Linux -FileCommands

 
cat :- read/write/apend a file
rm :- Delete a file
cp :- Copy a file from source to destination directory
mv :- Move or rename a file from source to destination directory
vi,nano :- These are the Text editors to create or modify a file

touch :- Create an empty file

1. To Read or display the content of a file

    $ cat <<filename>>
    ## To read file1
    $ cat file1

2. To Read or display the content of multiple files

    # To print content of file1 then file2
    $ cat file1 file2
    # To print content of all txt files
    $ cat *.txt

3. To view the file content with line number

    $ cat -n file1

4. To create a new file ( after finishing writing in file press Enter and then CTRL + C)

    $ cat > file1

5. To Copy the content of a file to another file

    # to copy content of file1 to file2
    $ cat file1 > file2
    # To merge content of multiple files file1,file2.file3 into file4
    $ cat file1 file2 file3 > file4

6. To Append the content of a file to another file

     # to append the content of file1 to file2
    $ cat file1 >> file2  

7. To Append new content to a file ( after finishing writing in file press Enter and then CTRL + C)

      
    $ cat >> file1 

Examples ( Assume all the directories in below examples exists)

Create an empty file (App01.txt) under /tmp/test/testingTypes/unitTest directory

 touch /tmp/test/testingTypes/unitTest/App01.txt

Create 2 more empty filess (App02.txt and App03.txt) under /tmp/test/testingTypes/unitTest directory

  cd /tmp/test/testingTypes/unitTest
  touch App02.txt App03.txt

Copy App03.txt file to /home/ubuntu directory

cp App03.txt /home/ubuntu/.

Add some data inside /home/ubuntu/App03.txt file and read the contents

cd /home/ubuntu
echo "This is test case 3" >> App03.txt
cat App03.txt

Delete the App03.txt file from /tmp/test/testingTypes/unitTest

rm /tmp/test/testingTypes/unitTest/App03.txt

Move /home/ubuntu/App03.txt to /tmp/test/testingTypes/unitTest

mv App03.txt /tmp/test/testingTypes/unitTest/App03.txt

Open /tmp/test/testingTypes/unitTest/App02.txt in vi editor and add some text into this file(:wq! save and exit and :q! for quit without save)

 vi /tmp/test/testingTypes/unitTest/App02.txt

Remove all txt files under /tmp/test/testingTypes/unitTest

rm  /tmp/test/testingTypes/unitTest/*.txt