Basic concepts of linux
Day 4
Hello everyone welcome back !!!
Myself Swanik Santosh Gudekar and I am back with my blog. This is the fourth blog of Linux series. Today I attended the fourth session conducted by Master Pranav Jambare. It was a fun and exciting session.
Points Covered in This Session :
Find and Locate
Secure Shell
Find and Locate :
Find :
The find command is to search the specified files in all of your computer's directories.
The find command is a more aggressive search tool than locate or which.
Using the file command we can search for files by name, owner, group, permissions, type, size, time modified, date and various other criteria.
The find command is highly efficient but this efficiency comes at a cost of time.
It produces real time output.
SYNTAX : find <where to start search> <what to find> <-options> <file/directory name>
Locate :
Locate command is used to find files and directives quickly.
This command is a more convenient and efficient alternative to the find command.
The locate command doesn't search the entire file system , but looks through a regularly updated file database in the system .
It is faster than find command but may not provide real-time outputs.
Locate command works better and faster than the find command.
SYNTAX : locate <file name>
Secure shell :
The SSH command provides a secure encrypted connection between two hosts over an insecure network.
SSH is a network protocol that enables secure remote connections between two system.
It is used to manage machines, copy, or move files between systems.
It is a secured remote access protocol and works on port no 22.
It transfers the data in an encrypted format.
There are two keys available in the ssh for encryption and decryption :
- Public key :
The public key is used for encryption and can be freely shared with others.
When someone wants to send you encrypted data, they will use your public key to encrypt it.
Its mechanism is slow.
It can be given to anyone with whom an individual wants to communicate.
- Private Key :
The private key is a secret key and can not be shared with anyone. This key is used to decrypt the received data.
The private key is used for both encrypting and decrypting sensitive data.
A user's private key is a key kept secret by the SSH user on his/her client machine.
The private key mechanism is faster.
There are two important package for creation of SSH connection :
openssh-client
openssh-server
SYNTAX :
Installing package : yum install <package name> -y
Check port : netstat -tumlp|grep 22
Check service status : systemctl status <service name>
SSH configuration file : vi /etc/ssh/sshd_config
To allow and deny user to connect to a specify user :
Allow : vi /etc/host.allow
Deny : vi /etc/host.deny
These were the topics covered by Master Pranav Jambare in the fourth session of Linux.
