Basic Bash Commands on Linux OS

July 29, 2021

Linux is an open-source family of Unix operating systems based on the Linux Kernel. There are several variants in linux systems such as Ubuntu, Fedora, Mint, Debian, and others. These systems are more accurately referred to as distributions or distributions.

Since it was first released in 1991, Linux's popularity has skyrocketed due to its open-source nature. Users are free to modify Linux and distribute it under their own name.

Linux Basic Command

Here's a list of basic Linux commands:

1. Looping

This command is used to create loops in bash scripts.

#!/bin/bash
echo "Bash version ${BASH_VERSION}"
for i in {0..10..2}
do
  echo "welcome $i times"
done

2. Alias

This command is used to manipulate bash commands

alias c='clear'
alias blog='cd /home/alex/blog'

# to cancel the alias command can use:
unalias c
unalias blog

3. Privileged Access

To use the alias command without using the root command.

if [ $UID -ne 0 ]; then
  alias update='sudo apt-get update'
  alias upgrade='sudo apt-get upgrade'
fi

4. Select Case

To select according to the specified parameters.

_myos="$(uname)"

case $_myos in
  Linux) echo "Ini OS Linux";;
  Microsoft) echo "Ini OS Microsoft";;
esac

5. Command History

To see a list of command usage.

history

6. Time and Date

To display the current date and time.

# show complete date and time 
date

# show time
date +"%T"

# show date
date +"%d-%m-%Y"

7. Network Ping

To check whether the network exists or not.

ping 192.168.43.1 -c 5

8. Check Open Port

To check open network ports.

netstat -tulanp

9. Firewall Control

To check the network firewall with iptables.

# all data
sudo iptables -L -n -v --line-numbers

# input command
sudo iptables -L INPUT -n -v --line-numbers

# output command
sudo iptables -L OUTPUT -n -v --line-numbers

# forward command
sudo iptables -L FORWARD -n -v --line-numbers

10. Halt/Reboot/Shutdown

System shutdown command.

sudo /sbin/reboot
sudo /sbin/poweroff
sudo /sbin/halt
sudo /sbin/shutdown

11. Web Server Control

To reload and test the web server.

# nginx web server
nginx -s reload
nginx -t

# lighttp web server
lighttpd reload
lighttpd -f /etc/lighttpd/lighttpd.conf -t

# apache web server
apachectl -k graceful
apachectl -t

12. Playing Music/Video

To play multimedia files.

# mp3 list all
mplayer *.mp3

# mp3 shuffle
mplayer --shuffle *.mp3

13. Check Wireless Interface

To view the details of the wireless interface.

iwconfig wlan0

14. Memory, CPU, Hardware

To view memory details, cpu and hardware list.

# check memori
free -m -l -t

# check cpu
lscpu

# check hardware
lscpi

15. Disk, Task Manager, Memcached

To view disk details, task manager and memcached.

#disk usage 
df -H

# dish total
du -ch

# task manager
htop

# memcached status
memcached-tool 10.10.27.11:11211 stats
memcached-tool 10.10.27.11:11211 display

# quickly flush out memcached server
echo "flush_all" | nc 10.10.10.27.11:11211

---

author : doctor. moeclay