Linux commands

sudo su
Change to root user
cat filename.txt
Reads the contents of filename.txt file
cat >> filename.txt
Write to filename.txt. If the file exists, it will be emptied but if the file does not exists, it will be created. Use ctrl+d to exit.
gedit helloWorld.txt
helloworld.txt file will be opened in edit mode
nano helloWorld.txt
helloworld.txt file will be opened in edit mode
free -hm
Displays the free space in memory(RAM)
top
Displays all the process in run and the usage of memory and CPU in percentage
zip -r temp.zip Documents
If you want to archive a folder named “Documents” in a zip file named “temp.zip”.
mv file1 /tmp
To move the file file1 from the current working directory to the /tmp directory.