- Cat command : Cat command is used to display contents of the file
For example here we are using echo command to write/print "Hello World" in the file where in our first file which is called as first.txt to create our first file we use > sign .
Now using cat command we will display contents in the file in our case it is Hello World.
To change Persmission of File : (chmod) :- This command is used to change the permission of the file. For this you should be either superuser or Admin to change its respective permissions.
Basic syntax of chmod is : chmod [option] [permission] [file_name]
chmod 777 first.txt
777 : All users can read,Write and execute the file
775 : command will grant the read, write, and execute permissions to the owner of the file or directory and to the group associated to it.
To check which commands you have run till now
history : history command is used to check which commands you have run till now.
To remove a directory/ Folder
To remove a directory/folder use rm command
Option to confirm before deleting each file use : rm -i file_name
To remove files without prompting use -f (here -f is nothing but forcefully remove those files/directories) : rm -f file_name
To remove non empty directories/files without being prompted you can use -rf : rm -rf file_name
- To create a fruits.txt file and to view the content
We are using touch command to create fruits.txt and to display contents from that file we will be using cat command
- Add content in fruits.txt (One in each line) - Apple, Mango, Banana, Cherry, Kiwi, Orange, Guava
To add contents in fruits.txt we will use vim command , so vim fruits.txt
press enter after that you will redirected to terminal press i to write the fruits name as
Now type all the fruits name as shown below , once you are done press escape and hit : and type wq that will save your file and you will be prompted to the terminal .Now to view contetnts of the file use cat command again
To Show only top three & bottom three fruits from the file.
To show top three fruits we will be using head command to display top 3 fruits . Similalry we will use tail command to display bottom 3 fruits from the file such as:
To create another file Colors.txt and to view the content
Similarly to create colors.txt we will follow the same set of commands
touch colors.txt
To display contents of that file we will use cat colors.txt
- Add content in Colors.txt (One in each line) - Red, Pink, White, Black, Blue, Orange, Purple, Grey.
Now lets add more contents to the file using the following commands
To view contents of the file we will use cat command again as
To find the difference between fruits.txt and Colors.txt file
To find differnece between two file we will use diff commands
To learn more linux refer this video