An alias for the following: sudo yum update -y ; sudo yum install -y

  • wavemon - If you have wifi it will show signal, link quality, signal over time, which frequency you are using. A fantastic CLI tool for Linux.

  • ssh user@host(name or IP) - connects to host as user

  • ssh -p <port> user@host(name or IP) - connects to host on specified port as specified user

  • ssh-copy-id user@host - adds your ssh key to host for passwordless login - should be standard!

  • passwd - Change your password

  • date - Shows the current date and time.

    [ec2-user@ip-172-26-6-216 ~]$ date
Sun Jul 19 02:15:21 UTC 2020

  • uptime - Shows system uptime and load average.

    [ec2-user@ip-172-26-6-216 ~]$ uptime
02:14:34 up 2 min,  2 users,  load average: 0.04, 0.04, 0.01

  • w - Displays who is logged in, duration, and ip

    [ec2-user@ip-172-26-6-216 ~]$ w
02:13:26 up 0 min,  2 users,  load average: 0.15, 0.06, 0.02
USER     TTY      FROM              LOGIN@   IDLE   JCPU   PCPU WHAT
ec2-user pts/0    vps-722c62c5.vps 02:12   30.00s  0.00s  0.00s -bash
ec2-user pts/1    1.2.3.4   02:13    1.00s  0.00s  0.00s w

  • uname -a - Shows kernel information

    [ec2-user@ip-172-26-6-216 ~]$ uname -a
Linux ip-172-26-6-216 4.14.181-108.257.amzn1.x86_64 #1 SMP Wed May 27 02:43:03 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

  • man {command} - Shows the manual for specified command. ``` [ec2-user@ip-172-26-6-216 ~]$ man ls … LS(1) User Commands LS(1)

NAME ls - list directory contents

SYNOPSIS ls [OPTION]… [FILE]…

DESCRIPTION List information about the FILEs (the current directory by default). Sort entries alphabetically if none of -cftuvSUX nor –sort is specified.


* `du -h {file/dir}`  - Shows the disk usage of the files and directories.

[ec2-user@ip-172-26-6-216 ~]$ du -h 8.0K ./.ssh 668M .


* `ps -u {user}` - lists your processes

[ec2-user@ip-172-26-6-216 ~]$ ps -u ec2-user PID TTY TIME CMD 2800 ? 00:00:00 sshd 2801 pts/0 00:00:00 bash 2830 ? 00:00:00 sshd 2831 pts/1 00:00:00 bash 2887 pts/1 00:00:00 ps



* `curl` - Transfers data.

[ec2-user@ip-172-26-6-216 ~]$ curl -s ifconfig.me 52.52.52.52

* `wc -l` - Counts lines in a file:

[ec2-user@ip-172-26-6-216 ~]$ wc -l important_data.txt 71721955 important_data.txt


* `ping {host/ip}` - Pings host and outputs results. Will continue forever unless `-c {#}` is provided.

[ec2-user@ip-172-26-6-216 ~]$ ping 1.1.1.1 -c 5 PING 1.1.1.1 (1.1.1.1) 56(84) bytes of data. 64 bytes from 1.1.1.1: icmp_seq=1 ttl=49 time=1.18 ms 64 bytes from 1.1.1.1: icmp_seq=2 ttl=49 time=1.23 ms 64 bytes from 1.1.1.1: icmp_seq=3 ttl=49 time=1.23 ms 64 bytes from 1.1.1.1: icmp_seq=4 ttl=49 time=1.21 ms 64 bytes from 1.1.1.1: icmp_seq=5 ttl=49 time=1.23 ms

— 1.1.1.1 ping statistics — 5 packets transmitted, 5 received, 0% packet loss, time 4005ms rtt min/avg/max/mdev = 1.183⁄1.219⁄1.234⁄0.036 ms ```

And that is it for now. What commands are your favorites and most useful?