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A Computer And Internet Glossary
When you use computers and the Internet in your business, it's
all too easy to start feeling like you're drowning in a sea of
nonsense. Computer-related things tend to have a language all
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The basics of scanning
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The Three Basic Types Of Computer Mouse
Mechanical: This is a type of computer mouse that has a rubber or metal ball on its underside and it can roll in every direction. Sensors within the mouse, which are mechanical, detect the direction in which the ball is moving and moves the...
Unleash The Dragon … Inside Your Computer!
What can you do to avoid computer slow down? – Part One Last week I promised you an article about avoiding computer slowdowns. The topic is so close to the hearts of most computer owners that I want to write about it over two articles instead of...
Your Computer May Be Infected. Here's How To Check.. (NOT about virus)
NOTE: Please take time to read on - it may be vital for your PC's security. If you are not in the mood, just save it or print it out for later reference. A recent research revealed that 80% of the computers today is infected with these dangerous...
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Setting File Permissions On A Unix Server
File permissions are one of the strengths that the Unix world has had over it's Windows contemporaries. Permissions are a means to control access to information on a computer, on a file by file basis. There are several layers of control, and these will be discussed below.
For the purpose of this series of tutorials, I have been using a free FTP program called Core FTP Lite to upload files to my server. I am using
this program to describe my examples.
Ok, to begin, let's say that we have uploaded some files to a server.
We are discussing uploading scripts in general here, and certainly for many scripts, the creators may well specify certain 'permissions' that need to be set in order for the scripts to operate correctly. Let's take a look at a set of files on a server. In Core FTP Lite, the server files are shown in the right hand pane. Select one and then right click on the highlighted file.If you use a
different FTP client, I expect that the layout will be very similar.
Run the mouse down to the bottom of the menu and select the item marked 'Properties'. Click on this option, and another dialog will appear.
You will see that the file in question (in this case a directory) is being shown in the 'File' field at the top of the screen.
What we are really interested in, is the tick boxes in the bottom half of the screen. These hold the file 'privileges' or 'permissions' for this file or directory.
There are three types of 'permissions' available.
* User - which means the person signed on who is setting the permissions
* Group - which means a specific group of users for whom access to the file has been granted
/>
* World - which means everyone.
Within these groups of users, there are 3 distinct types of permissions
* Read - which means that permission to read a file, but not alter it or run it
* Write - which means permission to write to a file and change it
* Execute - which means permission to execute a file, which is important in the case of scripts for example.
Permissions are sometimes called by these names (read, write, execute) but are more commonly
referred to using letters 'rwx'. In addition, permissions are sometimes referred to by a single
number '755' for example. In the picture above, you will see a value box. This is the number
being referred to. How is this number made up? Well let me explain.
Read
User 400
Group 40
World 4
Write
User 200
Group 20
World 2
Execute
User 100
Group 10
World 1
Each value for each setting is shown. Try them out by ticking them, and see the number in the
'Value' field change accordingly.
So, lets look at a real example
Can you see how the number 755 is made up? Add up the individual values from the value table and
see.
So hopefully you can see, that setting file permissions with the right tool is not hard at all.
Charlie Cory is an online entrepreneur, dividing his time between his business and his family. You can see a copy of this article with graphics at
Setting file permissions
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