I’m using Apache server in CentOS / RHEL / Debian / Ubuntu and I’d like to start, stop or restart my apache server after making some changes to configuration settings. How do I start/stop/restart apache server ?

CentOS / RHEL

If you are using CentOS / RHEL then type the following commands

Start Apache server

# service httpd start

Stop Apache server

# service httpd stop

Restart Apache server

# service httpd start

You can also use following commands:

# /etc/init.d/httpd start
# /etc/init.d/httpd stop
# /etc/init.d/httpd restart

Please note that restart option is a shorthand way of stopping and then starting the Apache Server. You need to restart server whenever you make changes to configuration settings. It is also good idea to check configuration error before typing restart option:

# httpd -t

Sample outputs

Syntax OK

Debian / Ubuntu

If you are using Debian / Ubuntu then type the following commands

Start Apache server

# service apache2 start

Stop Apache server

# service apache2 stop

Restart Apache server

# service apache2 start

You can also use following commands:

# /etc/init.d/apache2 start
# /etc/init.d/apache2 stop
# /etc/init.d/apache2 restart

The post Linux Start / Stop / Restart Apache Server appeared first on lifeLinux: Linux Tips, Hacks, Tutorials, Ebooks.

Memcache extension provides handy procedural and object oriented interface to memcached, highly effective caching daemon, which was especially designed to decrease database load in dynamic web applications. This article will explain how to install the memcache PHP extension on Centos/RedHat/Fedora.

The first, download the latest & stable package from http://pecl.php.net/package/memcache. Type the following command

# wget http://pecl.php.net/get/memcache-2.2.6.tgz

Extract memcache-2.2.6.tgz

# tar zxvf memcache-2.2.6.tgz

To install memcache extension, you need to install the php-devel package that matches the version of php that you are currently running. Example, i’m using PHP 5.3 then enter

# yum install php53-devel

Run the phpize command to prepare the build environment for a PHP extension

# phpize

Sample output

Configuring for:
PHP Api Version:         20090626
Zend Module Api No:      20090626
Zend Extension Api No:   220090626

Configure & Install memcache extension. Type the following command

# ./configure
# make
# make install

If your get the following error message when run ./configure

checking for the location of ZLIB... no
checking for the location of zlib... configure: error: memcache support requires ZLIB. Use --with-zlib-dir= to specify prefix where ZLIB include and library are located

Then type the following command to fix it

# yum install zlib zlib-devel

Finally, use the following command to add memcache extension to php.ini

# echo "extension=memcache.so" >> /etc/php.ini

The post How To Install Memcache PHP Extension appeared first on lifeLinux: Linux Tips, Hacks, Tutorials, Ebooks.

Iptables should be installed by default on all CentOS 3.x, 4.x and 5.x installations. You can check to see if iptables is installed on your system by:

# rpm -q iptables

Sample output

iptables-1.3.5-5.3.el5_4.1

How to enable firewall

Login as root and type the following command

# /etc/init.d/iptables start
# chkconfig iptables on

If you are using IPv6, enter:

# /etc/init.d/ip6tables start
# chkconfig ip6tables on

And to see if iptables is actually running, we can check that the iptables modules are loaded, type the following command

# lsmod | grep ip_tables

Something look like:

ip_tables              29288  1 iptable_filter
x_tables               29192  6 ip6t_REJECT,ip6_tables,ipt_REJECT,xt_state,xt_tcpudp,ip_tables

How to disable firewall

Login as root and type the following command

# /etc/init.d/iptables stop
# chkconfig iptables off

If you are using IPv6, enter:

# /etc/init.d/ip6tables stop
# chkconfig ip6tables off

The post How To Enable/Disable Firewall On Centos / RedHat / Fedora appeared first on lifeLinux: Linux Tips, Hacks, Tutorials, Ebooks.