PhpMyadmin is a fantastic tool that gives you an easy to use web interface that lets you manage a MySQL database. You can install PhpMyAdmin by downloading the source files from the official website and placing them onto your web server following the config. Better news is that there is actually a package on Centos and Red Had operating systems that will let you install it through the command line.

In order to get access to phpmyadmin via yum you will need to enable the epel repository. Execute the following commands to install epel and phpmyadmin.

Once this has completed you will now have phpmyadmin installed on your server. You will need to restart apache in order for it to pick up the new conf files that were created when apache was installed.

If you now visit “/phpmyadmin” for your website e.g. http://website.com/phpmyadmin. You will be able to gain access to the UI. Chances are you will encounter permission issues trying to access this. I constantly get this error when i first install phpmyadmin. In order to be able to use PhpMyAdmin without getting permission errors go to /etc/httpd/conf.d/phpmyadmin.conf. Replace the contents of the file with the following and restart apache after.

Save this file and restart apache

Try visit the URL again and you should now have access to phpmyadmin.

 

When running a web server it’s vital that you have you important that you have applications like apache and mysql start when the system does. Who knows what might trigger a reboot and even more, you don’t want to perform a quick restart and have the entire server crumble. Well fear not, it is very easy to set up your system for running applications on system startup.

The following command will work for Centos and Red Hat Linux.

Run the above command in your command line tool and mysql will be set to start when the system does. Replace mysql with another application name such as httpd to make that application start up on boot too.

command line

The grep command can be used to display the contents of a file and ignore the lines that are commented. This can be useful when quickly checking what options are enabled for certain applications without having to look through large amounts of commented text.

For this example we will use grep to ignore all lines that start with a # in a file stored on the system. The command will first take the config options that will tell grep to ignore lines that begin with a # and the second will be the location of the file that you want to read.

The contents of this file are

The following output is returned when the above command is ran on this file.

command line

First you will need to install cron on the system. Type the following to install cron in CentOS 6.

Set cron to start when the system starts by executing chkconfig.

Now that cron has been installed on the system you can add tasks to your cron tab. The crontab file is located in /etc/crontab (This is a file with no extension, not a folder). The file might contain something like this.

To make your life very easy there is a tool that will generate the crontab line for you. Use the form to setup frequency you want the task to run and it will provide you with the line of code that you add to your crontab file.

http://www.crontab-generator.org/

Apache Logo

There are several ways to protect a directory from URL access but most of these will also block your website from being able to access them. Heres what you do to protect a directory from being accessed by a URL but still let your website access the contents of the directory.

Open the directory you want to protect and create a new file called “.htaccess”. Open the file and add the following line of code.

Save the file and try access the directory. You should get a forbidden error e.g. “You don’t have permission to access /images/ on this server.”. If you check your website the images should still be showing up.

You will need to add a .htaccess file to every directory that you want to protect.

apache subversion

When using SVN via command line you can view the details of previous revisions by viewing the SVN log. Call the log along with the number of revisions you want to have returned to you will display the message left when the file was committed, number of lines changed, user, date and a few other details. Ideally you would have access to a GUI tool such as tortoise SVN which will give you a much more feature rich log along with the ability to compare current revisions with past revisions.

In order for this to work you need to be in the directory of an SVN checkout. If you do this in a directory that is not a SVN folder you will get an error message due to an unrecognized directory.

If you want to display everything within a specific date range you can use the following

If you want to list everything (may not be all that good of an idea if you have a huge amount of revisions).

Ascending Order

Descending Order