Thursday, 17 October 2013

10 Ways to Hack a Facebook Account

Facebook is one of the most widely used social networking site with more than 750 million users, as a reason if which it has become the number 1 target of hackers have , I have written a couple of post related to facebook hacking here. I mentioned the top methods which were used by hackers to hack facebook accounts, however lots of things have changed in 2013, Lots of methods have went outdated or have been patched up by facebook and lots of new methods have been introduced, So in this post I will write the top 10 methods how hackers can hack facebook accounts.

10 Ways How Hackers Can Hack Facebook Accounts?

So here are the top 10 methods which have been the most popular in 2012:

1. Session Hijacking?

Session Hijacking can be often very dangerous if you are accessing Facebook on a http:// connection, In a Session Hijacking attack a hacker steals the victims browser cookie which is used to authenticate a user on a website and uses to it to access victims account, Session hijacking is widely used on Lan’s.

2. Sidejacking With Firesheep?

Sidejacking attack went common in late 2010, however it’s still popular now a days, Firesheep is widely used to carry out sidejacking attacks, Firesheep only works when the attacker and victim is on the same wifi network. A sidejacking attack is basically another name for http session hijacking, but it’s more targeted towards wifi users.

3. Mobile Phone Hacking ?

Millions of Facebook users access Facebook through their mobile phones. In case the hacker can gain access to the victims mobile phone then he can probably gain access to his/her Facebook account. Their are lots of Mobile Spying softwares used to monitor a Cellphone.

4. DNS Spoofing?

If both the victim and attacker are on the same network, an attacker can use a DNS spoofing attack and change the original page to his own fake page and hence can get access to victims facebook account.

5. USB Hacking?

If an attacker has physical access to your computer, he could just insert a USB programmed with a function to automatically extract saved passwords in the browser.

6. Man In the Middle Attacks?

If the victim and attacker are on the same lan and on a switch based network, A hacker can place himself b/w the client and the server or he could also act as a default gateway and hence capturing all the traffic in between, ARP Poisoning which is the other name for man in the middle attacks is a very broad topic and is beyond the scope of this article.

7. Botnets? 

Botnets are not commonly used for hacking facebook accounts, because of it’s high setup costs, They are used to carry more advanced attacks, A botnet is basically a collection of compromised computer, The infection process is same as the keylogging, however a botnet gives you, additional options in for carrying out attacks with the compromised computer. Some of the most popular botnets include Spyeye and Zeus.

8. Stealers?

Almost 80% percent people use stored passwords in their browser to access the facebook, This is is quite convenient but can sometimes be extremely dangerous, Stealers are software’s specially designed to capture the saved passwords stored in the victims browser, Stealers once FUD can be extremely powerful.

9. Facebook Phishing?

Phishing still is the most popular attack vector used for hacking facebook accounts, There are variety of methods to carry out phishing attack, In a simple phishing attacks a hacker creates a fake login page which exactly looks like the real facebook page and then asks the victim to login into that page, Once the victim logins through the fake page the victims “Email Address” and “Password” is stored in to a text file, The hacker then downloads the text file and get’s his hands on the victims credentials.


Keylogging, according to me is the easiest way to hack a facebook password.
NOTE: Guys if u have any queries just comment them below.

Monday, 14 October 2013

Keyboard Lights Dancing

How to make your Keyboard lights dancing(blinking)?

1.Open Notepad in your computer.

2.Copy the below code in to your notepad.

Set wshShell =wscript.CreateObject("WScript.Shell")
 wscript.sleep 100
 wshshell.sendkeys "{CAPSLOCK}"
 wshshell.sendkeys "{NUMLOCK}"
 wshshell.sendkeys "{SCROLLLOCK}"

3.Copy the above code in to your Notepad and save it with extension as(example:anything.vbs) .vbs the file on your desktop or at your specified location then a new file would be created with the name with which you saved the file.

5.Just open the file by double clicking the file which has been created.

6.You are done your keyboard lights starts blinking.

How to disable Blinking Led ?

       1. First open Task manager [ctrl+alt+del ]
       2. Then Go to process tab.
       3. Select wscript.exe
       4. Click on End process.

Thursday, 26 September 2013

Windows CMD Command Line

   ADDUSERS Add or list users to/from a CSV file
   ADmodcmd Active Directory Bulk Modify
   ARP      Address Resolution Protocol
   ASSOC    Change file extension associations•
   ASSOCIAT One step file association
   ATTRIB   Change file attributes
   BCDBOOT  Create or repair a system partition
   BITSADMIN Background Intelligent Transfer Service
   BOOTCFG  Edit Windows boot settings
   BROWSTAT Get domain, browser and PDC info
   CACLS    Change file permissions
   CALL     Call one batch program from another•
   CD       Change Directory - move to a specific Folder•
   CHANGE   Change Terminal Server Session properties
   CHKDSK   Check Disk - check and repair disk problems
   CHKNTFS  Check the NTFS file system
   CHOICE   Accept keyboard input to a batch file
   CIPHER   Encrypt or Decrypt files/folders
   CleanMgr Automated cleanup of Temp files, recycle bin
   CLEARMEM Clear memory leaks
   CLIP     Copy STDIN to the Windows clipboard
   CLS      Clear the screen•
   CLUSTER  Windows Clustering
   CMD      Start a new CMD shell
   CMDKEY   Manage stored usernames/passwords
   COLOR    Change colors of the CMD window•
   COMP     Compare the contents of two files or sets of files
   COMPACT  Compress files or folders on an NTFS partition
   COMPRESS Compress individual files on an NTFS partition
   CON2PRT  Connect or disconnect a Printer
   CONVERT  Convert a FAT drive to NTFS
   COPY     Copy one or more files to another location•
   CSCcmd   Client-side caching (Offline Files)
   CSVDE    Import or Export Active Directory data 
   DATE     Display or set the date•
   DEFRAG   Defragment hard drive
   DEL      Delete one or more files•
   DELPROF  Delete user profiles
   DELTREE  Delete a folder and all subfolders
   DevCon   Device Manager Command Line Utility 
   DIR      Display a list of files and folders•
   DIRUSE   Display disk usage
   DISKPART Disk Administration
   DISKSHADOW Volume Shadow Copy Service
   DNSSTAT  DNS Statistics
   DOSKEY   Edit command line, recall commands, and create macros
   DriverQuery Display installed device drivers
   DSACLs   Active Directory ACLs
   DSAdd    Add items to active directory (user group computer) 
   DSGet    View items in active directory (user group computer)
   DSQuery  Search for items in active directory (user group computer)
   DSMod    Modify items in active directory (user group computer)
   DSMove   Move an Active directory Object
   DSRM     Remove items from Active Directory
   ECHO     Display message on screen•
   ENDLOCAL End localisation of environment changes in a batch file•
   ERASE    Delete one or more files•
   EVENTCREATE Add a message to the Windows event log
   EXIT     Quit the current script/routine and set an errorlevel•
   EXPAND   Uncompress files
   EXTRACT  Uncompress CAB files
   FC       Compare two files
   FIND     Search for a text string in a file
   FINDSTR  Search for strings in files
   FOR /F   Loop command: against a set of files•
   FOR /F   Loop command: against the results of another command•
   FOR      Loop command: all options Files, Directory, List•
   FORFILES Batch process multiple files
   FORMAT   Format a disk
   FREEDISK Check free disk space (in bytes)
   FSUTIL   File and Volume utilities
   FTP      File Transfer Protocol
   FTYPE    File extension file type associations•
   GETMAC   Display the Media Access Control (MAC) address
   GLOBAL   Display membership of global groups
   GOTO     Direct a batch program to jump to a labelled line•
   GPRESULT Display Resultant Set of Policy information
   GPUPDATE Update Group Policy settings
   HELP     Online Help
   iCACLS   Change file and folder permissions
   IF       Conditionally perform a command•
   IFMEMBER Is the current user a member of a Workgroup
   IPCONFIG Configure IP
   KILL     Remove a program from memory
   LABEL    Edit a disk label
   LOCAL    Display membership of local groups
   LOGEVENT Write text to the event viewer
   LOGMAN   Manage Performance Monitor
   LOGOFF   Log a user off
   LOGTIME  Log the date and time in a file
   MAPISEND Send email from the command line
   MBSAcli  Baseline Security Analyzer
   MEM      Display memory usage
   MD       Create new folders•
   MKLINK   Create a symbolic link (linkd)
   MODE     Configure a system device
   MORE     Display output, one screen at a time
   MOUNTVOL Manage a volume mount point
   MOVE     Move files from one folder to another•
   MOVEUSER Move a user from one domain to another
   MSG      Send a message
   MSIEXEC  Microsoft Windows Installer
   MSINFO32 System Information
   MSTSC    Terminal Server Connection (Remote Desktop Protocol)
   MV       Copy in-use files
   NET      Manage network resources
   NETDOM   Domain Manager
   NETSH    Configure Network Interfaces, Windows Firewall & Remote access
   NETSVC   Command-line Service Controller
   NBTSTAT  Display networking statistics (NetBIOS over TCP/IP)
   NETSTAT  Display networking statistics (TCP/IP)
   NOW      Display the current Date and Time 
   NSLOOKUP Name server lookup
   NTBACKUP Backup folders to tape
   NTRIGHTS Edit user account rights
   OPENFILES Query or display open files
   PATH     Display or set a search path for executable files•
   PATHPING Trace route plus network latency and packet loss
   PAUSE    Suspend processing of a batch file and display a message•
   PERMS    Show permissions for a user
   PERFMON  Performance Monitor
   PING     Test a network connection
   POPD     Return to a previous directory saved by PUSHD•
   PORTQRY  Display the status of ports and services
   POWERCFG Configure power settings
   PRINT    Print a text file
   PRINTBRM Print queue Backup/Recovery
   PRNCNFG  Display, configure or rename a printer
   PRNMNGR  Add, delete, list printers set the default printer
   PROMPT   Change the command prompt•
   PsExec     Execute process remotely
   PsFile     Show files opened remotely
   PsGetSid   Display the SID of a computer or a user
   PsInfo     List information about a system
   PsKill     Kill processes by name or process ID
   PsList     List detailed information about processes
   PsLoggedOn Who's logged on (locally or via resource sharing)
   PsLogList  Event log records
   PsPasswd   Change account password
   PsService  View and control services
   PsShutdown Shutdown or reboot a computer
   PsSuspend  Suspend processes
   PUSHD    Save and then change the current directory•
   QGREP    Search file(s) for lines that match a given pattern
   Query Process    Display processes (TS/Remote Desktop)
   Query Session    Display all sessions (TS/Remote Desktop)
   Query TermServer List all servers (TS/Remote Desktop)
   Query User       Display user sessions (TS/Remote Desktop)
   RASDIAL  Manage RAS connections
   RASPHONE Manage RAS connections
   RECOVER  Recover a damaged file from a defective disk
   REG      Registry: Read, Set, Export, Delete keys and values
   REGEDIT  Import or export registry settings
   REGSVR32 Register or unregister a DLL
   REGINI   Change Registry Permissions
   REM      Record comments (remarks) in a batch file•
   REN      Rename a file or files•
   REPLACE  Replace or update one file with another
   Reset Session  Delete a Remote Desktop Session
   RD       Delete folder(s)•
   RMTSHARE Share a folder or a printer
   ROBOCOPY Robust File and Folder Copy
   ROUTE    Manipulate network routing tables
   RUN      Start | RUN commands
   RUNAS    Execute a program under a different user account
   RUNDLL32 Run a DLL command (add/remove print connections)

   SC       Service Control
   SCHTASKS Schedule a command to run at a specific time
   SCLIST   Display Services
   SET      Display, set, or remove session environment variables•
   SETLOCAL Control the visibility of environment variables•
   SETX     Set environment variables
   SFC      System File Checker 
   SHARE    List or edit a file share or print share
   ShellRunAs Run a command under a different user account
   SHIFT    Shift the position of batch file parameters•
   SHORTCUT Create a windows shortcut (.LNK file)
   SHOWGRPS List the Workgroups a user has joined
   SHOWMBRS List the Users who are members of a Workgroup
   SHUTDOWN Shutdown the computer
   SLEEP    Wait for x seconds
   SLMGR    Software Licensing Management (Vista/2008)
   SOON     Schedule a command to run in the near future
   SORT     Sort input
   START    Start a program, command or batch file•
   SU       Switch User
   SUBINACL Edit file and folder Permissions, Ownership and Domain
   SUBST    Associate a path with a drive letter
   SYSTEMINFO List system configuration
   TAKEOWN  Take ownership of a file
   TASKLIST List running applications and services
   TASKKILL Remove a running process from memory
   TIME     Display or set the system time•
   TIMEOUT  Delay processing of a batch file
   TITLE    Set the window title for a CMD.EXE session•
   TLIST    Task list with full path
   TOUCH    Change file timestamps    
   TRACERT  Trace route to a remote host
   TREE     Graphical display of folder structure
   TSSHUTDN Remotely shut down or reboot a terminal server
   TYPE     Display the contents of a text file•
   TypePerf Write performance data to a log file
   USRSTAT  List domain usernames and last login
   VER      Display version information•
   VERIFY   Verify that files have been saved•
   VOL      Display a disk label•
   WAITFOR  Wait for or send a signal
   WHERE    Locate and display files in a directory tree
   WHOAMI   Output the current UserName and domain
   WINDIFF  Compare the contents of two files or sets of files
   WINMSDP  Windows system report
   WINRM    Windows Remote Management
   WINRS    Windows Remote Shell
   WMIC     WMI Commands
   WUAUCLT  Windows Update
   XCACLS   Change file and folder permissions
   XCOPY    Copy files and folders

50 Most Frequently Used UNIX / Linux Commands

1. tar command examples

Create a new tar archive.

$ tar cvf archive_name.tar dirname/

Extract from an existing tar archive.

$ tar xvf archive_name.tar

View an existing tar archive.

$ tar tvf archive_name.tar

More tar examples: The Ultimate Tar Command Tutorial with 10 Practical Examples

2. grep command examples

Search for a given string in a file (case in-sensitive search).

$ grep -i "the" demo_file

Print the matched line, along with the 3 lines after it.

$ grep -A 3 -i "example" demo_text

Search for a given string in all files recursively

$ grep -r "ramesh" *

More grep examples: Get a Grip on the Grep! – 15 Practical Grep Command Examples

3. find command examples

Find files using file-name ( case in-sensitve find)

# find -iname "MyCProgram.c"

Execute commands on files found by the find command

$ find -iname "MyCProgram.c" -exec md5sum {} \;

Find all empty files in home directory

# find ~ -empty

More find examples: Mommy, I found it! — 15 Practical Linux Find Command Examples

4. ssh command examples
Login to remote host

ssh -l jsmith

Debug ssh client

ssh -v -l jsmith

Display ssh client version

$ ssh -V
OpenSSH_3.9p1, OpenSSL 0.9.7a Feb 19 2003

More ssh examples: 5 Basic Linux SSH Client Commands

5. sed command examples
When you copy a DOS file to Unix, you could find \r\n in the end of each line. This example converts the DOS file format to Unix file format using sed command.

$sed 's/.$//' filename

Print file content in reverse order

$ sed -n '1!G;h;$p' thegeekstuff.txt

Add line number for all non-empty-lines in a file

$ sed '/./=' thegeekstuff.txt | sed 'N; s/\n/ /'

More sed examples: Advanced Sed Substitution Examples

6. awk command examples
Remove duplicate lines using awk

$ awk '!($0 in array) { array[$0]; print }' temp

Print all lines from /etc/passwd that has the same uid and gid

$awk -F ':' '$3==$4' passwd.txt

Print only specific field from a file.

$ awk '{print $2,$5;}' employee.txt

More awk examples: 8 Powerful Awk Built-in Variables – FS, OFS, RS, ORS, NR, NF, FILENAME, FNR

7. vim command examples
Go to the 143rd line of file

$ vim +143 filename.txt

Go to the first match of the specified

$ vim +/search-term filename.txt

Open the file in read only mode.

$ vim -R /etc/passwd

More vim examples: How To Record and Play in Vim Editor

8. diff command examples
Ignore white space while comparing.

# diff -w name_list.txt name_list_new.txt

< John Doe --- > John M Doe
> Jason Bourne

More diff examples: Top 4 File Difference Tools on UNIX / Linux – Diff, Colordiff, Wdiff, Vimdiff

9. sort command examples
Sort a file in ascending order

$ sort names.txt

Sort a file in descending order

$ sort -r names.txt

Sort passwd file by 3rd field.

$ sort -t: -k 3n /etc/passwd | more

10. export command examples
To view oracle related environment variables.

$ export | grep ORACLE
declare -x ORACLE_BASE="/u01/app/oracle"
declare -x ORACLE_HOME="/u01/app/oracle/product/10.2.0"
declare -x ORACLE_SID="med"
declare -x ORACLE_TERM="xterm"

To export an environment variable:

$ export ORACLE_HOME=/u01/app/oracle/product/10.2.0

11. xargs command examples
Copy all images to external hard-drive

# ls *.jpg | xargs -n1 -i cp {} /external-hard-drive/directory

Search all jpg images in the system and archive it.

# find / -name *.jpg -type f -print | xargs tar -cvzf images.tar.gz

Download all the URLs mentioned in the url-list.txt file

# cat url-list.txt | xargs wget –c

12. ls command examples

Display filesize in human readable format (e.g. KB, MB etc.,)

$ ls -lh
-rw-r----- 1 ramesh team-dev 8.9M Jun 12 15:27 arch-linux.txt.gz

Order Files Based on Last Modified Time (In Reverse Order) Using ls -ltr

$ ls -ltr

Visual Classification of Files With Special Characters Using ls -F

$ ls -F

More ls examples: Unix LS Command: 15 Practical Examples

13. pwd command
pwd is Print working directory. What else can be said about the good old pwd who has been printing the current directory name for ages.

14. cd command examples
Use “cd -” to toggle between the last two directories

Use “shopt -s cdspell” to automatically correct mistyped directory names on cd

More cd examples: 6 Awesome Linux cd command Hacks

15. gzip command examples

To create a *.gz compressed file:

$ gzip test.txt

To uncompress a *.gz file:

$ gzip -d test.txt.gz

Display compression ratio of the compressed file using gzip -l

$ gzip -l *.gz
         compressed        uncompressed  ratio uncompressed_name
              23709               97975  75.8% asp-patch-rpms.txt

16. bzip2 command examples
To create a *.bz2 compressed file:

$ bzip2 test.txt

To uncompress a *.bz2 file:

bzip2 -d test.txt.bz2

More bzip2 examples: BZ is Eazy! bzip2, bzgrep, bzcmp, bzdiff, bzcat, bzless, bzmore examples

17. unzip command examples
To extract a *.zip compressed file:

$ unzip

View the contents of *.zip file (Without unzipping it):

$ unzip -l
  Length     Date   Time    Name
 --------    ----   ----    ----
    40995  11-30-98 23:50   META-INF/MANIFEST.MF
    32169  08-25-98 21:07   classes_
    15964  08-25-98 21:07   classes_names
    10542  08-25-98 21:07   classes_ncomp

18. shutdown command examples
Shutdown the system and turn the power off immediately.

# shutdown -h now

Shutdown the system after 10 minutes.

# shutdown -h +10

Reboot the system using shutdown command.

# shutdown -r now

Force the filesystem check during reboot.

# shutdown -Fr now

19. ftp command examples
Both ftp and secure ftp (sftp) has similar commands. To connect to a remote server and download multiple files, do the following.

$ ftp IP/hostname
ftp> mget *.html

To view the file names located on the remote server before downloading, mls ftp command as shown below.

ftp> mls *.html -

More ftp examples: FTP and SFTP Beginners Guide with 10 Examples

20. crontab command examples
View crontab entry for a specific user

# crontab -u john -l

Schedule a cron job every 10 minutes.

*/10 * * * * /home/ramesh/check-disk-space

More crontab examples: Linux Crontab: 15 Awesome Cron Job Examples

21. service command examples
Service command is used to run the system V init scripts. i.e Instead of calling the scripts located in the /etc/init.d/ directory with their full path, you can use the service command.

Check the status of a service:

# service ssh status

Check the steatus of all the services.

service --status-all

Restart a service.

# service ssh restart

22. ps command examples
ps command is used to display information about the processes that are running in the system.

While there are lot of arguments that could be passed to a ps command, following are some of the common ones.

To view current running processes.

$ ps -ef | more

To view current running processes in a tree structure. H option stands for process hierarchy.

$ ps -efH | more

23. free command examples
This command is used to display the free, used, swap memory available in the system.

Typical free command output. The output is displayed in bytes.

$ free
             total       used       free     shared    buffers     cached
Mem:       3566408    1580220    1986188          0     203988     902960
-/+ buffers/cache:     473272    3093136
Swap:      4000176          0    4000176

If you want to quickly check how many GB of RAM your system has use the -g option. -b option displays in bytes, -k in kilo bytes, -m in mega bytes.

$ free -g
             total       used       free     shared    buffers     cached
Mem:             3          1          1          0          0          0
-/+ buffers/cache:          0          2
Swap:            3          0          3

If you want to see a total memory ( including the swap), use the -t switch, which will display a total line as shown below.

ramesh@ramesh-laptop:~$ free -t
             total       used       free     shared    buffers     cached
Mem:       3566408    1592148    1974260          0     204260     912556
-/+ buffers/cache:     475332    3091076
Swap:      4000176          0    4000176
Total:     7566584    1592148    5974436

24. top command examples
top command displays the top processes in the system ( by default sorted by cpu usage ). To sort top output by any column, Press O (upper-case O) , which will display all the possible columns that you can sort by as shown below.

Current Sort Field:  P  for window 1:Def
Select sort field via field letter, type any other key to return

  a: PID        = Process Id              v: nDRT       = Dirty Pages count
  d: UID        = User Id                 y: WCHAN      = Sleeping in Function
  e: USER       = User Name               z: Flags      = Task Flags

To displays only the processes that belong to a particular user use -u option. The following will show only the top processes that belongs to oracle user.

$ top -u oracle

More top examples: Can You Top This? 15 Practical Linux Top Command Examples

25. df command examples
Displays the file system disk space usage. By default df -k displays output in bytes.

$ df -k
Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/sda1             29530400   3233104  24797232  12% /
/dev/sda2            120367992  50171596  64082060  44% /home

df -h displays output in human readable form. i.e size will be displayed in GB’s.

ramesh@ramesh-laptop:~$ df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda1              29G  3.1G   24G  12% /
/dev/sda2             115G   48G   62G  44% /home

Use -T option to display what type of file system.

ramesh@ramesh-laptop:~$ df -T
Filesystem    Type   1K-blocks      Used Available Use% Mounted on
/dev/sda1     ext4    29530400   3233120  24797216  12% /
/dev/sda2     ext4   120367992  50171596  64082060  44% /home

26. kill command examples
Use kill command to terminate a process. First get the process id using ps -ef command, then use kill -9 to kill the running Linux process as shown below. You can also use killall, pkill, xkill to terminate a unix process.

$ ps -ef | grep vim
ramesh    7243  7222  9 22:43 pts/2    00:00:00 vim

$ kill -9 7243

More kill examples: 4 Ways to Kill a Process – kill, killall, pkill, xkill

27. rm command examples
Get confirmation before removing the file.

$ rm -i filename.txt

It is very useful while giving shell metacharacters in the file name argument.

Print the filename and get confirmation before removing the file.

$ rm -i file*

Following example recursively removes all files and directories under the example directory. This also removes the example directory itself.

$ rm -r example

28. cp command examples

Copy file1 to file2 preserving the mode, ownership and timestamp.

$ cp -p file1 file2

Copy file1 to file2. if file2 exists prompt for confirmation before overwritting it.

$ cp -i file1 file2

29. mv command examples

Rename file1 to file2. if file2 exists prompt for confirmation before overwritting it.

$ mv -i file1 file2

Note: mv -f is just the opposite, which will overwrite file2 without prompting.

mv -v will print what is happening during file rename, which is useful while specifying shell metacharacters in the file name argument.

$ mv -v file1 file2

30. cat command examples

You can view multiple files at the same time. Following example prints the content of file1 followed by file2 to stdout.

$ cat file1 file2

While displaying the file, following cat -n command will prepend the line number to each line of the output.

$ cat -n /etc/logrotate.conf
    1    /var/log/btmp {
    2        missingok
    3        monthly
    4        create 0660 root utmp
    5        rotate 1
    6    }

31. mount command examples

To mount a file system, you should first create a directory and mount it as shown below.

# mkdir /u01

# mount /dev/sdb1 /u01

You can also add this to the fstab for automatic mounting. i.e Anytime system is restarted, the filesystem will be mounted.

/dev/sdb1 /u01 ext2 defaults 0 2

32. chmod command examples
chmod command is used to change the permissions for a file or directory.

Give full access to user and group (i.e read, write and execute ) on a specific file.

$ chmod ug+rwx file.txt

Revoke all access for the group (i.e read, write and execute ) on a specific file.

$ chmod g-rwx file.txt

Apply the file permissions recursively to all the files in the sub-directories.

$ chmod -R ug+rwx file.txt

More chmod examples: 7 Chmod Command Examples for Beginners

33. chown command examples
chown command is used to change the owner and group of a file. \

To change owner to oracle and group to db on a file. i.e Change both owner and group at the same time.

$ chown oracle:dba

Use -R to change the ownership recursively.

$ chown -R oracle:dba /home/oracle

34. passwd command examples
Change your password from command line using passwd. This will prompt for the old password followed by the new password.

$ passwd

Super user can use passwd command to reset others password. This will not prompt for current password of the user.

# passwd USERNAME

Remove password for a specific user. Root user can disable password for a specific user. Once the password is disabled, the user can login without entering the password.

# passwd -d USERNAME

35. mkdir command examples
Following example creates a directory called temp under your home directory.

$ mkdir ~/temp

Create nested directories using one mkdir command. If any of these directories exist already, it will not display any error. If any of these directories doesn’t exist, it will create them.

$ mkdir -p dir1/dir2/dir3/dir4/

36. ifconfig command examples
Use ifconfig command to view or configure a network interface on the Linux system.

View all the interfaces along with status.

$ ifconfig -a

Start or stop a specific interface using up and down command as shown below.

$ ifconfig eth0 up

$ ifconfig eth0 down

More ifconfig examples: Ifconfig: 7 Examples To Configure Network Interface

37. uname command examples
Uname command displays important information about the system such as — Kernel name, Host name, Kernel release number,
Processor type, etc.,

Sample uname output from a Ubuntu laptop is shown below.

$ uname -a
Linux john-laptop 2.6.32-24-generic #41-Ubuntu SMP Thu Aug 19 01:12:52 UTC 2010 i686 GNU/Linux

38. whereis command examples
When you want to find out where a specific Unix command exists (for example, where does ls command exists?), you can execute the following command.

$ whereis ls
ls: /bin/ls /usr/share/man/man1/ls.1.gz /usr/share/man/man1p/ls.1p.gz

When you want to search an executable from a path other than the whereis default path, you can use -B option and give path as argument to it. This searches for the executable lsmk in the /tmp directory, and displays it, if it is available.

$ whereis -u -B /tmp -f lsmk
lsmk: /tmp/lsmk

39. whatis command examples
Whatis command displays a single line description about a command.

$ whatis ls
ls        (1)  - list directory contents

$ whatis ifconfig
ifconfig (8)         - configure a network interface

40. locate command examples
Using locate command you can quickly search for the location of a specific file (or group of files). Locate command uses the database created by updatedb.

The example below shows all files in the system that contains the word crontab in it.

$ locate crontab

41. man command examples
Display the man page of a specific command.

$ man crontab

When a man page for a command is located under more than one section, you can view the man page for that command from a specific section as shown below.

$ man SECTION-NUMBER commandname

Following 8 sections are available in the man page.

    General commands
    System calls
    C library functions
    Special files (usually devices, those found in /dev) and drivers
    File formats and conventions
    Games and screensavers
    System administration commands and daemons

For example, when you do whatis crontab, you’ll notice that crontab has two man pages (section 1 and section 5). To view section 5 of crontab man page, do the following.

$ whatis crontab
crontab (1)          - maintain crontab files for individual users (V3)
crontab (5)          - tables for driving cron

$ man 5 crontab

42. tail command examples
Print the last 10 lines of a file by default.

$ tail filename.txt

Print N number of lines from the file named filename.txt

$ tail -n N filename.txt

View the content of the file in real time using tail -f. This is useful to view the log files, that keeps growing. The command can be terminated using CTRL-C.

$ tail -f log-file

More tail examples: 3 Methods To View tail -f output of Multiple Log Files in One Terminal

43. less command examples
less is very efficient while viewing huge log files, as it doesn’t need to load the full file while opening.

$ less huge-log-file.log

One you open a file using less command, following two keys are very helpful.

CTRL+F – forward one window
CTRL+B – backward one window

More less examples: Unix Less Command: 10 Tips for Effective Navigation

44. su command examples
Switch to a different user account using su command. Super user can switch to any other user without entering their password.


Execute a single command from a different account name. In the following example, john can execute the ls command as raj username. Once the command is executed, it will come back to john’s account.

[john@dev-server]$ su - raj -c 'ls'


Login to a specified user account, and execute the specified shell instead of the default shell.


45. mysql command examples
mysql is probably the most widely used open source database on Linux. Even if you don’t run a mysql database on your server, you might end-up using the mysql command ( client ) to connect to a mysql database running on the remote server.

To connect to a remote mysql database. This will prompt for a password.

$ mysql -u root -p -h

To connect to a local mysql database.

$ mysql -u root -p

If you want to specify the mysql root password in the command line itself, enter it immediately after -p (without any space).

46. yum command examples
To install apache using yum.

$ yum install httpd

To upgrade apache using yum.

$ yum update httpd

To uninstall/remove apache using yum.

$ yum remove httpd

47. rpm command examples
To install apache using rpm.

# rpm -ivh httpd-2.2.3-22.0.1.el5.i386.rpm

To upgrade apache using rpm.

# rpm -uvh httpd-2.2.3-22.0.1.el5.i386.rpm

To uninstall/remove apache using rpm.

# rpm -ev httpd

More rpm examples: RPM Command: 15 Examples to Install, Uninstall, Upgrade, Query RPM Packages

48. ping command examples
Ping a remote host by sending only 5 packets.

$ ping -c 5

More ping examples: Ping Tutorial: 15 Effective Ping Command Examples

49. date command examples
Set the system date:

# date -s "01/31/2010 23:59:53"

Once you’ve changed the system date, you should syncronize the hardware clock with the system date as shown below.

# hwclock –systohc

# hwclock --systohc –utc

50. wget command examples
The quick and effective method to download software, music, video from internet is using wget command.

$ wget


Visitors Info.

You are from
%%v_FLG%% %%v_IP%%
%%v_CR%% ,%%v_RG%%, %%v_CI%%
%%v_OS_IMG%% %%v_OS%%
%%v_BRW_IMG%% %%v_BRW%%
%%v_I_RESO%% %%v_RESO%% %%v_I_CLR%% %%v_CLR%% Webutation Creative Commons License
Hacker Konka by Konka Karthik is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.
Back To Top