Most used Linux commands when working on servers / when ssh to remote systems

tail -100f catalina.out

let's say we want to run the latest current running logs with last 100 lines, then you should use the above command.

cd <specific folder>

useful to change to mentioned directory

cd ..

useful to change back to parent directory, one level down

mkdir <dir_name>

creates a new directory with given name <dir_name>

mkdir -p <dir1/dir2/dir3>

creates the directory structure, which fails to do without -p option

rm -r <dir1/dir2/dir3>

removes the complete directory structure, regardless of number of internal directories, which fails to remove without -r option.