Unixbhaskar's Blog

Sunday, October 31, 2010

Rsync : A handy tool to sync with

In this article I am going to show you some implication of rsync tool.It is a tool often used by the web masters and system administrator to sync with various number of host across the network.Now what is the utility of having rsync under your armory? The advantage is quite useful.Here are few:

** It can sync filesystem across the network

** It can only sync the updated version the filesystem then the whole tree.

** It is very useful to copy the entire web site ported to new host or hosts.

** Rsync can do a various job related to backup procedure.

support for copying links, devices, owners, groups, and permissions

** exclude and exclude-from options similar to GNU tar

** a CVS exclude mode for ignoring the same files that CVS would ignore

** can use any transparent remote shell, including ssh or rsh

** does not require super-user privileges

** pipelining of file transfers to minimize latency costs

** support for anonymous or authenticated rsync daemons (ideal for mirroring)

Above stated advantages are name a few.Kindly look into the manual page of it.So,now I have four different partition and and I want to sync a particualr dir with all partiotn with a specific application running on all the OSes.

The idea is to get it sync; because I want the information to be indentical across all the partitions(same can be applied to different hosts too over the network!!).

How does it work?

You must set up one machine or another of a pair to be an "rsync server" by running rsync in a daemon mode ("rsync --daemon" at the commandline) and setting up a short, easy configuration file (/etc/rsyncd.conf). Below I'll detail a sample configuration file. The options are readily understood, few in number -- yet quite powerful.

Any number of machines with rsync installed may then synchronize to and/or from the machine running the rsync daemon. You can use this to make backups, mirror filesystems, distribute files or any number of similar operations. Through the use of the "rsync algorithm" which transfers only the diffs between files (similar to a patch file) and then compressing them -- you are left with a very efficient system.

For those of you new to secure shell ("ssh" for short), you should be using it! There's a very useful and quite thourough Getting Started with SSH document available. You may also want to visit the Secure Shell Web Site. Or, just hit the Master FTP Site in Finland and snag it for yourself. It provides a secure, encrypted "pipe" for your network traffic. You should be using it instead of telnet, rsh or rlogin and use the replacement "scp" command instead of "rcp."

Setting up a Server

You must set up a configuration file on the machine meant to be a server and run the rsync binary in daemon mode. Even your rsync client machines can run rsync in daemon mode for two-way transfers. You can do this automatically for each connection via the inet daemon or at the commandline in standalone mode to leave it running in the background for often repeated rsyncs. .Plus there is a CGI script that folks fire off frequently during the day for immediate updating of content. This is a lot of rsync calls! If you start off the rsync daemon through your inet daemon, then you incur much more overhead with each rsync call. You basically restart the rsync daemon for every connection your server machine gets! It's the same reasoning as starting Apache in standalone mode rather than through the inet daemon. It's quicker and more efficient to start rsync in standalone mode if you anticipate a lot of rsync traffic. Otherwise, for the occasional transfer follow the procedure to fire off rsync via the inet daemon. This way the rsync daemon, as small as it is, doesn't sit in memory if you only use it once a day or whatever. Your call.

Below is a sample rsync configuration file. It is placed in your /etc directory as rsyncd.conf.

motd file = /etc/rsyncd.motd
log file = /var/log/rsyncd.log
pid file = /var/run/
lock file = /var/run/rsync.lock

path = /rsync_files_here
comment = My Very Own Rsync Server
uid = nobody
gid = nobody
read only = no
list = yes
auth users = username
secrets file = /etc/rsyncd.scrt

Various options that you would modify right from the start are the areas in italics in the sample above. I'll start at the top, line by line, and go through what you should pay attention to. What the sample above does is setup a single "path" for rsync transfers to that machine.

Starting at the top are four lines specifying files and their paths for rsync running in daemon mode. The first is a "message of the day" (motd) file like you would use for an FTP server. This file's contents get displayed when clients connect to this machine. Use it as a welcome, warning or simply identification. The next line specifies a log file to send diagnostic and norml run-time messages to. The PID file contains the "process ID" (PID) number of the running rsync daemon. A lock file is used to ensure that things run smoothly. These options are global to the rsync daemon.

The next block of lines is specific to a "path" that rsync uses. The options contained therein have effect only within the block (they're local, not global options). Start with the "path" name. It's somewhat confusing that rsync uses the term "path" -- as it's not necessarily a full pathname. It serves as an "rsync area nickname" of sorts. It's a short, easy to remember (and type!) name that you assign to a try filesystem path with all the options you specify. Here are the things you need to set up first and foremost:

* path - this is the actual filesystem path to where the files are rsync'ed from and/or to.

* comment - a short, descriptive explanation of what and where the path points to for listings.

* auth users - you really should put this in to restrict access to only a pre-defined user that you specify in the following secrets file - does not have to be a valid system user.

* secrets file - the file containing plaintext key/value pairs of usernames and passwords.

One thing you should seriously consider is the "hosts allow" and "hosts deny" options for your path. Enter the IPs or hostnames that you wish to specifically allow or deny! If you don't do this, or at least use the "auth users" option, then basically that area of your filesystem is wide open to the world by anyone using rsync! Something I seriously think you should avoid...

Check the rsyncd.conf man page with "man rsyncd.conf" and read it very carefully where security options are concerned. You don't want just anyone to come in and rsync up an empty directory with the "--delete" option, now do you?

The other options are all explained in the man page for rsyncd.conf. Basically, the above options specify that the files are chmod'ed to uid/gid, the filesystem path is read/write and that the rsync path shows up in rsync listings. The rsync secrets file I keep in /etc/ along with the configuration and motd files, and I prefix them with "rsyncd." to keep them together.

For that reason I have mounted a partition which holds the updated version of the file and sync with others from that partition.

Say my Gentoo partition is updated and I want to update Arch,Fedora and Debian with I have mouted all of them in different designated dir under the / .

Here is how I can sync that perticular file :

bhaskar@bhaskar-laptop_06:55:11_Sun Oct 31:/srv/http/dokuwiki> sudo /usr/bin/rsync -avrP data/ /Fedora/var/www/html/dokuwiki/

I will update the output of it once it finished.With rsync the trailing slash (/) has a big role to play.It signifies that you want to copy all the contents of that dir instead of the dir.Without the trailing slash rsync will copy the entire directory.Now some explanation about the flags I have passed with the rsync. Here is the meaning of those;

a ------> It says that in the format of archive

v -------> verbose mode

r --------> recursive mode

P ---------> progress mode

It has many other useful options with deal with.Kindly look into the man pages for more details.But when you sync over the network you must use it over the ssh so the tunnel get secured during transfer.It has "-e" option which will allow you to pass an ssh option with it.



Hope this will help.


Thursday, October 14, 2010

DokuWiki : An opensource wiki to maintain information

In this article I will show you how you can install and use dokuwiki to keep your information in formatted manner.The biggest thing attract me that it uses flat file or plain text file to store information then backend database.So if you want to distribute the that file across different partition to get the same doc.Whereas in the corporate there should be separate dokuwiki server to maintain all the information.

Get the software:

bhaskar@bhaskar-laptop_16:24:53_Thu Oct 14:~/Documents> sudo yum install dokuwiki
[sudo] password for bhaskar:
Loaded plugins: presto, refresh-packagekit
google-chrome | 951 B 00:00
google-chrome/primary | 3.1 kB 00:00
google-chrome 5/5
openvz-kernel-rhel5 | 951 B 00:00
openvz-utils | 951 B 00:00
rpmfusion-free-updates | 2.8 kB 00:00
updates/metalink | 3.3 kB 00:00
updates | 4.7 kB 00:01
updates/primary_db | 5.0 MB 05:42
updates-source/metalink | 3.3 kB 00:00
updates-source | 3.3 kB 00:00
Setting up Install Process
Package dokuwiki-0-0.4.20091225.c.fc12.noarch already installed and latest version
Nothing to do

So it says I already have it and yes I had it long time back.Lets check out:

bhaskar@bhaskar-laptop_17:07:28_Thu Oct 14:~/Documents> sudo rpm -qi dokuwiki
[sudo] password for bhaskar:
Name : dokuwiki Relocations: (not relocatable)
Version : 0 Vendor: Fedora Project
Release : 0.4.20091225.c.fc12 Build Date: Tue 19 Jan 2010 04:23:45 PM IST
Install Date: Thu 23 Sep 2010 03:51:04 PM IST Build Host:
Group : Applications/Internet Source RPM: dokuwiki-0-0.4.20091225.c.fc12.src.rpm
Size : 6977076 License: GPLv2
Signature : RSA/8, Tue 19 Jan 2010 04:53:04 PM IST, Key ID 9d1cc34857bbccba
Packager : Fedora Project
Summary : Standards compliant simple to use wiki
Description :
DokuWiki is a standards compliant, simple to use Wiki, mainly aimed at creating
documentation of any kind. It has a simple but powerful syntax which makes sure
the datafiles remain readable outside the Wiki and eases the creation of
structured texts.

All data is stored in plain text files no database is required.

Lets find out the file that installed by this software:


.......output snipped for clarity

Hell lot of files get installed by the software.Next move on to installation of this software.We must have the top tree in the web space scope to get access through the browser.

bhaskar@bhaskar-laptop_17:20:58_Thu Oct 14:~/Documents> ls -al /var/www/html/dokuwiki/
total 44
drwxr-xr-x. 6 root root 4096 2010-09-23 18:08 .
drwxr-xr-x. 5 root root 4096 2010-09-24 18:15 ..
drwxr-xr-x. 2 root root 4096 2010-09-23 15:50 bin
drwxr-xr-x. 2 root root 4096 2010-09-23 18:10 conf
-rw-r--r--. 1 root root 2258 2010-09-23 16:01 doku.php
-rw-r--r--. 1 root root 11725 2010-01-17 16:05 feed.php
drwxr-xr-x. 5 root root 4096 2010-09-23 15:50 inc
-rw-r--r--. 1 root root 185 2010-09-23 16:09 index.php
drwxr-xr-x. 9 root root 4096 2010-09-23 15:51 lib

Now next job is go to the browser and invoke


Now a bit of file permission issue which might raised in the time or after the installation.Here is some point stright out of the dokuwiki site:

  • Permissions for a file are dependent of the file's owner and group and the user who tries to access the file
  • There are permissions for read, write and execute
  • Each UNIX process runs with the permissions of an OS user and his groups
  • The web server is a UNIX process
  • PHP usually runs as part of the web server
  • DokuWiki will run with the permissions of the PHP processor
  • DokuWiki needs read, write and execute permissions for directories it needs to create files in
  • DokuWiki needs read and write permissions for files it needs to write to
  • DokuWiki needs read only permissions for files and directories it doesn't need to write to
For more details on the permission setting see here .

Now once you are up and running with proper setting of php(yes,dokuwiki depend on php and should integrated with a web server.In out case we use Apache)

But until you configure your web server properly you won't be able to get the proper thing about this software. So let me share the Apache config related to this software:

1 # dokuwiki
2 # Standards compliant simple to use wiki
3 # 0
4 #
5 Alias /dokuwiki /var/www/html/dokuwiki
7 Options +FollowSymLinks
8 Order Allow,Deny
9 Allow from ::1

12 Order Deny,Allow
13 Deny from all

16 Order Deny,Allow
17 Deny from all

20 ## no access to the fla directory
21 Order allow,deny
22 Deny from all

25 Order Deny,Allow
26 Deny from all


So name it as dokuwiki.conf and put it in the /etc/apache| httpd/conf.d/

Restart the Apache to and go to the browser to get the start page by visiting the url mentioned above.

The dokuwiki file structure under the /etc looks like below:

bhaskar@bhaskar-laptop_17:37:34_Thu Oct 14:/etc/dokuwiki> ls
acl.auth.php dokuwiki.php interwiki.conf local.php mime.conf scheme.conf users.auth.php words.aspell
acronyms.conf entities.conf license.php mediameta.php msg smileys.conf wordblock.conf

Here it looks like on my system as I have created many pages with documentation,

Dokuwiki :

Now it is blessed with ACL(Access Control List),so you can tighten the grip on web space file permission.

bhaskar@bhaskar-laptop_17:37:34_Thu Oct 14:/etc/dokuwiki> sudo getfacl /var/www/html/dokuwiki/
[sudo] password for bhaskar:
getfacl: Removing leading '/' from absolute path names
# file: var/www/html/dokuwiki/
# owner: root
# group: root

Now the files might have different permission for your case.

To create a page you have click on the start hyperlink and it will provide you an empty page. On that page you have to click on the "create page" button to start working on it.

Dokuwiki has it's own syntax to work with and is very easy to implement.Kindly glean over it's syntax page for details.

Hope this will give you a fair idea how it works.If possible I might update this page later time with more details.


Wednesday, October 6, 2010

Open Source Software Licenses

In this article we are going to talk about the open system/open source software licenses.As most of you are aware(if not please read and understand)how those licenses intend to do then apply them as you like.So lets meet those licenses that made an impact on open source development.Being an GNU/Linux consultant my one of the prime job to explain the licensing issue to my clients so they can understand what they adopt into their infrastructure.And as my second role as an GNU/Linux administrator I am very curious about the licensing factor to implements something into the production base.So what I will suggest please give yourself sometime and go through the below mentioned licenses to accustomed yourself better for deployment.

Before we start one must know that Linux kernel is abide with GPL v.2 ,means all the codes are released under this license.

Free Document License:

GNU Free Documentation License
Version 1.2, November 2002

Copyright (C) 2000,2001,2002 Free Software Foundation, Inc.
51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
Everyone is permitted to copy and distribute verbatim copies
of this license document, but changing it is not allowed.


The purpose of this License is to make a manual, textbook, or other
functional and useful document "free" in the sense of freedom: to
assure everyone the effective freedom to copy and redistribute it,
with or without modifying it, either commercially or noncommercially.
Secondarily, this License preserves for the author and publisher a way
to get credit for their work, while not being considered responsible
for modifications made by others.

This License is a kind of "copyleft", which means that derivative
works of the document must themselves be free in the same sense. It
complements the GNU General Public License, which is a copyleft
license designed for free software.

We have designed this License in order to use it for manuals for free
software, because free software needs free documentation: a free
program should come with manuals providing the same freedoms that the
software does. But this License is not limited to software manuals;
it can be used for any textual work, regardless of subject matter or
whether it is published as a printed book. We recommend this License
principally for works whose purpose is instruction or reference.


This License applies to any manual or other work, in any medium, that
contains a notice placed by the copyright holder saying it can be
distributed under the terms of this License. Such a notice grants a
world-wide, royalty-free license, unlimited in duration, to use that
work under the conditions stated herein. The "Document", below,
refers to any such manual or work. Any member of the public is a
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A "Modified Version" of the Document means any work containing the
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If the Cover Text requirement of section 3 is applicable to these
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Translation is considered a kind of modification, so you may
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Replacing Invariant Sections with translations requires special
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the translation and the original version of this License or a notice
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If a section in the Document is Entitled "Acknowledgements",
"Dedications", or "History", the requirement (section 4) to Preserve
its Title (section 1) will typically require changing the actual


You may not copy, modify, sublicense, or distribute the Document except
as expressly provided for under this License. Any other attempt to
copy, modify, sublicense or distribute the Document is void, and will
automatically terminate your rights under this License. However,
parties who have received copies, or rights, from you under this
License will not have their licenses terminated so long as such
parties remain in full compliance.


The Free Software Foundation may publish new, revised versions
of the GNU Free Documentation License from time to time. Such new
versions will be similar in spirit to the present version, but may
differ in detail to address new problems or concerns. See

Each version of the License is given a distinguishing version number.
If the Document specifies that a particular numbered version of this
License "or any later version" applies to it, you have the option of
following the terms and conditions either of that specified version or
of any later version that has been published (not as a draft) by the
Free Software Foundation. If the Document does not specify a version
number of this License, you may choose any version ever published (not
as a draft) by the Free Software Foundation.

ADDENDUM: How to use this License for your documents

To use this License in a document you have written, include a copy of
the License in the document and put the following copyright and
license notices just after the title page:

Copyright (c) YEAR YOUR NAME.
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.2
or any later version published by the Free Software Foundation;
with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
A copy of the license is included in the section entitled "GNU
Free Documentation License".

If you have Invariant Sections, Front-Cover Texts and Back-Cover Texts,
replace the "with...Texts." line with this:

with the Invariant Sections being LIST THEIR TITLES, with the
Front-Cover Texts being LIST, and with the Back-Cover Texts being LIST.

If you have Invariant Sections without Cover Texts, or some other
combination of the three, merge those two alternatives to suit the

If your document contains nontrivial examples of program code, we
recommend releasing these examples in parallel under your choice of
free software license, such as the GNU General Public License,to permit their use in free software.

GPL a.k.a General Public License:

Version 3, 29 June 2007

Copyright (C) 2007 Free Software Foundation, Inc. «»
Everyone is permitted to copy and distribute verbatim copies
of this license document, but changing it is not allowed.


The GNU General Public License is a free, copyleft license for
software and other kinds of works.

The licenses for most software and other practical works are designed
to take away your freedom to share and change the works. By contrast,
the GNU General Public License is intended to guarantee your freedom to
share and change all versions of a program--to make sure it remains free
software for all its users. We, the Free Software Foundation, use the
GNU General Public License for most of our software; it applies also to
any other work released this way by its authors. You can apply it to
your programs, too.

When we speak of free software, we are referring to freedom, not
price. Our General Public Licenses are designed to make sure that you
have the freedom to distribute copies of free software (and charge for
them if you wish), that you receive source code or can get it if you
want it, that you can change the software or use pieces of it in new
free programs, and that you know you can do these things.

To protect your rights, we need to prevent others from denying you
these rights or asking you to surrender the rights. Therefore, you have
certain responsibilities if you distribute copies of the software, or if
you modify it: responsibilities to respect the freedom of others.

For example, if you distribute copies of such a program, whether
gratis or for a fee, you must pass on to the recipients the same
freedoms that you received. You must make sure that they, too, receive
or can get the source code. And you must show them these terms so they
know their rights.

Developers that use the GNU GPL protect your rights with two steps:
(1) assert copyright on the software, and (2) offer you this License
giving you legal permission to copy, distribute and/or modify it.

For the developers' and authors' protection, the GPL clearly explains
that there is no warranty for this free software. For both users' and
authors' sake, the GPL requires that modified versions be marked as
changed, so that their problems will not be attributed erroneously to
authors of previous versions.

Some devices are designed to deny users access to install or run
modified versions of the software inside them, although the manufacturer
can do so. This is fundamentally incompatible with the aim of
protecting users' freedom to change the software. The systematic
pattern of such abuse occurs in the area of products for individuals to
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have designed this version of the GPL to prohibit the practice for those
products. If such problems arise substantially in other domains, we
stand ready to extend this provision to those domains in future versions
of the GPL, as needed to protect the freedom of users.

Finally, every program is threatened constantly by software patents.
States should not allow patents to restrict development and use of
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avoid the special danger that patents applied to a free program could
make it effectively proprietary. To prevent this, the GPL assures that
patents cannot be used to render the program non-free.

The precise terms and conditions for copying, distribution and
modification follow.


0. Definitions.

"This License" refers to version 3 of the GNU General Public License.

"Copyright" also means copyright-like laws that apply to other kinds of
works, such as semiconductor masks.

"The Program" refers to any copyrightable work licensed under this
License. Each licensee is addressed as "you". "Licensees" and
"recipients" may be individuals or organizations.

To "modify" a work means to copy from or adapt all or part of the work
in a fashion requiring copyright permission, other than the making of an
exact copy. The resulting work is called a "modified version" of the
earlier work or a work "based on" the earlier work.

A "covered work" means either the unmodified Program or a work based
on the Program.

To "propagate" a work means to do anything with it that, without
permission, would make you directly or secondarily liable for
infringement under applicable copyright law, except executing it on a
computer or modifying a private copy. Propagation includes copying,
distribution (with or without modification), making available to the
public, and in some countries other activities as well.

To "convey" a work means any kind of propagation that enables other
parties to make or receive copies. Mere interaction with a user through
a computer network, with no transfer of a copy, is not conveying.

An interactive user interface displays "Appropriate Legal Notices"
to the extent that it includes a convenient and prominently visible
feature that (1) displays an appropriate copyright notice, and (2)
tells the user that there is no warranty for the work (except to the
extent that warranties are provided), that licensees may convey the
work under this License, and how to view a copy of this License. If
the interface presents a list of user commands or options, such as a
menu, a prominent item in the list meets this criterion.

1. Source Code.

The "source code" for a work means the preferred form of the work
for making modifications to it. "Object code" means any non-source
form of a work.

A "Standard Interface" means an interface that either is an official
standard defined by a recognized standards body, or, in the case of
interfaces specified for a particular programming language, one that
is widely used among developers working in that language.

The "System Libraries" of an executable work include anything, other
than the work as a whole, that (a) is included in the normal form of
packaging a Major Component, but which is not part of that Major
Component, and (b) serves only to enable use of the work with that
Major Component, or to implement a Standard Interface for which an
implementation is available to the public in source code form. A
"Major Component", in this context, means a major essential component
(kernel, window system, and so on) of the specific operating system
(if any) on which the executable work runs, or a compiler used to
produce the work, or an object code interpreter used to run it.

The "Corresponding Source" for a work in object code form means all
the source code needed to generate, install, and (for an executable
work) run the object code and to modify the work, including scripts to
control those activities. However, it does not include the work's
System Libraries, or general-purpose tools or generally available free
programs which are used unmodified in performing those activities but
which are not part of the work. For example, Corresponding Source
includes interface definition files associated with source files for
the work, and the source code for shared libraries and dynamically
linked subprograms that the work is specifically designed to require,
such as by intimate data communication or control flow between those
subprograms and other parts of the work.

The Corresponding Source need not include anything that users
can regenerate automatically from other parts of the Corresponding

The Corresponding Source for a work in source code form is that
same work.

2. Basic Permissions.

All rights granted under this License are granted for the term of
copyright on the Program, and are irrevocable provided the stated
conditions are met. This License explicitly affirms your unlimited
permission to run the unmodified Program. The output from running a
covered work is covered by this License only if the output, given its
content, constitutes a covered work. This License acknowledges your
rights of fair use or other equivalent, as provided by copyright law.

You may make, run and propagate covered works that you do not
convey, without conditions so long as your license otherwise remains
in force. You may convey covered works to others for the sole purpose
of having them make modifications exclusively for you, or provide you
with facilities for running those works, provided that you comply with
the terms of this License in conveying all material for which you do
not control copyright. Those thus making or running the covered works
for you must do so exclusively on your behalf, under your direction
and control, on terms that prohibit them from making any copies of
your copyrighted material outside their relationship with you.

Conveying under any other circumstances is permitted solely under
the conditions stated below. Sublicensing is not allowed; section 10
makes it unnecessary.

3. Protecting Users' Legal Rights From Anti-Circumvention Law.

No covered work shall be deemed part of an effective technological
measure under any applicable law fulfilling obligations under article
11 of the WIPO copyright treaty adopted on 20 December 1996, or
similar laws prohibiting or restricting circumvention of such

When you convey a covered work, you waive any legal power to forbid
circumvention of technological measures to the extent such circumvention
is effected by exercising rights under this License with respect to
the covered work, and you disclaim any intention to limit operation or
modification of the work as a means of enforcing, against the work's
users, your or third parties' legal rights to forbid circumvention of
technological measures.

4. Conveying Verbatim Copies.

You may convey verbatim copies of the Program's source code as you
receive it, in any medium, provided that you conspicuously and
appropriately publish on each copy an appropriate copyright notice;
keep intact all notices stating that this License and any
non-permissive terms added in accord with section 7 apply to the code;
keep intact all notices of the absence of any warranty; and give all
recipients a copy of this License along with the Program.

You may charge any price or no price for each copy that you convey,
and you may offer support or warranty protection for a fee.

5. Conveying Modified Source Versions.

You may convey a work based on the Program, or the modifications to
produce it from the Program, in the form of source code under the
terms of section 4, provided that you also meet all of these conditions:

a) The work must carry prominent notices stating that you modified
it, and giving a relevant date.

b) The work must carry prominent notices stating that it is
released under this License and any conditions added under section
7. This requirement modifies the requirement in section 4 to
"keep intact all notices".

c) You must license the entire work, as a whole, under this
License to anyone who comes into possession of a copy. This
License will therefore apply, along with any applicable section 7
additional terms, to the whole of the work, and all its parts,
regardless of how they are packaged. This License gives no
permission to license the work in any other way, but it does not
invalidate such permission if you have separately received it.

d) If the work has interactive user interfaces, each must display
Appropriate Legal Notices; however, if the Program has interactive
interfaces that do not display Appropriate Legal Notices, your
work need not make them do so.

A compilation of a covered work with other separate and independent
works, which are not by their nature extensions of the covered work,
and which are not combined with it such as to form a larger program,
in or on a volume of a storage or distribution medium, is called an
"aggregate" if the compilation and its resulting copyright are not
used to limit the access or legal rights of the compilation's users
beyond what the individual works permit. Inclusion of a covered work
in an aggregate does not cause this License to apply to the other
parts of the aggregate.

6. Conveying Non-Source Forms.

You may convey a covered work in object code form under the terms
of sections 4 and 5, provided that you also convey the
machine-readable Corresponding Source under the terms of this License,
in one of these ways:

a) Convey the object code in, or embodied in, a physical product
(including a physical distribution medium), accompanied by the
Corresponding Source fixed on a durable physical medium
customarily used for software interchange.

b) Convey the object code in, or embodied in, a physical product
(including a physical distribution medium), accompanied by a
written offer, valid for at least three years and valid for as
long as you offer spare parts or customer support for that product
model, to give anyone who possesses the object code either (1) a
copy of the Corresponding Source for all the software in the
product that is covered by this License, on a durable physical
medium customarily used for software interchange, for a price no
more than your reasonable cost of physically performing this
conveying of source, or (2) access to copy the
Corresponding Source from a network server at no charge.

c) Convey individual copies of the object code with a copy of the
written offer to provide the Corresponding Source. This
alternative is allowed only occasionally and noncommercially, and
only if you received the object code with such an offer, in accord
with subsection 6b.

d) Convey the object code by offering access from a designated
place (gratis or for a charge), and offer equivalent access to the
Corresponding Source in the same way through the same place at no
further charge. You need not require recipients to copy the
Corresponding Source along with the object code. If the place to
copy the object code is a network server, the Corresponding Source
may be on a different server (operated by you or a third party)
that supports equivalent copying facilities, provided you maintain
clear directions next to the object code saying where to find the
Corresponding Source. Regardless of what server hosts the
Corresponding Source, you remain obligated to ensure that it is
available for as long as needed to satisfy these requirements.

e) Convey the object code using peer-to-peer transmission, provided
you inform other peers where the object code and Corresponding
Source of the work are being offered to the general public at no
charge under subsection 6d.

A separable portion of the object code, whose source code is excluded
from the Corresponding Source as a System Library, need not be
included in conveying the object code work.

A "User Product" is either (1) a "consumer product", which means any
tangible personal property which is normally used for personal, family,
or household purposes, or (2) anything designed or sold for incorporation
into a dwelling. In determining whether a product is a consumer product,
doubtful cases shall be resolved in favor of coverage. For a particular
product received by a particular user, "normally used" refers to a
typical or common use of that class of product, regardless of the status
of the particular user or of the way in which the particular user
actually uses, or expects or is expected to use, the product. A product
is a consumer product regardless of whether the product has substantial
commercial, industrial or non-consumer uses, unless such uses represent
the only significant mode of use of the product.

"Installation Information" for a User Product means any methods,
procedures, authorization keys, or other information required to install
and execute modified versions of a covered work in that User Product from
a modified version of its Corresponding Source. The information must
suffice to ensure that the continued functioning of the modified object
code is in no case prevented or interfered with solely because
modification has been made.

If you convey an object code work under this section in, or with, or
specifically for use in, a User Product, and the conveying occurs as
part of a transaction in which the right of possession and use of the
User Product is transferred to the recipient in perpetuity or for a
fixed term (regardless of how the transaction is characterized), the
Corresponding Source conveyed under this section must be accompanied
by the Installation Information. But this requirement does not apply
if neither you nor any third party retains the ability to install
modified object code on the User Product (for example, the work has
been installed in ROM).

The requirement to provide Installation Information does not include a
requirement to continue to provide support service, warranty, or updates
for a work that has been modified or installed by the recipient, or for
the User Product in which it has been modified or installed. Access to a
network may be denied when the modification itself materially and
adversely affects the operation of the network or violates the rules and
protocols for communication across the network.

Corresponding Source conveyed, and Installation Information provided,
in accord with this section must be in a format that is publicly
documented (and with an implementation available to the public in
source code form), and must require no special password or key for
unpacking, reading or copying.

7. Additional Terms.

"Additional permissions" are terms that supplement the terms of this
License by making exceptions from one or more of its conditions.
Additional permissions that are applicable to the entire Program shall
be treated as though they were included in this License, to the extent
that they are valid under applicable law. If additional permissions
apply only to part of the Program, that part may be used separately
under those permissions, but the entire Program remains governed by
this License without regard to the additional permissions.

When you convey a copy of a covered work, you may at your option
remove any additional permissions from that copy, or from any part of
it. (Additional permissions may be written to require their own
removal in certain cases when you modify the work.) You may place
additional permissions on material, added by you to a covered work,
for which you have or can give appropriate copyright permission.

Notwithstanding any other provision of this License, for material you
add to a covered work, you may (if authorized by the copyright holders of
that material) supplement the terms of this License with terms:

a) Disclaiming warranty or limiting liability differently from the
terms of sections 15 and 16 of this License; or

b) Requiring preservation of specified reasonable legal notices or
author attributions in that material or in the Appropriate Legal
Notices displayed by works containing it; or

c) Prohibiting misrepresentation of the origin of that material, or
requiring that modified versions of such material be marked in
reasonable ways as different from the original version; or

d) Limiting the use for publicity purposes of names of licensors or
authors of the material; or

e) Declining to grant rights under trademark law for use of some
trade names, trademarks, or service marks; or

f) Requiring indemnification of licensors and authors of that
material by anyone who conveys the material (or modified versions of
it) with contractual assumptions of liability to the recipient, for
any liability that these contractual assumptions directly impose on
those licensors and authors.

All other non-permissive additional terms are considered "further
restrictions" within the meaning of section 10. If the Program as you
received it, or any part of it, contains a notice stating that it is
governed by this License along with a term that is a further
restriction, you may remove that term. If a license document contains
a further restriction but permits relicensing or conveying under this
License, you may add to a covered work material governed by the terms
of that license document, provided that the further restriction does
not survive such relicensing or conveying.

If you add terms to a covered work in accord with this section, you
must place, in the relevant source files, a statement of the
additional terms that apply to those files, or a notice indicating
where to find the applicable terms.

Additional terms, permissive or non-permissive, may be stated in the
form of a separately written license, or stated as exceptions;
the above requirements apply either way.

8. Termination.

You may not propagate or modify a covered work except as expressly
provided under this License. Any attempt otherwise to propagate or
modify it is void, and will automatically terminate your rights under
this License (including any patent licenses granted under the third
paragraph of section 11).

However, if you cease all violation of this License, then your
license from a particular copyright holder is reinstated (a)
provisionally, unless and until the copyright holder explicitly and
finally terminates your license, and (b) permanently, if the copyright
holder fails to notify you of the violation by some reasonable means
prior to 60 days after the cessation.

Moreover, your license from a particular copyright holder is
reinstated permanently if the copyright holder notifies you of the
violation by some reasonable means, this is the first time you have
received notice of violation of this License (for any work) from that
copyright holder, and you cure the violation prior to 30 days after
your receipt of the notice.

Termination of your rights under this section does not terminate the
licenses of parties who have received copies or rights from you under
this License. If your rights have been terminated and not permanently
reinstated, you do not qualify to receive new licenses for the same
material under section 10.

9. Acceptance Not Required for Having Copies.

You are not required to accept this License in order to receive or
run a copy of the Program. Ancillary propagation of a covered work
occurring solely as a consequence of using peer-to-peer transmission
to receive a copy likewise does not require acceptance. However,
nothing other than this License grants you permission to propagate or
modify any covered work. These actions infringe copyright if you do
not accept this License. Therefore, by modifying or propagating a
covered work, you indicate your acceptance of this License to do so.

10. Automatic Licensing of Downstream Recipients.

Each time you convey a covered work, the recipient automatically
receives a license from the original licensors, to run, modify and
propagate that work, subject to this License. You are not responsible
for enforcing compliance by third parties with this License.

An "entity transaction" is a transaction transferring control of an
organization, or substantially all assets of one, or subdividing an
organization, or merging organizations. If propagation of a covered
work results from an entity transaction, each party to that
transaction who receives a copy of the work also receives whatever
licenses to the work the party's predecessor in interest had or could
give under the previous paragraph, plus a right to possession of the
Corresponding Source of the work from the predecessor in interest, if
the predecessor has it or can get it with reasonable efforts.

You may not impose any further restrictions on the exercise of the
rights granted or affirmed under this License. For example, you may
not impose a license fee, royalty, or other charge for exercise of
rights granted under this License, and you may not initiate litigation
(including a cross-claim or counterclaim in a lawsuit) alleging that
any patent claim is infringed by making, using, selling, offering for
sale, or importing the Program or any portion of it.

11. Patents.

A "contributor" is a copyright holder who authorizes use under this
License of the Program or a work on which the Program is based. The
work thus licensed is called the contributor's "contributor version".

A contributor's "essential patent claims" are all patent claims
owned or controlled by the contributor, whether already acquired or
hereafter acquired, that would be infringed by some manner, permitted
by this License, of making, using, or selling its contributor version,
but do not include claims that would be infringed only as a
consequence of further modification of the contributor version. For
purposes of this definition, "control" includes the right to grant
patent sublicenses in a manner consistent with the requirements of
this License.

Each contributor grants you a non-exclusive, worldwide, royalty-free
patent license under the contributor's essential patent claims, to
make, use, sell, offer for sale, import and otherwise run, modify and
propagate the contents of its contributor version.

In the following three paragraphs, a "patent license" is any express
agreement or commitment, however denominated, not to enforce a patent
(such as an express permission to practice a patent or covenant not to
sue for patent infringement). To "grant" such a patent license to a
party means to make such an agreement or commitment not to enforce a
patent against the party.

If you convey a covered work, knowingly relying on a patent license,
and the Corresponding Source of the work is not available for anyone
to copy, free of charge and under the terms of this License, through a
publicly available network server or other readily accessible means,
then you must either (1) cause the Corresponding Source to be so
available, or (2) arrange to deprive yourself of the benefit of the
patent license for this particular work, or (3) arrange, in a manner
consistent with the requirements of this License, to extend the patent
license to downstream recipients. "Knowingly relying" means you have
actual knowledge that, but for the patent license, your conveying the
covered work in a country, or your recipient's use of the covered work
in a country, would infringe one or more identifiable patents in that
country that you have reason to believe are valid.

If, pursuant to or in connection with a single transaction or
arrangement, you convey, or propagate by procuring conveyance of, a
covered work, and grant a patent license to some of the parties
receiving the covered work authorizing them to use, propagate, modify
or convey a specific copy of the covered work, then the patent license
you grant is automatically extended to all recipients of the covered
work and works based on it.

A patent license is "discriminatory" if it does not include within
the scope of its coverage, prohibits the exercise of, or is
conditioned on the non-exercise of one or more of the rights that are
specifically granted under this License. You may not convey a covered
work if you are a party to an arrangement with a third party that is
in the business of distributing software, under which you make payment
to the third party based on the extent of your activity of conveying
the work, and under which the third party grants, to any of the
parties who would receive the covered work from you, a discriminatory
patent license (a) in connection with copies of the covered work
conveyed by you (or copies made from those copies), or (b) primarily
for and in connection with specific products or compilations that
contain the covered work, unless you entered into that arrangement,
or that patent license was granted, prior to 28 March 2007.

Nothing in this License shall be construed as excluding or limiting
any implied license or other defenses to infringement that may
otherwise be available to you under applicable patent law.

12. No Surrender of Others' Freedom.

If conditions are imposed on you (whether by court order, agreement or
otherwise) that contradict the conditions of this License, they do not
excuse you from the conditions of this License. If you cannot convey a
covered work so as to satisfy simultaneously your obligations under this
License and any other pertinent obligations, then as a consequence you may
not convey it at all. For example, if you agree to terms that obligate you
to collect a royalty for further conveying from those to whom you convey
the Program, the only way you could satisfy both those terms and this
License would be to refrain entirely from conveying the Program.

13. Use with the GNU Affero General Public License.

Notwithstanding any other provision of this License, you have
permission to link or combine any covered work with a work licensed
under version 3 of the GNU Affero General Public License into a single
combined work, and to convey the resulting work. The terms of this
License will continue to apply to the part which is the covered work,
but the special requirements of the GNU Affero General Public License,
section 13, concerning interaction through a network will apply to the
combination as such.

14. Revised Versions of this License.

The Free Software Foundation may publish revised and/or new versions of
the GNU General Public License from time to time. Such new versions will
be similar in spirit to the present version, but may differ in detail to
address new problems or concerns.

Each version is given a distinguishing version number. If the
Program specifies that a certain numbered version of the GNU General
Public License "or any later version" applies to it, you have the
option of following the terms and conditions either of that numbered
version or of any later version published by the Free Software
Foundation. If the Program does not specify a version number of the
GNU General Public License, you may choose any version ever published
by the Free Software Foundation.

If the Program specifies that a proxy can decide which future
versions of the GNU General Public License can be used, that proxy's
public statement of acceptance of a version permanently authorizes you
to choose that version for the Program.

Later license versions may give you additional or different
permissions. However, no additional obligations are imposed on any
author or copyright holder as a result of your choosing to follow a
later version.

15. Disclaimer of Warranty.


16. Limitation of Liability.


17. Interpretation of Sections 15 and 16.

If the disclaimer of warranty and limitation of liability provided
above cannot be given local legal effect according to their terms,
reviewing courts shall apply local law that most closely approximates
an absolute waiver of all civil liability in connection with the
Program, unless a warranty or assumption of liability accompanies a
copy of the Program in return for a fee.


How to Apply These Terms to Your New Programs

If you develop a new program, and you want it to be of the greatest
possible use to the public, the best way to achieve this is to make it
free software which everyone can redistribute and change under these terms.

To do so, attach the following notices to the program. It is safest
to attach them to the start of each source file to most effectively
state the exclusion of warranty; and each file should have at least
the "copyright" line and a pointer to where the full notice is found.

«one line to give the program's name and a brief idea of what it does.»
Copyright (C) «year» «name of author»

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program. If not, see «».

Also add information on how to contact you by electronic and paper mail.

If the program does terminal interaction, make it output a short
notice like this when it starts in an interactive mode:

«program» Copyright (C) «year» «name of author»
This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
This is free software, and you are welcome to redistribute it
under certain conditions; type `show c' for details.

The hypothetical commands `show w' and `show c' should show the appropriate
parts of the General Public License. Of course, your program's commands
might be different; for a GUI interface, you would use an "about box".

You should also get your employer (if you work as a programmer) or school,
if any, to sign a "copyright disclaimer" for the program, if necessary.
For more information on this, and how to apply and follow the GNU GPL, see

The GNU General Public License does not permit incorporating your program
into proprietary programs. If your program is a subroutine library, you
may consider it more useful to permit linking proprietary applications with
the library. If this is what you want to do, use the GNU Lesser General
Public License instead of this License. But first, please read

LPGL a.k.a Lesser General Public License:

Version 3, 29 June 2007

Copyright (C) 2007 Free Software Foundation, Inc. «»
Everyone is permitted to copy and distribute verbatim copies
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This version of the GNU Lesser General Public License incorporates
the terms and conditions of version 3 of the GNU General Public
License, supplemented by the additional permissions listed below.

0. Additional Definitions.

As used herein, "this License" refers to version 3 of the GNU Lesser
General Public License, and the "GNU GPL" refers to version 3 of the GNU
General Public License.

"The Library" refers to a covered work governed by this License,
other than an Application or a Combined Work as defined below.

An "Application" is any work that makes use of an interface provided
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and utility programs needed for reproducing the Combined Work from the
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1. Exception to Section 3 of the GNU GPL.

You may convey a covered work under sections 3 and 4 of this License
without being bound by section 3 of the GNU GPL.

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b) under the GNU GPL, with none of the additional permissions of
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The object code form of an Application may incorporate material from
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b) Accompany the object code with a copy of the GNU GPL and this license

4. Combined Works.

You may convey a Combined Work under terms of your choice that,
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b) Accompany the Combined Work with a copy of the GNU GPL and this license

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0) Convey the Minimal Corresponding Source under the terms of this
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a) Accompany the combined library with a copy of the same work based
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b) Give prominent notice with the combined library that part of it
is a work based on the Library, and explaining where to find the
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6. Revised Versions of the GNU Lesser General Public License.

The Free Software Foundation may publish revised and/or new versions
of the GNU Lesser General Public License from time to time. Such new
versions will be similar in spirit to the present version, but may
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Each version is given a distinguishing version number. If the
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Apache License:

Apache License, Version 2.0

Apache License
Version 2.0, January 2004


1. Definitions.

"License" shall mean the terms and conditions for use, reproduction, and distribution as defined by Sections 1 through 9 of this document.

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"You" (or "Your") shall mean an individual or Legal Entity exercising permissions granted by this License.

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"Work" shall mean the work of authorship, whether in Source or Object form, made available under the License, as indicated by a copyright notice that is included in or attached to the work (an example is provided in the Appendix below).

"Derivative Works" shall mean any work, whether in Source or Object form, that is based on (or derived from) the Work and for which the editorial revisions, annotations, elaborations, or other modifications represent, as a whole, an original work of authorship. For the purposes of this License, Derivative Works shall not include works that remain separable from, or merely link (or bind by name) to the interfaces of, the Work and Derivative Works thereof.

"Contribution" shall mean any work of authorship, including the original version of the Work and any modifications or additions to that Work or Derivative Works thereof, that is intentionally submitted to Licensor for inclusion in the Work by the copyright owner or by an individual or Legal Entity authorized to submit on behalf of the copyright owner. For the purposes of this definition, "submitted" means any form of electronic, verbal, or written communication sent to the Licensor or its representatives, including but not limited to communication on electronic mailing lists, source code control systems, and issue tracking systems that are managed by, or on behalf of, the Licensor for the purpose of discussing and improving the Work, but excluding communication that is conspicuously marked or otherwise designated in writing by the copyright owner as "Not a Contribution."

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You may add Your own copyright statement to Your modifications and may provide additional or different license terms and conditions for use, reproduction, or distribution of Your modifications, or for any such Derivative Works as a whole, provided Your use, reproduction, and distribution of the Work otherwise complies with the conditions stated in this License.

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8. Limitation of Liability. In no event and under no legal theory, whether in tort (including negligence), contract, or otherwise, unless required by applicable law (such as deliberate and grossly negligent acts) or agreed to in writing, shall any Contributor be liable to You for damages, including any direct, indirect, special, incidental, or consequential damages of any character arising as a result of this License or out of the use or inability to use the Work (including but not limited to damages for loss of goodwill, work stoppage, computer failure or malfunction, or any and all other commercial damages or losses), even if such Contributor has been advised of the possibility of such damages.

9. Accepting Warranty or Additional Liability. While redistributing the Work or Derivative Works thereof, You may choose to offer, and charge a fee for, acceptance of support, warranty, indemnity, or other liability obligations and/or rights consistent with this License. However, in accepting such obligations, You may act only on Your own behalf and on Your sole responsibility, not on behalf of any other Contributor, and only if You agree to indemnify, defend, and hold each Contributor harmless for any liability incurred by, or claims asserted against, such Contributor by reason of your accepting any such warranty or additional liability.

APPENDIX: How to apply the Apache License to your work

To apply the Apache License to your work, attach the following boilerplate notice, with the fields enclosed by brackets "[]" replaced with your own identifying information. (Don't include the brackets!) The text should be enclosed in the appropriate comment syntax for the file format. We also recommend that a file or class name and description of purpose be included on the same "printed page" as the copyright notice for easier identification within third-party archives.
Copyright [yyyy] [name of copyright owner] Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

Creative Commons License:

The below section is excerpted from Aditya's Blog .

Creative Commons provide an out of the box license which is not only flexible but also easy to use and much more easier than create. Yes, you can create a CC license, specially customized to suit your needs like the one I have for this blog. You can create a license for your work here. CC license is not generally used for software licensing. It is more suited for literature or documentation work. In this license type you can choose the condition you want to set for your work. These conditions are :-

1. Attribution : You let others to copy and use your work only if they give you the credit the way you want.
2. Share Alike : You can allow other users to share your work but keeping the same or similsr license like the original one.
3. Noncommercial : You can permit others to use your work for Noncommercial/Commercial purposes
4. No Derivative Works : You give others permission to copy and distribute your work. But only Verbatim copies not any sort of derived work.

Just glean over this url CC-url

Moreover if you really want know more about it then please visit GNU website for the infomation regarding license.

Hope this will help.