Category: GNU/Linux Bash

Everything about the GNU/Linux Bash.

Backtrack How to

This is an collection of problems and bugs I had with Backtrack 5 R2 (Linux based Distribution).

To download Backtrack look at http://www.backtrack-linux.org/downloads/

 

Ubuntu software centre and update manager

For more Software, I installed the ubuntu software centre with this command:

sudo apt-get install software-center

then run a update:

sudo apt-get update && apt-get dist-upgrade

now you could choose your software sources at:

System > Administration > Software Sources

If you want the Update manager, run this:

sudo apt-get install update-manager

Or you could add the ubuntu repository to your system, just open the “/etc/apt/sources.list” file and generate a list from http://repogen.simplylinux.ch/generate.php, now you could add what you want.

 

NVIDIA or ATI/AMD driver

NVIDIA: http://www.nvidia.de/Download/indexsg.aspx?lang=de

just run it from your download folder.

ATI/AMD: http://support.amd.com/us/gpudownload/Pages/index.aspx 

Code:

sudo sh amd-driver.run --buildpkg Ubuntu/lucid
sudo dpkg -i fglrx*.deb
sudo aticonfig --initial -f

After a reboot you could check your driver status with:

fglrxinfo

 

Network

If you need more features at your network just install what you need:

network-manager-openvpn – network management framework (OpenVPN plugin core)
network-manager-openvpn-gnome – Network Management framework (OpenVPN plugin GNOME GUI)
network-manager-pptp – network management framework (PPTP plugin)
network-manager-pptp-gnome – network management framework (PPTP plugin)
network-manager-vpnc – network management framework (VPNC plugin core)
network-manager-vpnc-gnome – network management framework (VPNC plugin GNOME GUI)
network-manager – network management framework daemon
network-manager-dev – network management framework (development files)
network-manager-gnome – network management framework (GNOME frontend)

sudo apt-get install network-manager-openvpn
sudo apt-get install network-manager-openvpn-gnome
sudo apt-get install network-manager-pptp
sudo apt-get install network-manager-pptp-gnome
sudo apt-get install network-manager-vpnc
sudo apt-get install network-manager-vpnc-gnome
sudo apt-get install network-manager
sudo apt-get install network-manager-dev
sudo apt-get install network-manager-gnome

 

Add the Network icon to the panel:

echo auto lo > /etc/network/interfaces
echo iface lo inet loopback >> /etc/network/interfaces
service network-manager start
nm-applet &

 

network is blocked

To solved this run this:

sudo rfkill unblock all

 

Disable bell in terminal

open the file “/etc/inputrc” and add this:

set bell-style none

 

Mint backup

run this:

sudo add-apt-repository ppa:webupd8team/mintbackup && sudo apt-get update
sudo apt-get install mintbackup

 

BUG : wait for sound system to respond

System > Preferences > Startup Applications add this:

/usr/bin/pulseaudio

 

BUG : Couldn’t execute command: xscreensaver-command -lock

run this command:

apt-get install xlockmore gconf-editor

System > Preferences > Keyboard Shortcuts
Lock Screen disable.
Add new “Ctrl+Alt+L” with “xlock” ,apply done!

 

BUG : Chrome wont start as root

Menue>Internet>Chrome>Properties>Comand and add this:

/usr/bin/chromium-browser %U --user-data-dir www.google.at

 

BUG : run a *.deb

sudo dpkg -i name.deb

 

BUG : E: Dynamic MMap ran out of room. Please increase the size of APT::Cache-Limit. Current value: 25165824. (man 5 apt.conf)

Solution A:

open “/etc/apt/apt.conf.d/70debconf” and add this:

APT::Cache-Limit "100000000";

then run this:

sudo apt-get clean && sudo apt-get update --fix-missing

Solution B:

open “/etc/apt/apt.conf.d/90user” and add this:

APT::Cache-Limit "100000000";

 

BUG : GRUB2 error: out of disk

sudo mount /dev/sda1 /mnt
sudo grub-install --root-directory=/mnt /dev/sda

 

BUG : VLC is not supposed to be run as root. Sorry.

sudo apt-get install ghex
ghex2 /usr/bin/vlc

In line 7F8, replace “geteuid” with “getppid”.

Benchmark Bash fastest replace with tr sed awk perl

Test String (10xX):

___XXXXX_____XXXXX_____

Test Cases Results must look like:

single char remove:

___XXXX_____XXXXX_____

single char replace:

___0XXXX_____XXXXX_____

string/multi char remove:

_____________

string/multi char replace:

___00000_____00000_____

Times:

run the test string from file 100000 times.

single char remove single char replace multi char remove multi char replace string remove string replace
sed 5.658s 5.774s 3.449s 5.929s 3.476s 5.724s
perl regex 5.604s 5.918s 3.428s 6.027s 3.482s 5.870s
awk gsub 3.469s 5.892s 3.339s 5.942s
tr bash 5.972s 5.897s
perl tr  5.996s  5.837s

 

For bash its the easiest way to use sed because its simpler to use perl and it could do the most things or if you do simple things you could use tr.In perl you could see this benchmark.

SED 4.2.2

single char remove:

time cat bench.txt | sed 's/X//'

single char replace:

time cat bench.txt | sed 's/X/0/'

multi char remove:

time cat bench.txt | sed 's/X//g'

multi char replace:

time cat bench.txt | sed 's/X/0/g'

string remove:

time cat bench.txt | sed 's/XXXXX//g'

string replace:

time cat bench.txt | sed 's/XXXXX/00000/g'

 

AWK 4.0.1

single replace with regex not possible.

multi char remove:

time cat bench.txt | awk '{gsub("X","",$1);print $1;}'

multi char replace:

time cat bench.txt | awk '{gsub("X","0",$1);print $1;}'

string remove:

time cat bench.txt | awk '{gsub("XXXXX","",$1);print $1;}'

string replace:

time cat bench.txt | awk '{gsub("XXXXX","00000",$1);print $1;}'

 

TR 8.21

single replace and remove not possible.

multi char replace:

time cat bench.txt | tr "X" "0"

string replace:

time cat bench.txt | tr "XXXXX" "00000"

 

PERL REGEX 5

single char remove:

time cat bench.txt | perl -lpe 's/X//'

single char replace:

time cat bench.txt | perl -lpe 's/X/0/'

multi char remove:

time cat bench.txt | perl -lpe 's/X//g'

multi char replace:

time cat bench.txt | perl -lpe 's/X/0/g'

string remove:

time cat bench.txt | perl -lpe 's/XXXXX//g'

string replace:

time cat bench.txt | perl -lpe 's/XXXXX/00000/g'

 

PERL TR 5

multi char replace:

time cat bench.txt | perl -lpe 's/X/0/g'

string replace:

time cat bench.txt | perl -lpe 's/XXXXX/00000/g'