Contents
Setup RDP for Ubuntu
User Management
CLI Useful Commands
Change terminal colors
Ubuntu netboot Images
Enable/Add partner repo
Get hostname via nslookup
SCP Commands
Zip using tar
Terminal access via web
Remove tab and trailing white spaces from file
Display permissions in numbers
Replace whitespaces in filenames
Go to specific line number via nano

CLI Useful Commands

Lazy unmount

umount -l mountpoint

Install qt

apt-get install libqt4-core libqt4-gui libqt4-dev pkg-config

Install ncurse in ubuntu

sudo apt-get install ncurses-dev

Create symbolic link

ln -s /source /destination

Remove symbolic link

rm /path to symbolic link

Find file(s)

find / "filename" -print

Check OS version

lsb_release -a

cat /etc/lsb-release

Local backup using rsync:

sudo rsync -azvv /path/to/source /path/to/destination

Remote backup using rsync:

sudo rsync --delete -axvv -e ssh remoteuser@remotehost:/path/to/remote/source /local/folder

An explanation of above options to commands:

--delete deletes files that don't exist on the system being backed up.(Optional)
-a preserves the date and times, and permissions of the files (same as -rlptgoD).
With this option rsync will: Descend recursively into all directories (-r),
copy symlinks as symlinks (-l),
preserve file permissions (-p),
preserve modification times (-t),
preserve groups (-g),
preserve file ownership (-o), and
preserve devices as devices (-D).
-z compresses the data
-vv increases the verbosity of the reporting process
-e specifies remote shell to use

Folder1 and 2 are place holders for the directories to be synchronized. Folder1 is the original folder, and 2 is the new folder, or existing one to be brought in sync with the first. Replace them with the folders you'd like. A / was added after folder1 so that only the contents, rather than whole folder, would be moved into the second folder. Set hardware clock to system clocke

hwclock --systohc

List running process

lsof

Monitor logs in console

tail -f /var/log/syslog

Install light light weight GUI to Ubuntu server

sudo apt-get install xubuntu-desktop

You can go even light excluding desktop addons like Evolution and OpenOffice etc.

sudo apt-get install --no-install-recommends xubuntu-desktop

Reset phpmyadmin session

rm /var/lib/php5/*

Install replace package

sudo apt-get install rpl

Replace val1 with val2

sudo rpl 'val1' 'val2' /temp/test.sh

Fix read only issue when in recovery mode, run the following command to make it writable

mount -o remount,rw /
mount -a

Check dhcp configuration and print out the errors if any

dhcpd -t

Set up static IP address, change addresses according to your setup

iface eth0 inet static
        address 192.168.5.5
        netmask 255.255.255.0
        network 192.168.5.0
        broadcast 192.168.5.255
        gateway 192.168.5.1
        # dns-* options are implemented by the resolvconf package, if installed
        dns-nameservers 192.168.5.1
        dns-search testlab.nt

Autologon Ubuntu Desktop

cat << EOT >> /etc/lightdm/lightdm.conf

# Auto login
[SeatDefaults]
greeter-session=unity-greeter
user-session=xfce4-session
autologin-user=rkhan
autologin-user-timeout=0
EOT

Autologon Ubuntu server

cat << EOT >> /etc/init/tty1.conf

#Auto loing
exec /bin/login -f USERNAME < /dev/tty1 > /dev/tty1 2>&1
EOT

echo "exec /bin/login -f USERNAME < /dev/tty1 > /dev/tty1 2>&1" >> /etc/init/tty1.conf

Usefull trafic monitoring tools bmon, slurm, tcptrack, iftop

apt-get install tcptrack

Disable crtl+alt+delete

/etc/init/control-alt-delete.conf

and comment

#exec shutdown -r now "Control-Alt-Delete pressed"

Allow user to reboot system

chmod +s /sbin/reboot

Archive using tar

backup /mybackup direcoty (adjust the directory)

tar -pczvf mybackup.tar.gz /mybackup

backup /mybackup direcoty (adjust the directory) with current time stamp

tar -pczf mybackup-$(date +%m%d%y).tar.gz /mybackup

extract from tar archive

tar -zxvf mybackup.tar.gz

Find the side of file/folder in linux

du -ch file/folder | grep total

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Ubuntu RDP

install packages

apt-get install xrdp; sudo apt-get install xfce4

setup session

echo "xfce4-session" > ~/.xsession

restart service

service xrdp restart

try it from windows machine, make sure to replace the ipaddress with the ip address of ubuntu machine you are connecting to

mstsc /v:ipaddress

Reference
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User Management

Add a new user to existing secondary group, create new user rkhan and add him to abc existing group

useradd -G abc rkhan

Setup password for user rkhan

passwd rkhan

Add existing user to multiple group

useradd -G admins,ftp,www,abc rkhan

get the id of rkhan

id rkhan

Add a existing user to existing group

usermod -a -G abc rkhan

change primary group of rkhan to abc

usermod -g abc rkhan

Remove user from group, rkhan from abc group

deluser rkhan abc

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Change terminal colors

command to set color

setterm -background white -foreground black -store

colors

0 = black
1 = blue
2 = green
3 = cyan
4 = red
5 = purple
6 = brown/yellow
7 = white

http://www.tuxradar.com/answers/482
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Ubuntu netboot Image

Ubuntu 18.04 LTS (32 bit)

wget http://archive.ubuntu.com/ubuntu/dists/bionic/main/installer-i386/current/images/netboot/ubuntu-installer/i386/initrd.gz
wget http://archive.ubuntu.com/ubuntu/dists/bionic/main/installer-i386/current/images/netboot/ubuntu-installer/i386/linux

Ubuntu 18.04 LTS (64 bit)

wget http://archive.ubuntu.com/ubuntu/dists/bionic/main/installer-amd64/current/images/netboot/ubuntu-installer/amd64/initrd.gz
wget http://archive.ubuntu.com/ubuntu/dists/bionic/main/installer-amd64/current/images/netboot/ubuntu-installer/amd64/linux

Ubuntu 12.04 LTS (32 bit)

wget http://archive.ubuntu.com/ubuntu/dists/precise-updates/main/installer-i386/current/images/netboot/ubuntu-installer/i386/initrd.gz
wget http://archive.ubuntu.com/ubuntu/dists/precise-updates/main/installer-i386/current/images/netboot/ubuntu-installer/i386/linux

Ubuntu 12.04 LTS (64 bit)

wget http://archive.ubuntu.com/ubuntu/dists/precise-updates/main/installer-amd64/current/images/netboot/ubuntu-installer/amd64/initrd.gz
wget http://archive.ubuntu.com/ubuntu/dists/precise-updates/main/installer-amd64/current/images/netboot/ubuntu-installer/amd64/linux

Ubuntu 14.04 LTS (32 bit)

wget http://archive.ubuntu.com/ubuntu/dists/trusty-updates/main/installer-i386/current/images/netboot/ubuntu-installer/i386/initrd.gz
wget http://archive.ubuntu.com/ubuntu/dists/trusty-updates/main/installer-i386/current/images/netboot/ubuntu-installer/i386/linux

Ubuntu 14.04 LTS (64 bit)

wget http://archive.ubuntu.com/ubuntu/dists/trusty-updates/main/installer-amd64/current/images/netboot/ubuntu-installer/amd64/initrd.gz
wget http://archive.ubuntu.com/ubuntu/dists/trusty-updates/main/installer-amd64/current/images/netboot/ubuntu-installer/amd64/linux

Ubuntu 16.04 LTS (32 bit)

wget http://archive.ubuntu.com/ubuntu/dists/xenial-updates/main/installer-i386/current/images/netboot/ubuntu-installer/i386/initrd.gz
wget http://archive.ubuntu.com/ubuntu/dists/xenial-updates/main/installer-i386/current/images/netboot/ubuntu-installer/i386/linux

Ubuntu 16.04 LTS (64 bit)

wget http://archive.ubuntu.com/ubuntu/dists/xenial-updates/main/installer-amd64/current/images/netboot/ubuntu-installer/amd64/initrd.gz
wget http://archive.ubuntu.com/ubuntu/dists/xenial-updates/main/installer-amd64/current/images/netboot/ubuntu-installer/amd64/linux

reference
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Enable partner repo

add-apt-repository "deb http://archive.canonical.com/ $(lsb_release -sc) partner"

reference
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Get hostname via nslookup and set for current session

if=`ls /sys/class/net`
nic=`echo $if | awk '{print $1}'`
ip=`ifconfig $nic | grep 'inet addr' | cut -d ':' -f2 | awk '{print $1}'`
name=`nslookup $ip | awk '{print $4}' | cut -d '.' -f1`
/bin/hostname $name

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SCP Commands

Copy the file text.txt from a remote host to the local host (root directory, adjust the directory)

scp username@remotehost:/text.txt /

Copy the file test.txt from the local host to a remote host

scp test.txt username@remotehost.edu:/test.txt

Copy the directory test from the local host to a remote host's root directory (adjust the directory)

scp -r test username@remotehost.edu:/

Copy the file test.txt from remote host host1 to remote host2

scp username@host1:/test.txt \
username@host2:/

Copying the files test.txt and abc.txt from the local host to your home directory on the remote host

scp test.txt abc.txt username@remotehost.edu:~

Copy the file test.txt from the local host to a remote host using port 2264

scp -P 2264 test.txt username@remotehost.edu:/

Copy multiple files from the remote host to your current directory on the local host

scp your_username@remotehost.edu:/some/remote/directory/\{a,b,c\} .
scp your_username@remotehost.edu:~/\{foo.txt,bar.txt\} .

By default scp uses the Triple-DES cipher to encrypt the data being sent. Using the Blowfish cipher has been shown to increase speed. This can be done by using option -c blowfish in the command line.

scp -c blowfish some_file your_username@remotehost.edu:~

It is often suggested that the -C option for compression should also be used to increase speed. The effect of compression, however, will only significantly increase speed if your connection is very slow. Otherwise it may just be adding extra burden to the CPU. An example of using blowfish and compression:

scp -c blowfish -C local_file your_username@remotehost.edu:~

reference
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Terminal access via web

install package

sudo apt-cache search shellinabox; apt-get install openssl shellinabox

configure port (optional)

sed -i 's/SHELLINABOX_PORT=4200/SHELLINABOX_PORT=8022/g' /etc/default/shellinabox
sed -i 's/SHELLINABOX_ARGS="--no-beep"/SHELLINABOX_ARGS="--no-beep -s /:SSH:localhost"/g' /etc/default/shellinabox

restart service

sudo invoke-rc.d shellinabox restart

reference 1
reference 2
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Remove tab and trailing white spaces from file

remove indented tabs

sed -i 's/^[ \t]*//' advan.cfg

remove trailing white spaces

sed -i 's/[[:space:]]*$//' advan.cfg

ref # 1 ref # 2

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Display permissions in numbers

for files

stat -c "%a %n" file

for folder

stat -c "%a %n" folder

reference
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Remove whitespaces in filenames

for folders

find -name "* *" -type d | rename 's/ /_/g'    # do the directories first

for files

find -name "* *" -type f | rename 's/ /_/g'

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Go to specific line number via nano

nano +107 filename

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