The linux admins one useful command called Screen in Linux

screen

Screen command offers the ability to detach a long running process (or program, or shell-script) from a session and then attach it back at a later time.

When the session is detached, the process that was originally started from the screen is still running and managed by the screen. You can then re-attach the session at a later time, and your terminals are still there, the way you left them.

In this article, let us review the how to manage the virtual terminal sessions using screen command with examples.

Screen Command Example 1: Execute a command (or shell-script), and detach the screen

Typically you’ll execute a command or shell-script as shown below from the command.

$ unix-command-to-be-executed

$ ./unix-shell-script-to-be-executed

Instead, use the screen command as shown below.

$ screen unix-command-to-be-executed

$ screen ./unix-shell-script-to-be-executed

Once you’ve used the screen command, you can detach it from the terminal using any one of the following method.

Screen Detach Method 1: Detach the screen using CTRL+A d

When the command is executing, press CTRL+A followed by d to detach the screen.

Screen Detach Method 2: Detach the screen using -d option

When the command is running in another terminal, type the command as following.

$ screen -d SCREENID

Screen Command Example 2: List all the running screen processes

You can list all the running screen processes using screen -ls command.

For example:

On terminal 1 you did the following:

$ screen ./myscript.sh

From terminal 2 you can view the list of all screen processes. You can also detach it from terminal 2 as shown below.

$ screen -ls
There is a screen on:
	4491.pts-2.FC547	(Attached)
1 Socket in /var/run/screen/S-sathiya.

$ screen -d 4491.pts-2.FC547
[4491.pts-2.FC547 detached.]

Screen Command Example 3: Attach the Screen when required

You can attach the screen at anytime by specifying the screen id as shown below. You can get the screen id from the “screen -ls” command output.

$ screen -r 4491.pts-2.FC547

Screen Command Usage Scenario 1

When you have access to only one terminal, you can use screen command to multiplex the single terminal into multiple, and execute several commands. You might also find it very useful to combine the usage of screen command along with the usage of SSH ControlMaster.

Screen Command Usage Scenario 2

When you are working in a team environment, you might walk over to your colleagues desk and get few things clarified. At that time, if needed, you can even start some process from their machine using screen command and detach it when you are done. Later when you get back to your desk, you can login and attach the screen back to your terminal.

 source/reference

How to Invoke Script made using Bash

Invoking bash

So you made your script. Now you need to test it by running it. You can invoke it by sh <scriptname>, or alternatively bash <scriptname>.(Not recommended is using sh <scriptname>, since this effectively disables reading from stdin within the script.) Much more convenient is to make the script itself directly executable with a chmod.
Either:

chmod 555 scriptname

(gives everyone read/execute permission)

or

chmod +rx scriptname

(gives everyone read/execute permission)

 or

chmod u+rx scriptname

(gives only the script owner read/execute permission)

 

Having made the script executable, you may now test it by ./scriptname.  If it begins with a “sha−bang” line, invoking the script calls the correct command interpreter to run it.

As a final step, after testing and debugging, you would likely want to move it to /usr/local/bin (as root,of course), to make the script available to yourself and all other users as a system−wide executable. The script could then be invoked by simply typing scriptname[ENTER] from the command line.

ASCII – Special Characters – Alt Keyboard Shortcuts

extend
ASCII

To type a special character, using an Alt keyboard sequence

1. Make sure that the Num Lock key has been pressed, to activate the numeric key section of the keyboard.

2. Press and hold down the Alt key.                        3. While the Alt key is pressed, type the sequence of numbers (on the numeric keypad) from the Alt code in the above table.

4. Release the Alt key, and the character will appear.

Some sequence from the above table skipped since no symbol representation or duplicate symbol.

How to Install memcached in Centos 6

memcached

I was building a website of my own and was onmy testing phase when I noticed its a little bit slow. It might be because i have too many graphics loading and heavy database when doing some searching. I searched Google ways to speed up websites and i found out about memcached and found some article on how to install the said application. I tried it and I noticed a big difference on my website’s performance.

MEMCACHED DEFINITION

Memcached is a distributed, high-performance, in-memory caching system that is primarily used to speed up sites that make heavy use of databases. It can however be used to store objects of any kind. Nearly every popular CMS has a plugin or module to take advantage of memcached, and many programming languages have a memcached library, including PHP, Perl, Ruby, and Python. Memcached runs in-memory and is thus quite speedy, since it does not need

to write to disk.

Here’s how to install it on CentOS 6:

Memcached does have some dependencies that need to be in place. Install libevent using yum:

yum install libevent libevent-devel

The memcached install itself starts with

To start installing memcached, change your working directory to /usr/local/src and download the latest memcached source:

cd /usr/local/src 
wget http://memcached.googlecode.com/files/memcached-1.4.15.tar.gz

Uncompress the tarball you downloaded and change into the directory that is created:

tar xvzf memcached-1.4.15.tar.gz
cd memcached-1.4.15

Note:

Check memcached.org for a newer version before proceeding with the installation. Their might be newer version existing after the publication of this post. Please note the tarball version we are using is 1.4.15.

Next, configure your Makefile. The simplest way is to run:

./configure

Additional configure flags are available and can improve performance if your server is capable. For 64-bit OSes, you can enable memcached to utilize a larger memory allocation than is possible with 32-bit OSes:

./configure --enable-64bit

If your server has multiple CPUs or uses multi-core CPUs, enable threading:

./configure --enable-threads

If your server supports it, you can use both flags:

./configure --enable-threads --enable-64bit

n.b.: if the configure script does not run, you may have to install compiling tools on your server. That is as simple as

yum install gcc
yum install make

Once the configure script completes, build and install memcached:

make && make install

Last but not least, start a memcached server:

memcached -d -u nobody -m 512 -p 11211 127.0.0.1

Put another way, the previous command can be laid out like this:

memcached -d -u [user] -m [memory size] -p [port] [listening IP]

Let’s go over what each switch does in the above command:

-d
Tell memcached to start up as a backgrounded daemon process
-u
Specify the user that you want to run memcached
-m
Set the memory that you want to be allocated my memcached
-p
The port on which memcached will listen.

Now your site is ready for a fast run literally.

Resources:

http://memcached.org/

http://www.liquidweb.com/kb/how-to-install-memcached-on-centos-6/

How to recover mysql root password in Linux

mysql

I installed my mysql two months ago and got busy afterwards. I already set everything, root password, permissions, cron for dump, phpmyadminl and some other stuffs. Since i got busy, never had a chance to explore and go back until now. But the problem is, i forgot the root password i set. In case you need to recover the root password in Linux here are some steps that can help you.

 

 

Step # 1: Stop the MySQL server process.

Step # 2: Start the MySQL (mysqld) server/daemon process with the –skip-grant-tables option so that it will not prompt for password.

Step # 3: Connect to mysql server as the root user.

Step # 4: Setup new mysql root account password i.e. reset mysql password.

Step # 5: Exit and restart the MySQL server.

 

The corresponding commands to use in accordance to above steps are the following.  Make sure you are logged as root in your linux box when doing it.

Step # 1 : Stop mysql service

# /etc/init.d/mysql stop

Output:

Stopping MySQL database server: mysqld.

Step # 2: Start to MySQL server w/o password:

# mysqld_safe --skip-grant-tables &

Output:

130607 14:16:49  mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql
130607 14:16:49  InnoDB: Initializing buffer pool, size = 8.0M
130607 14:16:49  InnoDB: Completed initialization of buffer pool
130607 14:16:49  InnoDB: Started; log sequence number 0 44233

Step # 3: Connect to mysql server using mysql client:

# mysql -u root

Output:

Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 1 to server version: 4.1.15-Debian_1-log
Type 'help;' or '\h' for help. Type '\c' to clear the buffer.
mysql>

Step # 4: Setup new MySQL root user password

mysql> use mysql;
mysql> update user set password=PASSWORD("New_root_password") where User='root';
mysql> flush privileges;
mysql> quit

Step # 5: Stop MySQL Server:

# /etc/init.d/mysql stop

Output:

Stopping MySQL database server: mysqld
STOPPING server from pid file /var/run/mysqld/mysqld.pid
mysqld_safe[6186]: ended
[1]+  Done                    mysqld_safe --skip-grant-tables

Step # 6: Start MySQL server and test it

# /etc/init.d/mysql start
# mysql -u root -p

 

Reference

20 Most used Linux-based system monitoring tools

tuxsysad

The following are some of the  basic CLI, GUI, TUI commands to use in monitoring linux operated systems and helps in in-depth system analysis and debugging of server problems. These commands commonly help resolve issues regarding CPU, Memory, Network, and Storage.

1: top – Process Activity Command

The top program provides a dynamic real-time view of a running system i.e. actual process activity. By default, it displays the most CPU-intensive tasks running on the server and updates the list every five seconds.

#top 
top

top

2: vmstat – System Activity, Hardware and System Information

The command vmstat reports information about processes, memory, paging, block IO, traps, and cpu activity.

#vmstat -a
vmstat

vmstat

3: w – Find Out Who Is Logged on And What They Are Doing

w command displays information about the users currently on the machine, and their processes.

# w testuser 
w

w

4: uptime – Tell How Long The System Has Been Running

The uptime command can be used to see how long the server has been running. The current time, how long the system has been running, how many users are currently logged on, and the system load averages for the past 1, 5, and 15 minutes.

# uptime
uptime

uptime

1 can be considered as optimal load value. The load can change from system to system. For a single CPU system 1 – 3 and SMP systems 6-10 load value might be acceptable.

5: ps – Displays The Processes

ps

ps

ps command will report a snapshot of the current processes. To select all processes use the -A or -e option:

# ps -A

ps is just like top but provides more information.

Show Long Format Output

# ps -Al
To turn on extra full mode (it will show command line arguments passed to process):
# ps -AlF

To See Threads ( LWP and NLWP)

# ps -AlFH

To See Threads After Processes

# ps -AlLm

Print All Process On The Server

# ps ax
# ps axu

Print A Process Tree

# ps -ejH
# ps axjf
# pstree

Print Security Information

# ps -eo euser,ruser,suser,fuser,f,comm,label
# ps axZ
# ps -eM

See Every Process Running As User testuser

# ps -U testuser -u testuser u

Set Output In a User-Defined Format

# ps -eo pid,tid,class,rtprio,ni,pri,psr,pcpu,stat,wchan:14,comm
# ps axo stat,euid,ruid,tty,tpgid,sess,pgrp,ppid,pid,pcpu,comm
# ps -eopid,tt,user,fname,tmout,f,wchan

Display Only The Process IDs of Lighttpd

# ps -C lighttpd -o pid=
OR
# pgrep lighttpd
OR
# pgrep -u testuser php-cgi

Display The Name of PID 55977

# ps -p 55977 -o comm=

Find Out The Top 10 Memory Consuming Process

# ps -auxf | sort -nr -k 4 | head -10

Find Out top 10 CPU Consuming Process

# ps -auxf | sort -nr -k 3 | head -10

6: free - Memory Usage 

The command free displays the total amount of free and used physical and swap memory in the system, as well as the buffers used by the kernel.

# free 
free

free

7: iostat – Average CPU Load, Disk Activity

The command iostat report Central Processing Unit (CPU) statistics and input/output statistics for devices, partitions and network filesystems (NFS).

# iostat 
iostat

iostat

8: sar – Collect and Report System Activity

The sar command is used to collect, report, and save system activity information. To see network counter, enter:

sar

sar

# sar -n DEV | more
To display the network counters from the 24th:
# sar -n DEV -f /var/log/sa/sa24 | more
You can also display real time usage using sar:
# sar 4 5

9: mpstat – Multiprocessor Usage

The mpstat command displays activities for each available processor, processor 0 being the first one. mpstat -P ALL to display average CPU utilization per processor:

# mpstat -P ALL
mpstat

mpstat

10: pmap – Process Memory Usage

The command pmap report memory map of a process. Use this command to find out causes of memory bottlenecks.

# pmap -d PID 

To display process memory information for pid # 47394, enter:

# pmap -d 47394 
pmap

pmap

11 netstat – Network Statistics

The command netstat displays network connections, routing tables, interface statistics, masquerade connections, and multicast memberships

netstat

netstat

12: ss – Network Statistics

ss command is used to dump socket statistics. It allows showing information similar to netstat.

ss

ss

13: iptraf – Real-time Network Statistics

The iptraf command is interactive colorful IP LAN monitor. It is an ncurses-based IP LAN monitor that generates various network statistics including TCP info, UDP counts, ICMP and OSPF information, Ethernet load info, node stats, IP checksum errors, and others. It can provide the following info in easy to read format:

  • Network traffic statistics by TCP connection
  • IP traffic statistics by network interface
  • Network traffic statistics by protocol
  • Network traffic statistics by TCP/UDP port and by packet size
  • Network traffic statistics by Layer2 address
iptraf1

iptraf1

iptraf2

iptraf2

14: tcpdump – Detailed Network Traffic Analysis

The tcpdump is simple command that dump traffic on a network. However, you need good understanding of TCP/IP protocol to utilize this tool. For.e.g to display traffic info about DNS, enter:

 # tcpdump -i eth0 'tcp port 80'

To display all IPv4 HTTP packets to and from port 80, i.e. print only packets that contain data, not, for example, SYN and FIN packets and ACK-only packets, enter:

# tcpdump 'tcp port 80 and (((ip[2:2] - ((ip[0]&0xf)<<2)) - ((tcp[12]&0xf0)>>2)) != 0)' 

To display all FTP session to 202.54.1.5, enter:

# tcpdump -i eth1 'dst 202.54.1.5 and (port 21 or 20' 

To display all HTTP session to 192.168.1.5:

# tcpdump -ni eth0 'dst 192.168.1.5 and tcp and port http'

Use wireshark to view detailed information about files, enter:

# tcpdump -n -i eth1 -s 0 -w output.txt src or dst port 80 
tcpdump

tcpdump

15: strace – System Calls

Trace system calls and signals. This is useful for debugging webserver and other server problems. See how to use to trace the process and see What it is doing.

Strace

Strace

16: /Proc file system – Various Kernel Statistics

/proc file system provides detailed information about various hardware devices and other Linux kernel information. See Linux kernel /proc documentations for further details. Common /proc examples:

# cat /proc/cpuinfo
# cat /proc/meminfo
# cat /proc/zoneinfo
# cat /proc/mounts
proc

proc

17: Nagios – Server And Network Monitoring

Nagios is a popular open source computer system and network monitoring application software. You can easily monitor all your hosts, network equipment and services. It can send alert when things go wrong and again when they get better. FAN is “Fully Automated Nagios”. FAN goals are to provide a Nagios installation including most tools provided by the Nagios Community. FAN provides a CDRom image in the standard ISO format, making it easy to easilly install a Nagios server. Added to this, a wide bunch of tools are including to the distribution, in order to improve the user experience around Nagios. See how to install Nagios

nagios

nagios

18: Cacti – Web-based Monitoring Tool

Cacti is a complete network graphing solution designed to harness the power of RRDTool’s data storage and graphing functionality. Cacti provides a fast poller, advanced graph templating, multiple data acquisition methods, and user management features out of the box. All of this is wrapped in an intuitive, easy to use interface that makes sense for LAN-sized installations up to complex networks with hundreds of devices. It can provide data about network, CPU, memory, logged in users, Apache, DNS servers and much more. See how to install and configure Cacti network graphing tool on linux box.

cacti

cacti

19: KDE System Guard – Real-time Systems Reporting and Graphing

KSysguard is a network enabled task and system monitor application for KDE desktop. This tool can be run over ssh session. It provides lots of features such as a client/server architecture that enables monitoring of local and remote hosts. The graphical front end uses so-called sensors to retrieve the information it displays. A sensor can return simple values or more complex information like tables. For each type of information, one or more displays are provided. Displays are organized in worksheets that can be saved and loaded independently from each other. So, KSysguard is not only a simple task manager but also a very powerful tool to control large server farms.

kdesystemguard

kdesystemguard

20: Gnome System Monitor – Real-time Systems Reporting and Graphing

The System Monitor application enables you to display basic system information and monitor system processes, usage of system resources, and file systems. You can also use System Monitor to modify the behavior of your system. Although not as powerful as the KDE System Guard, it provides the basic information which may be useful for new users:

  • Displays various basic information about the computer’s hardware and software.
  • Linux Kernel version
  • GNOME version
  • Hardware
  • Installed memory
  • Processors and speeds
  • System Status
  • Currently available disk space
  • Processes
  • Memory and swap space
  • Network usage
  • File Systems
  • Lists all mounted filesystems along with basic information about each.
gnome-system-monitor

gnome-system-monitor

More Tools of interest

A few more tools:

  • nmap – scan your server for open ports.
  • lsof – list open files, network connections and much more.
  • ntop web based tool – ntop is the best tool to see network usage in a way similar to what top command does for processes i.e. it is network traffic monitoring software. You can see network status, protocol wise distribution of traffic for UDP, TCP, DNS, HTTP and other protocols.
  • Conky – Another good monitoring tool for the X Window System. It is highly configurable and is able to monitor many system variables including the status of the CPU, memory, swap space, disk storage, temperatures, processes, network interfaces, battery power, system messages, e-mail inboxes etc.
  • GKrellM – It can be used to monitor the status of CPUs, main memory, hard disks, network interfaces, local and remote mailboxes, and many other things.
  • vnstat – vnStat is a console-based network traffic monitor. It keeps a log of hourly, daily and monthly network traffic for the selected interface(s).
  • htop – htop is an enhanced version of top, the interactive process viewer, which can display the list of processes in a tree form.
  • mtr – mtr combines the functionality of the traceroute and ping programs in a single network diagnostic tool.
  • wireshark - is a free and open-source packet analyzer. It is used for network troubleshooting, analysis, software and communications protocol development, and education. Originally named Ethereal, in May 2006 the project was renamed Wireshark due to trademark issues.
  • snort – Snort’s open source network-based intrusion detection system (NIDS) has the ability to perform real-time traffic analysis and packet logging on Internet Protocol (IP) networks. Snort performs protocol analysis, content searching, and content matching. The program can also be used to detect probes or attacks, including, but not limited to, operating system fingerprinting attempts, common gateway interface, buffer overflows, server message block probes, and stealth port scans.
  • Centreon – Centreon is an Open Source software package that lets you supervise all the infrastructures and applications comprising your information system.

References:

http://www.cyberciti.biz/tips/top-linux-monitoring-tools.html

http://www.wireshark.org/about.html

Invoking GUI Network tool on Centos 6

 nm-connection-editor

you need to first install NetworkManager using YUM

yum install NetworkManager

Or check it is already started or not

service NetworkManager status

else start the service

service NetworkManager start
chkconfig NetworkManager on

To open to GUI interface you need to execute “nm-applet” command. and to configure or edit configurations “nm-connection-editor” use this command

nm-applet
nm-connection-editor (note: this command is formerly known as system-config-network-gui)

Snort (Intrusion Detection Utility) Installation in Centos 6

snort

Definition

snort2SNORT  is a free and open source network intrusion prevention system (NIPS) and network intrusion detection system (NIDS)[2] created by Martin Roesch in 1998.Snort is now developed by Sourcefire, of which Roesch is the founder and CTO.In 2009, Snort entered InfoWorld’s Open Source Hall of Fame as one of the “greatest [pieces of] open source software of all time”.

Snort’s open source network-based intrusion detection system (NIDS) has the ability to perform real-time traffic analysis and packet logging on Internet Protocol (IP) networks. Snort performs protocol analysis, content searching, and content matching. The program can also be used to detect probes or attacks, including, but not limited to, operating system fingerprinting attempts, common gateway interface, buffer overflows, server message block probes, and stealth port scans.

Snort can be configured in three main modes: sniffer, packet logger, and network intrusion detection. In sniffer mode, the program will read network packets and display them on the console. In packet logger mode, the program will log packets to the disk. In intrusion detection mode, the program will monitor network traffic and analyze it against a rule set defined by the user. The program will then perform a specific action based on what has been identified.

Before proceeding with Snort installation you will need to install the required packages.  Follow the steps to do prior to snort’s installation.

Pre-Installation

Make sure to have the latest version of  MySQL, HTTP, Development Tools and Development Libraries.

     Install the necessary packages needed to run snort successfully.

 #yum install mysql-bench mysql-devel php-mysql gcc php-gd gd glib2-devel gcc-c++

      Yum install libcap, libpcap and pcre

#yum install libcap*
#yum install libpcap*
#yum install pcre*

      Install libdnet 1.12

#cd /
#mkdir snort_install
#cd snort_install
#wget http://libdnet.googlecode.com/files/libdnet-1.12.tgz
#tar -zxvf libdnet-1.12.tgz
#cd libdnet-1.12
#./configure
#make && make install

     Install daq version 2.0.0

#cd /snort_install
#wget http://www.snort.org/downloads/2103
#tar -zxvf daq-2.0.0.tar.gz
#cd daq-2.0.0
#./configure
#make && make install

     Install snort version 2.9.4

#cd /snort_install
#wget http://www.snort.org/downloads/2112
#tar -zxvf snort-2.9.4.tar.gz
#cd snort-2.9.4
#./configure
#make && make install

Post Installation Instruction

      prepare for rules installation

# groupadd snort
# useradd -g snort snort -s /sbin/nologin
# mkdir /etc/snort
# mkdir /etc/snort/rules
# mkdir /etc/snort/so_rules
# mkdir /etc/snort/preproc_rules
# mkdir /var/log/snort
# chown snort:snort /var/log/snort
# mkdir /usr/local/lib/snort_dynamicrules
# cd /snort_install/snort-2.9.4/etc/
# cp * /etc/snort/

      Register on Snort official web site and download rules to  /snort_install directory

#cd /snort_install
#tar -zxvf snortrules-snapshot-2940.tar.gz
#cd rules/
#cp * /etc/snort/rules
#cp ../so_rules/precompiled/Centos-5-4/i386/2.9.4.0/* /etc/snort/so_rules
#cp ../preproc_rules/* /etc/snort/preproc_rules/

     Edit /etc/snort/snort.conf file

1.change “var RULE_PATH ../rules” to “var RULE_PATH /etc/snort/rules”,
change “var SO_RULE_PATH ../so_rules” to “var SO_RULE_PATH /etc/snort/so_rules”,
change “var PREPROC_RULE_PATH ../preproc_rules” to “var PREPROC_RULE_PATH /etc/snort/preproc_rules”
2. comment on the whole “Reputation preprocessor” section, because we haven’t whitelist file
3. find “Configure output plugins” section and add the line “output unified2: filename snort.log, limit 128″

    Install Barnyard 2

#cd /snort_install
#wget http://www.securixlive.com/download/barnyard2/barnyard2-1.9.tar.gz
#tar -zxvf barnyard2-1.9.tar.gz 
#cd barnyard2-1.9
#./configure 
#./configure --with-mysql-libraries=/usr/lib/mysql/
#make 
#make install
#cp etc/barnyard2.conf /etc/snort/
#mkdir /var/log/barnyard2
#chmod 666 /var/log/barnyard2
#touch /var/log/snort/barnyard2.waldo

       Setup MySQL Database

#echo "SET PASSWORD FOR root@localhost=PASSWORD('yourpassword');"| mysql -u root -p
#echo "create database snort;"| mysql -u root -p
#cd /snort_install/barnyard2-1.9
#mysql -u root -p -D snort < schemas/create_mysql
#echo "grant create, insert on root.* to snort@localhost;" | mysql -u root -p
#echo "SET PASSWORD FOR snort@localhost=PASSWORD('yourpassword');" | mysql -u root -p
#echo "grant create,insert,select,delete,update on snort.* to snort@localhost" | mysql -u root -p

     Edit the file /etc/snort/barnyard2.conf

change “config hostname: thor” to “config hostname: localhost”

change “config interface: eth0″ to “config interface: eth1″

add the line at the end of file “output database: log, mysql, user=snort password=yourpassword dbname=snort     host=localhost”
Note: the device eth1 may vary depending on your system set-up. The example given above is a 2 network device(eth0,eth1) setup where snort was applied to the second network device(eth1)
 

      Test

#/usr/local/bin/snort -u snort -g snort -c /etc/snort/snort.conf -i eth1

    If it prompts “Initialization Complete”, it proves to work.

      or  Execute snort from command line

#snort -c /etc/snort/snort.conf -l /var/log/snort/

If testing and manual run working perfectly fine proceed with the next step

      Make Snort and Barnyard2 boot up automatically

Edit the file /etc/rc.local, add the below lines

/sbin/ifconfig eth1 up /usr/local/bin/snort -D -u snort -g snort -c /etc/snort/snort.conf -i eth1

/usr/local/bin/barnyard2 -c /etc/snort/barnyard2.conf -d /var/log/snort -f snort.log -w /var/log/snort   /barnyard2.waldo -D

Restart to test changes.

#init 6

References:

http://www.snort.org/

http://en.wikipedia.org/wiki/Snort_%28software%29

http://www.securixlive.com/

http://kezhong.wordpress.com/2012/04/07/install-snort-2-9-2-2-on-centos5-8x86_64/http://www.securixlive.com/

Analyze, Find, Review and Delete Duplicate files in Windows and Linux

 

I was having problems with my pc storage space sometime ago. So basically i need to  go over all the files i have in my pc and have a hard time condescending which files/folders to delete to free up space. So i decided to analyze in which directory i should start. So in my perspective i cannot recursively go down each directory just to find which eats up most space. So i used WinDirStat  to check disk usage.

After scanning your system, WinDirStat shows you exactly which folders, file types, and files are using the most space. Ensure you don’t delete any important system files – only delete personal data files. If you see a program’s folder in the Program Files folder using a large amount of space, you can uninstall that program – WinDirStat can tell you just how much space a program is using, even if the Programs and Features Control Panel doesn’t.

windirstat

windirstat

 

Definition:

Download WinDirStat here

WinDirStat is a disk usage statistics viewer and cleanup tool for various versions of Microsoft Windows.
Note: if you are looking for an alternative for Linux, you are looking for KDirStat (apt-get install kdirstat on Debian-derivatives) and for MacOS X it would be Disk Inventory X or GrandPerspective.

 

So now i know which directories to move forward too. I browsed the contents to check. I found out that there are duplicate files in these different locations/folders but it would take weeks before i finish manually searching for those duplicate files. Luckily i found this application that search, let’s you review and delete the duplicate files in your chosen directory.  The application’s name is dupeGuru.  But it would let you delete only 10 at a time for the free version, but if you want to do chosen action without any restrictions you need to purchase the full version.

dupeGuru

dupeGuru

 

Definition:

Download dupeGuru here

dupeGuru is a tool to find duplicate files on your computer. It can scan either filenames or contents. The filename scan features a fuzzy matching algorithm that can find duplicate filenames even when they are not exactly the same. dupeGuru runs on Windows, Mac OS X and Linux.

 

 

Features

dupeGuru is efficient.

Find your duplicate files in minutes, thanks to its quick fuzzy matching algorithm. dupeGuru not only finds filenames that are the same, but it also finds similar filenames.

dupeGuru is customizable.

You can tweak its matching engine to find exactly the kind of duplicates you want to find. The Preference page of the help file lists all the scanning engine settings you can change.

dupeGuru is safe.

Its engine has been especially designed with safety in mind. Its reference directory system as well as its grouping system prevent you from deleting files you didn’t mean to delete.

Do whatever you want with your duplicates.

Not only can you delete duplicates files dupeGuru finds, but you can also move or copy them elsewhere. There are also multiple ways to filter and sort your results to easily weed out false duplicates (for low threshold scans).

Supported languages:

English, French, German, Chinese (Simplified), Czech, Italian, Armenian, Russian, Ukrainian, Brazilian.

After doing some clean up using the applications above a whopping 35 G was been added to my free space. That’s really something. Try it yourself! Have a happy time cleaning your pc.