Kurinchi Blogger Scribbles …


Archive for the ‘LINUX’ Category

Feb 01
2013

How to install PHPSECLIB on a WAMP environment with PEAR setup?

Last updated: March 1st, 2013

PEAR should be already installed in the system before configuring the phpseclib channel.

PHPSecLib installation is very simple.

PHPSecLib is a library of optional PHP extensions which comes in handy if the application were to be packaged as a solution for deployment to the end user.

Step 1: Register the channel

c:\> pear channel-discover phpseclib.sourceforge.net
(more…)

Jan 10
2013

How to remove ^M characters at the end of lines in Vi from files in Linux?

Last updated: February 6th, 2013

Files created in windows when moved to linux will have ^M character at the end of lines when you open the files in Vi editor.

To remove the strange characters open the file in Vi editor and type

:%s/.$// 

(more…)

Dec 06
2012

How to determine the file system type in Linux?

Last updated: February 6th, 2013

Linux supports many file system types like Ext2, Ext3, Ext4, NFS, FAT16, FAT32, NTFS etc. To find out what type of file systems are mounted in your system, issue the command

$ df -T

Output from the command

Filesystem    Type   1K-blocks      Used Available Use% Mounted on
/dev/sda1     ext4    94088076   9090252  80218356  11% /
udev      devtmpfs     1023536         4   1023532   1% /dev
Nov 24
2012

How to find the port used by mysql?

Last updated: November 24th, 2012

List the listening ports and check if mysql is listed on it.

$ netstat -tln | grep mysql

If you cannot find the port number for mysql view my.cnf file to see if you can find the port number. If you see a line “skip-networking” try commenting out the line and then restart mysql daemon.

$ vi /etc/my.cnf

[mysqld]
set-variable=local-infile=0
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
# Default to using old password format for compatibility with mysql 3.x
# clients (those using the mysqlclient10 compatibility package).
old_passwords=1
skip-networking

[mysql.server]
user=mysql
basedir=/var/lib

[mysqld_safe]
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid

$ service mysqld restart

Nov 12
2012

How to install and setup Fail2ban on CentOS?

Last updated: November 12th, 2012

Fail2ban is a software used to ban IP’s which shows strange behavior. It can be configured to reject IP’s for a certain amount of time.

To install Fail2ban we need to download the application from the source. Login as the root user and go to /opt

$ cd /opt

$ wget http://downloads.sourceforge.net/project/fail2ban/fail2ban-stable/fail2ban-0.8.4/fail2ban-0.8.4.tar.bz2?use_mirror=transact

Next unzip the downloaded file

$ tar -xf fail2ban-0.8.4.tar.bz2

$ cd fail2ban-0.8.4
(more…)

Oct 02
2012

How to setup Rails on WAMP server using HTTP Proxy module?

Last updated: October 3rd, 2012

To setup Rails on windows after Ruby and Rails setup,

i) Edit hosts file in windows environment and set the server name in the hosts file to

127.0.0.1 myrails

In this example, i have used “myrails” as the server name for the project.

ii) Edit httpd configuration setting on WAMP to make sure proxy and proxy_http module is turned on (check if it those lines are not commented out)

LoadModule proxy_module modules/mod_proxy.so
LoadModule proxy_http_module modules/mod_proxy_http.so

(more…)

Oct 01
2012

How to install Ruby, Rails and MySQL on Ubuntu Server?

Last updated: October 1st, 2012

For this tutorial we will be using Ruby 1.9.3 and Rails 3.2.1

First thing update
$ sudo apt-get update

Next, we are going to install git, RVM which is essential for the build

$sudo apt-get install build-essential git-core curl

RVM stands for Ruby Version Manager that is used for installing and managing multiple versions of Ruby at one point of time.
(more…)

Sep 25
2012

How to check Python version number in Linux/Unix environment?

Last updated: September 25th, 2012

To check the Python version number in Linux, simply type


$ python -V

You will get an output

Python 2.4.3
Sep 11
2012

Apache: How to deny access to a folder or file?

Last updated: September 8th, 2012

Add the following list of lines into .htaccess file or to vhost configuration file appropriate to the folder within the website

<Directory /securedata>
Order Deny,Allow
Deny from all
</Directory>

Same will be the case for denying files within directories

<Files ~ “\.ini$”>
Order allow,deny
Deny from all
</Files>

The above lines of code will be helpful for us to prevent .svn files, .ini files, .htaccess files, include files from display within Apache

Sep 09
2012

SQL Injection: Whitelist validation vs. blacklist validation

Last updated: September 8th, 2012

Whitelist validation refers to data validation techniques such as checking the data type, data length, input range, nature of data by its format (for e.g. phone number will be ten digits separated by hyphens satisfying the format nnn-nnn-nnnn). Regular expressions may be used for format validation in inputs.

Blacklist validation refers to rejecting data based on a know bad list filter. This is not a powerful solution as the list of possible exclusions will be many and it is difficult to implement all possible scenarios. Blacklist validation should be used in conjunction with whitelist validation but in cases where whitelist validation cannot be applied at least blacklist validation should be implemented.


Valid HTML 4.01 Strict  Valid HTML 4.01 Strict