11 important Linux command names explained

You can play with these commands by rapidly spinning up an Ubuntu container with Docker.

docker run -it ubuntu bash

#cat

#Explanation

Name is derived from its function to concatenate files.

#Functionality

Display contents of a file:

echo "Hello, World!" >> sample.txt
cat sample.txt

# Hello, World!

Concatenate two text files and write them to a new file:

echo "Hello, " >> a.txt
echo "World!" >> b.txt
cat a.txt b.txt > combined.txt
cat combined.txt

# Hello, World!

#cd

#Explanation

Stands for "change directory".

#Functionality

Change the current working directory.

#chmod

#Explanation

Stands for "change mode" (permissions of file system objects are sometimes known as modes).

#Functionality

Change the access permissions of a file or directory.

#compgen

#Explanation

Stands for "completion generation".

#Functionality

A built-in command for auto-completion in Bash, which is called on pressing TAB key twice.

#cp

#Explanation

Stands for "copy".

#Functionality

Copy files and directories.

echo "Hello, World!" >> sample.txt
cp sample.txt copy.txt
cat copy.txt

# Hello, World!

#curl

#Explanation

Stands for "client URL".

#Functionality

Transfers data from or to a server. Supports most protocols, including HTTP, FTP, and POP3.

curl https://swapi.dev/api/planets/1/

# {"name":"Tatooine"}

Installation instructions.

#grep

#Explanation

Stands for "global regular expression print".

#Functionality

Find patterns in files using regular expressions.

echo "Hello, World!" >> sample.txt
grep "Hello" sample.txt

# [Hello], World!

#ls

#Explanation

Stands for "list".

#Functionality

List directory contents.

#man

#Explanation

Stands for "manual".

#Functionality

Format and display manual pages.

#pwd

#Explanation

Stands for "print work directory".

#Functionality

Print name of current/working directory.

pwd

# /

cd home

# /home

#top

#Explanation

Stands for "table of processes"

#Functionality

Get the information of running tasks, memory, cpu, and swap.