After you set up your WordPress Blog you will soon come to the point where you need to change the file permissions because some things might not work like you want them to. E.g. if you want to customize some things via the backend of your installation.
Many times the reason for this is quite simple. The files you want to edit don’t have the needed file permissions. It is kind of simple to change the permissions to the needed settings.
Changing the File Permissions
First start your FTP-program and switch to the folder in which your WordPress files are. Usually they are in the root-folder of your webspace. So know you will need to know where the file which you want to edit via the backend is. If you do some theme customizing it usually is in the folder „yourdomain.com/wp-conten/themes/yourtheme“.
If you never changed the rights of these files they should have the permissions 644. So for what does this number stand for? The 644 stands for a simple system which lets you switch the file permission with a ftp-program easily. Each number you can see in there is an octal number, and has its own octal value. If you want to understand the whole thing you should know some basics about numeral systems.
In a few words: There are different methods how you can „count“ numbers, there is the binary system, which only has the numbers 0 and 1, there is an decimal system, which is the „normal“ system, there is the hexadecimal system which also has letters from A to F. The most important fact is the thing that it is important at which position the number is. You can easily see the difference 19 and 91 are kind of different, so is the binary number 1100 (=12) and 0011 (=3).
If you don’t know the basics it is ok too, just try to remember for what each number is. If you want to get additional information about it, you should take a look at the informative wikipedia.org article about file permissions. The system is quite easy once you get used to it. To the additional info about this take a look at the great wikipedia.org entry.
In a nutshell: If you want to switch something in your blog which needs other file permission settings you can switch it easily with your ftp-client. After you changed it you go and switch the settings back to the old file permissions. I would definitely not recommend to you, to let it set to 777. It is a huge security risk!
So, how you can see changing the file permissions is quite easy if you once know how you can do it. After you changed something you should always switch the file permissions to its standard value.