List Of Usefull BASH Commands

# Bash Commands.md

    BASH COMMANDS COLLECTION

  1.Bash Alias's

• Basic Alias's
• HTTD Service
• Mysql Service

  2.Mysql

• Uninstalling in Ubuntu
• Mysql Service Alias

  3.Parent Proccess Kill

  4.SCP Commands

  5.SSH

• Connecting To Remote nix
• Connecting To Remote nix without password
• Connecting To Remote nix with name ,no need of ip

  6.Screen

  7.Open Terminal in Context Menu

  8.Checking which Systems are up in network

  9.Open Terminal in Context Menu

  10.Firewall & Ports

  11.Vim

1.List Of Alias.md

alias c="clear"; # clear screen alias e="exit"; # exit session

Alias For HTTD Service Monitoring

alias hs="sudo service httpd status"; alias ha="sudo service httpd start"; alias hb="sudo service httpd restart"; alias hc="sudo service httpd stop";

Alias For MYSQLD Service Monitoring

alias ms="sudo service mysqld status"; alias ma="sudo service mysqld start"; alias mb="sudo service mysqld restart"; alias mc="sudo service mysqld stop"; alias mysql="sudo mysql";

11.Vim.md

Saving a read-only file in vi/vim

By usig following commands we can save a file in read-only

1.":w !sudo tee % " 2.Click on 'O' or 'L'

Link : http://www.geekyboy.com/archives/629

2.Mysql.md

To check which version is there

dpkg -l | grep mysql

Uninstalling mysql

from ubuntu

sudo apt-get remove --purge mysql-server mysql-client mysql-common sudo apt-get autoremove sudo apt-get autoclean

Alias For MYSQLD Service Monitoring

From Centos 6

alias ms="sudo service mysqld status"; alias ma="sudo service mysqld start"; alias mb="sudo service mysqld restart"; alias mc="sudo service mysqld stop"; alias mysql="sudo mysql";

How to Install MySQL 5.5 on Ubuntu Server 12.04 LTS

sudo apt-get update sudo apt-get install mysql-server-5.5

Once installation has completed, you just need to check that mysql is running. To do this, run

sudo netstat -tap | grep mysql

Checking which Systems are up in network

# Checking which systems are up in network
#!/bin/bash

for i in 192.168.0.{1..256}; 
do 
	if ping -c1 -w1 $i &>/dev/null
	then
		echo $i is up
	fi
done

Firewall.md

Firewall Opertion Manual ( Tested In Ubuntu 14.04) By Lakshman.Javvadi

For Referance : https://help.ubuntu.com/lts/serverguide/firewall.html

1.Enable Firewall

First 'ufw' needs to be enabled. From a terminal prompt enter

 sudo ufw enable

2.To open a port (ssh in this example):

sudo ufw allow 22

3.Adding Rules

Rules can also be added using a numbered format

sudo ufw insert 1 allow 80

4.Similarly, to close an opened port:

sudo ufw deny 22

5.Remov Port Rule

To remove a rule, use delete followed by the rule:

sudo ufw delete deny 22

6.Allowing Specific Port

It is also possible to allow access from specific hosts or networks to a port. The following example allows ssh access from host 192.168.0.2 to any ip address on this host:

sudo ufw allow proto tcp from 192.168.0.2 to any port 22

Replace 192.168.0.2 with 192.168.0.0/24 to allow ssh access from the entire subnet.

7. --dry-run option

Adding the --dry-run option to a ufw command will output the resulting rules, but not apply them. For example, the following is what would be applied if opening the HTTP port:

sudo ufw --dry-run allow http

8. ufw disabled

ufw can be disabled by:

sudo ufw disable

9. Firewall Status

To see the firewall status, enter

sudo ufw status

10.Verbose

And for more verbose status information use:

sudo ufw status verbose

11. Numbered Port Format

To view the numbered format:

sudo ufw status numbered

Open Terminal in Context Menu

# Following commands will add "Open Terminal" menu item in Ubuntu Right Click context menu
# Tested in Ubuntu 12.04 & 14.04


sudo apt-get install nautilus-open-terminal  && nautilus -q

Parent Proccess Kill

## Parent Proccess Kill
 
pkill -9 -f processname
 
Ex: pkill -9 -f gedit

Prompt Name & Customizations

## Change the prompt


PS1='\n \u $reset_color→ \w \n \n';
 
\n : new line
\u : user name
\w : path
$reset_color→ :To generate right arrow
 
Example : 
 
1)  lakshman → ~ 
2)  lakshman → /var/mail 

Root Access To Folder

Add “Open as Root/Administrator” Option in Ubuntu 14.10


sudo add-apt-repository ppa:noobslab/apps
 sudo apt-get update
 sudo apt-get install open-as-administrator
 
 
 nautilus -q

SCP Remote File

## Copy Remote File To Local Machine

scp -r <user>@<hostname>:<file/folder> <destination>
 
-r : recursively copies files and folders


ex: scp -r root@tv:/var/www/html ./


## Copy the file "foobar.txt" from a remote host to the local host
`$ scp [email protected]:foobar.txt /some/local/directory`
 
## Copy the file "foobar.txt" from the local host to a remote host
`$ scp foobar.txt [email protected]:/some/remote/directory`
 
## Copy the directory "foo" from the local host to a remote host's directory "bar"
`$ scp -r foo [email protected]:/some/remote/directory/bar`
 
## Copy the file "foobar.txt" from remote host "rh1.edu" to remote host "rh2.edu"
`$ scp [email protected]:/some/remote/directory/foobar.txt [email protected]:/some/remote/directory/`
 
## Copying the files "foo.txt" and "bar.txt" from the local host to your home directory on the remote host
`$ scp foo.txt bar.txt [email protected]:~`
 
## Copy the file "foobar.txt" from the local host to a remote host using port 2264
`$ scp -P 2264 foobar.txt [email protected]:/some/remote/directory`
 
## Copy multiple files from the remote host to your current directory on the local host
`$ scp [email protected]:/some/remote/directory/\{a,b,c\} .`
`$ scp [email protected]:~/\{foo.txt,bar.txt\} .`

Screen

Screen Command

KeyBind + Combination Key Action Description 

Ctrl+b	%	Split the current window vertically into two panes
Ctrl+b	:split-window	Horizontally split window or current pane
Ctrl+b	o	Switch to the next pane
Ctrl+b	c	Open new window
Ctrl+b	l	Move to previous window
Ctrl+b	n	Move to next window
Ctrl+b	p	Move to previous window
Ctrl+b	d	Detach current client
Ctrl+b	x	Kill the current pane
Ctrl+b	&	Kill the current window
Ctrl+b	,	Rename the current window
Ctrl+b	q	Display pane numbers
Ctrl+b	?	List all keybindings
Ctrl+b	{	Move the current pane to previous
Ctrl+b	}	Move the current pane to next
Ctrl+b	:break-pane	Detach pane into its own window
Ctrl+b	w	List all windows
Ctrl+b	0-9	To select window


Ctrl+b :resize-pane Resize current pane down by default
Ctrl+b :resize-pane -U Upward Resize current pane
Ctrl+b :resize-pane -R Resize current pane to right
Ctrl+b :resize-pane -L Resize current pane to left 
Ctrl+b :resize-pane 40 Resize current pane down by 40 cells 
Ctrl+b :resize-pane -L 40 Resize current pane left by 40 cells 
Ctrl+b :resize-pane -R 40 Resize current pane right by 40 cells
Ctrl+b :resize-pane -U 40 Resize current pane upward by 40 cells 
Ctrl+b :resize-pane -t -L 40 Resize pane with id of 2 left by 40 cells
Ctrl+b :resize-pane -t 2 40 Resize pane with id of 2 down by 40 cells

SSH

## Connecting to remote nix system

Syntax : ssh user@remote_ip 

Ex: ssh [email protected]


## Connecting to remote nix system without password

1.Genarate ssh-keygen with typeing this command 'ssh-keygen' and give info like ssh file name and password

Syntax : ssh-keygen

2.Then use 'ssh-copy-id'  command to copy ssh key to remote system 


Syntax : ssh-copy-id user@remote_ip

Ex: ssh-copy-id [email protected]

3.Now type ssh with remote user name and ip 

Ex : ssh [email protected]


## Connect To Remote System with name ,no need of ip

##If you only want the name for ssh and ssh only, you can add a name to your ssh config in ~/.ssh/config

Syntax :

       File : ~/.ssh/config


       Host database
             HostName <real IP address or hostname here>
             User username

Ex:

Host Server
      HostName 192.168.1.22
      User lakshman


ssh Server