CHEAT SHEET FOR UNIX

Introduction–Cheatsheet for UNIX

UNIX is a group of multi-user and multifamily operating systems that was originally derived from AT&T UNIX. Its research development was initially started at AT&T Bell Laboratory Research Center in the 1970s. It was developed by Dennis Ritchie, Ken Thompson, Brian Kernighan, Joe Ossanna and Douglas McIlroy at Bell Labs. It was initially released in the year 1971. It was licensed under the free and open source and some features under a proprietary license. The default user interfaces are Graphical User Interface (GUI) and Command Line Interface (CLI). It was written completely in Assembly Language and C programming language. It was presented with a Turing Award.

In this Cheat sheet for UNIX article, we will discuss what UNIX is and the different UNIX commands.

Cheat sheet for UNIX Commands and Content:

UNIX commands can often be differentiated or grouped into different categories of powerful commands such as File Commands, Process Management commands, Compression, Network related, File Permissions, Searching and SSH related. Below are the list of Cheat sheet for UNIX commands which perform different kinds of functionalities and operations in UNIX operating system are as follows:

UNIX commands	Description
FILE I/O
ls	To list the directory.
pwd	To show the current directory.
mkdir folder	To create a new directory with the name folder
cp f1 f2	To copy file f1 to file f2
mv f1 f2	To move file f1 to file f2 if there exists a file named f2
rm f1	To delete a file named f1
rm –r file	To remove a file forcefully
rm –r dir	To delete a directory named dir
rm –rf dir	To forcefully remove a directory named dir
rm –f f1	To forcefully remove a file named f1
touch file	To create or update a file
more file	To print the contents of a file as output
head file	To print the contents of the first 10 lines of the file as output
tail file	To print the contents of the last 10 lines of the file as output
PROCESS COMMANDS
ps	To display all the currently active processes in the OS
kill pid	To kill the process with the mentioned process id as pid
fg	To bring the recently running job to foreground
bg	To list all the current background running processes or jobs
top	To display all the running processes.
NETWORK
ifconfig	To list down all the network-related details such as all the assigned IP addresses IPv4 and IPv6, network interfaces etc.,
netstat	To list down all the ongoing connections in the local system and the details of ports being listened to and the services those are waiting for requests.
nslookup	To query the DNS lookup and find the related details.
hostname	To know the details of the hostname and IP address mapped.
SEARCHING
find	To search the files in the directory specified.
grep	To search the selected lines in all the files that match the given pattern.
grep	To search for the pattern in given lines.
grep –rn	To search the pattern recursively for the pattern in a given directory including the line number.
grep –r	To search the pattern recursively for the pattern in given directory.
command | grep	To search for the pattern in the given output of the command.
Locate file	To find all the instances of the file using an index-based system of the database that is built of updated command.
Find file	To find all the occurrences of a file in the real system file directory.

 

TIPS & TRICKS OF USING CHEAT SHEET FOR UNIX COMMANDS:

1. The UNIX operating system has a kernel that is the core part of the system that coordinates the entire functionalities to perform different operations.

2. It has a Shell that processes the utility requests by interpreting the UNIX commands provided in the terminal by the user.

3. The entire data in the cheat sheet UNIX is organized in a file system.

4. The login command will be used to login to the UNIX system as a valid user before performing any operation, whereas log out is the command to log out from the system as a user.

5. Shell Scripting is the way of programming that is being carried on cheat sheet UNIX to execute the shell scripts (a series of commands) by the Kernel in UNIX Operating System.

6. The file system security in UNIX is based on the access rights of the user such as R, W or X which are called R – Read permission, W – Write Permission, X – Execute Permission.

7. There are different commands for access rights of a user in a UNIX system.