Some common usages of cat command

1) To view a single file 
Command: 
 

$cat filename

Output 
 

It will show content of given filename

 

2) To view multiple files 
Command: 

 

 

$cat file1 file2

Output 
 

This will show the content of file1 and file2.

 

 

3) To view contents of a file preceding with line numbers. 
Command: 
 

$cat -n filename

Output 
 

It will show content with line number

example:-cat -n  geeks.txt

1)This is geeks

2)A unique array

 

4) Create a file 
Command: 
 

$ cat > newfile

Output 
 

Will create a file named newfile

 

5) Copy the contents of one file to another file. 
Command: 
 

$cat [filename-whose-contents-is-to-be-copied] > [destination-filename]

Output 
 

The content will be copied in destination file

 

6) Cat command can append the contents of one file to the end of another file. 
Command: 
 

$cat file1 >> file2

Output 
 

Will append the contents of one file to the end of another file

7) Cat command can display content in reverse order using tac command. 
Command: 
 

 $tac filename

Output 
 

Will display content in reverse order 

8) Cat command to merge the contents of multiple files. 
Command: 
 

$cat "filename1" "filename2" "filename3" > "merged_filename"

Output 
 

Will merge the contents of file in respective order and will insert that content in "merged_filename".

9) Cat command to display the content of all text files in the folder. 
Command: 
 

$cat *.txt

Output 
 

Will show the content of all text files present in the folder.

 

10) Cat command can suppress repeated empty lines in output 
Command: 
 

$cat -s geeks.txt

Output 

Will suppress repeated empty lines in output

Source:https://www.geeksforgeeks.org/cat-command-in-linux-with-examples/