SVN (Subversion) Commands

subversion by apache

What is SVN (Subversion)?

Apache Subversion (often abbreviated SVN, after the command name svn) is a software versioning and revision control system distributed under an open source license. Developers use Subversion to maintain current and historical versions of files such as source code, web pages, and documentation. Its goal is to be a mostly compatible successor to the widely used Concurrent Versions System (CVS).

The open source community has used Subversion widely: for example in projects such as Apache Software Foundation, Free Pascal, FreeBSD, GCC, Mono and SourceForge. Google Code also provides Subversion hosting for their open source projects. BountySource systems use it exclusively. CodePlex offers access to Subversion as well as to other types of clients.

The corporate world has also started to adopt Subversion. A 2007 report by Forrester Research recognized Subversion as the sole leader in the Standalone Software Configuration Management (SCM) category and as a strong performer in the Software Configuration and Change Management (SCCM) category.[1]

Subversion was created by CollabNet Inc. in 2000 and is now a top-level Apache project being built and used by a global community of contributors.

Some of the commands frequently used related to SVN is listed below.

* Create Svn Repository

Syntax: svnadmin create <svn data directory><$repository_name>


  $ svnadmin create /var/www/svn/repotest

-Command to create a repository using the default configuration.

$ chown apache.apache /var/www/svn/repotest 

– Command to use after creating the repository to assign ownership of the repository root directory to apache.


Syntax: svnadmin create –fs-type fsfs <svn data directory><$repository_name>

  $ svnadmin create --fs-type fsfs /var/www/svn/repotest

-Command to create a repository using specifying the repository type.

$ chown apache.apache /var/www/svn/repotest 

– Command to use after creating the repository to assign ownership of the repository root directory to apache.

  * Initially input repo data to repository

$ svn import -m "Initial import." /var/www/svn/repotest/ file:///var/www/svn/myrepo

– where /var/www/svn/repotest is the root directory of the repository and file:///var/www/svn/repotest will be the online repository directory

  * list and view contents of a repo in tree view

Syntax: svnlook tree <repository absolute path>

  $ svnlook tree /var/www/svn/repotest/ 

  * View SVN Information

$ svn info

  * List down all repo

$ svn st

  * Add to svn a file or folder

$ svn add <file>

  * Create a Directory for svn

$ svn mkdir <directory>

 * Log svn

$ svn log

  *To revert to original file

$  svn revert <path>

  - revert a whole directory of files, use the --depth=infinity option:

$ svn revert --depth=infinity <path>


  *Delete a file or directory from svn

$ svn delete <directory>

  *Commit all changes made to file (Note: must be inside the repository path

$ svn ci -m "adding directories"

– Where ci is the commit command and -m is the parameter for the additional message and “adding directories” would be the notes included for the commit .

If you want to use a file that’s under version control for your commit message with --file, you need to pass the --force-log s witch:

$ svn commit --file file_under_vc.txt foo.c
svn: The log message file is under version control
svn: Log message file is a versioned file; use '--force-log' to override

$ svn commit --force-log --file file_under_vc.txt foo.c
Sending        foo.c
Transmitting file data .
Committed revision 6.

  *Checkout contents of Repository/get files and details

Syntax: svn co <repository_site> <path>

$ svn co  /var/www/svn/repotest/ 

For more commands on SVN Click here.

Happy versioning.

How to install APC (Alternative php cache)

Definition: The Alternative PHP Cache (APC) is a free and open opcode cache for PHP. Its goal is to provide a free, open, and robust framework for caching and optimizing PHP intermediate code.

I am posting a quick step-by-step guide to install APC on servers (dedicated or VPS) with cpanel/whm working. This is for those who have a hard time installing apc.

First login as a root to your server/vps and make a directory to work with this plugin,

#mkdir /home/APC-php

#cd /home/APC-php

now here we will first download the APC with following command


you can check for the latest version

now you can use gzip and tar separately or tar -xzvf to unzip this file

#tar -xzvf APC-3.0.14.tgz

now you will have a APC-3.0.14 folder.

#cd APC-3.0.14

now you have to make php configuration files by following command


after this use following three commands

# ./configure –enable-apc –enable-apc-mmap –with-apxs –with-php-config=/usr/bin/php-config

*if you do not know the php path then execute ( which php ) command it will display the path. on a typical cpanel vps it could be /usr/bin/php-config or /usr/local/bin/php-config but you better check it before executing the above command)


#make test

#make install

NOTE: if you are using suPHP then skip –with-apxs

*one more thing, if you use

#make test

command it shows 3 tests failed then do not worry, it showed at least to me but worked with the final steps.

the (make install) command will return the module path, note down that with you as you will have to feed it in the php.ini file in the next step.

check your php.ini location by

#php -i | grep php.ini

then open it with your favorite editor. mine was at

#vi /usr/local/lib/php.ini

and go to the last line and paste the following


now there is a catch in it, if you have other modules installed and their extension directory is different than the one MAKE INSTALL showed for APC so you have to move your to that directory so that all modules are in the same directory. in my case my APC directory was


but i moved from this location to my other location where my other files were.

you can check that path in php.ini sectiion of

extension_dir = “”

after this restart your apache, for different servers it may vary mine worked with

#service httpd restart

CentOS 5.2 ModSecurity Installation

CentOS 5.2 ModSecurity Installation

While this guide is CentOS specific, it contains enough detail to be adaptable to most other distributions.

ModSecurity is essentially a firewall for Apache, it checks all traffic against a set of rules which detect and prevent potentially malicious activity. There are three parts to this ModSec installation.

1. ModSecurity
2. mlogc
3. ModSecurity Console

Modsecurity is the ‘firewall’, mlogc is responsible for sending logs to the management console.

The console can be downloaded from, I used the Windows version for simplicity. Each console installation can support multiple sensors (ModSec installations), so it provides centralised monitoring. The console installation isn’t covered here, theres nothing to it – download, install, create sensors – done. Just make sure to install a valid license (free ones which support upto 3 sensors are currently available from

Versions used:

Apache: 2.2.3
ModSecurity: 2.5.7

Install Dependencies:

yum install httpd-devel libxml2 libxml2-devel curl-devel pcre-devel gcc-c++

note: curl-devel is only required for mlogc

Download and Installation


or, get the latest from

Stop Apache

service httpd stop

Untar it and install:

tar -xvzf modsecurity-apache_2.5.7.tar.gz

cd modsecurity-apache_2.5.7/apache2/

make mlogc
make install


Configure mlogc:

Copy the binary from mlogc-src/ to /usr/local/bin/

cp mlogc-src/mlogc /usr/local/bin/

Copy the default config to /etc/

cp mlogc-src/mlogc-default.conf /etc/mlogc.conf

Edit the configuration file: /etc/mlogc.conf:

Change the following:

ConsoleURI https://CONSOLE_IP_ADDRESS:8886/rpc/auditLogReceiver

SensorUsername “SENSOR_USERNAME”
SensorPassword “SENSOR_PASSWORD”

The above values need to reflect the Console installation and sensor configuration, also ensure the port is correct, it should be either 8886 or 8888. Save and exit

Configure ModSecurity:

Edit httpd.conf and add the following

# ModSecurity

Include conf/modsecurity/*.conf
LoadFile /usr/lib/
LoadModule unique_id_module modules/
LoadModule security2_module modules/

Still in the httpd.conf, go down to the main server configuration section and add:

# ModSecurity Configuration

# Turn the filtering engine On or Off
SecFilterEngine On

# Make sure that URL encoding is valid
SecFilterCheckURLEncoding On

# Unicode encoding check
SecFilterCheckUnicodeEncoding Off

# Only allow bytes from this range
SecFilterForceByteRange 0 255

# Only log suspicious requests
SecAuditEngine RelevantOnly

# Debug level set to a minimum
SecFilterDebugLog logs/modsec_debug_log
SecFilterDebugLevel 0

# Should mod_security inspect POST payloads
SecFilterScanPOST On

# By default log and deny suspicious requests
# with HTTP status 500
SecFilterDefaultAction “deny,log,status:500”

# Use ReleventOnly auditing
SecAuditEngine RelevantOnly

# Must use concurrent logging
SecAuditLogType Concurrent

# Send all audit log parts
SecAuditLogParts ABIDEFGHZ

# Use the same /CollectorRoot/LogStorageDir as in mlogc.conf
SecAuditLogStorageDir /var/log/mlogc/data

# Pipe audit log to mlogc with your configuration
SecAuditLog “|/usr/local/bin/mlogc /etc/mlogc.conf”

Save and Exit.

Copy rules to Apache directory

mkdir /etc/httpd/conf/modsecurity

from the rules direcotry:

cp *.conf /etc/httpd/conf/modsecurity

make necessary changes to modsecurity_crs_10_config.conf (mainly the logging section – use values from httpd.conf)

# Log files structure

SecAuditLogType Concurrent
SecAuditLog “|/usr/local/bin/mlogc /etc/mlogc.conf”
SecAuditLogStorageDir /var/log/mlogc/data

SecAuditLogParts “ABIDEFGHZ”

Create mlogc logs direcotry and configure permissions

mkdir /var/log/mlogc
mkdir /var/log/mlogc/data

chown :apache /var/log/mlogc
chown :apache /var/log/mlogc/data

chmod g+w /var/log/mlogc
chmod g+w /var/log/mlogc/data

Restart Apache

service httpd start

Confirm ModSecurity is running:

tail /var/log/httpd/error_log

[Wed Oct 22 21:37:45 2008] [notice] ModSecurity for Apache/2.5.7 ( configured.
[Wed Oct 22 21:37:45 2008] [notice] Digest: generating secret for digest authentication …
[Wed Oct 22 21:37:45 2008] [notice] Digest: done
[Wed Oct 22 21:37:46 2008] [notice] Apache/2.2.3 (CentOS) configured — resuming normal operations

Done! Generate some suspicous traffic (ie. run an nmap scan against port 80) and check the console for alerts.

Files to check if things don’t work:


How to install json module of php in linux box


JSON, or JavaScript Object Notation, has been getting a large amount of attention recently in the IT world. This is mostly powered by its extremely lightweight implementation, its common usage in API responses, and its already native support in JavaScript. JSON isn’t simply a way to code objects in JavaScript, but it is the actual form that a JavaScript engine will map the object to in memory. In short, it is an extremely fast and powerful way of transporting data between two interfaces.


If you are encountering any weird stuff with your PHP-JSON module installation, you might want to reinstall JSON using this link, this might get rid of the bug that is pestering you and your application.

First, uninstall any previous JSON installation you have so as not to conflict with the new one. To make sure you got the old JSON out, check your list of PHP modules by running:

php -m

JSON should not be listed and make sure you do not see any errors either. Doing this will prevent further headaches, trust me.

Perform the following steps to install the bug-free version of JSON from source:

1. Download the JSON source from here. You can use wget to download the source if you are using CLI


2. Uncompress the archive and change directory.

tar jxf php-json-ext-1.2.1.tar.bz2
cd php-json-ext-1.2.1

3. Run phpize. Make sure that phpize is installed before proceeding to this step. phpize is included in the php-devel package.


4. Configure, make and make install

make install

JSON is now installed, but make sure that is loaded in your php.ini file.

1. Open php.ini file. If you are unsure about the location of your php.ini file, run

php -i | grep php.ini

You should see something like this:

Loaded Configuration File => /etc/php.ini

2. Add this at the last line of the configuration file:

3. You might want to restart Apache to make sure everything is still working.

To check if JSON is loaded as module, run php -m again, make sure JSON is in the list.

Now, to test JSON, open an editor and copy these lines:

Save the file (json-test.php is the filename in this case).

Execute the file by running php json-test.php

The result should be 12121211212121