Java Blog: Useful linux commands

In this page we show the most useful linux commands:

Grep Recursive

find . -name \* -exec grep "Search" {} \;

Find by name

find . -name filename

Disk Usage Space

df -h

Start SSH service

sudo service ssh start

Symbolic link

ln -s {target-filename} {symbolic-filename}

Create a symbolic link from "myfolder" to "/home/destination" folder:

ln -s /home/destination myfolder

SSH Tunnel WEB

Suppose you have three machines:

user1@address1;
user2@address2;
user3@address3.

You are interested into make a communication between user1@address1 to user3@address3 through an SSH tunnel web on the user2@address2 machine.

You have to open a shell on user1@address1 machine and write

 sudo  ssh -N -L 1522:localhost:8000 user2@address2

Next you have to open a shell on user3@address3 machine and write

sudo  ssh -N -L 8000:localhost:80 user3@address3

Now if you open you browser on user1@address1 machine and access to http://localhost:1522/, you are able to access to a service that runs on the port 80 on user3@address3 machine