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 worked or many years running a HelpDesk for a software house, and has experience in many operatng systems and technologies. The online aticle contains many pictures which help bring this tutorial to life.

setting file permissons

cleaning help near Mundelein ..
In The News:

A phone phishing attack compromised Harvard's alumni and donor database, marking the second security incident at the university in recent months.
AutoFlight's zero-carbon floating vertiport uses solar power to charge eVTOL aircraft while supporting emergency response, tourism, and marine energy maintenance.
A new phone return scam targets recent buyers with fake carrier calls. Learn how criminals steal devices and steps to protect yourself from this fraud.
New Anthropic research reveals how AI reward hacking leads to dangerous behaviors, including models giving harmful advice like drinking bleach to users seeking help.
The Fox News AI Newsletter gives readers the latest AI technology advancements, covering the challenges and opportunities AI presents.
Holiday email scams, including non-delivery fraud and gift card schemes, spike in November and December, costing victims hundreds of millions, the FBI says.
Holiday visits offer the perfect opportunity to help older parents with technology updates, scam protection and basic troubleshooting skills for safer digital experiences.
Swiss scientists create grain-sized robot that surgeons control with magnets to deliver medicine precisely through blood vessels in medical breakthrough.
Researchers exploited WhatsApp's API vulnerability to scrape 3.5 billion phone numbers. Learn how this massive data breach happened and protect yourself.
Travel companies share passenger data with third parties during holidays, but travelers can protect themselves by removing data from broker sites and using aliases.
Xpeng's humanoid robot moves so realistically that crowds believed it was fake, marking a major advancement in robotics technology ahead of 2026 commercial launch.
Researchers discover phishing scam using invisible characters to evade email security, with protection tips including password managers and two-factor authentication.
iPhone and Android users can reduce battery drain and data usage by restricting Background App Refresh to Wi-Fi connections instead of mobile networks.
Scammers nearly stole an Apple account by exploiting the support system with authentic-looking tickets and phone calls, users can protect themselves with safety steps.
FoloToy restored sales of its AI teddy bear Kumma after a weeklong suspension following safety group findings of risky and inappropriate responses to children.
Threat intelligence firm Synthient uncovers one of the largest password exposures ever, prompting immediate security recommendations.
Viral video shared by Elon Musk shows Tesla's Optimus humanoid robots performing tasks from cooking to construction, garnering over 58.5 million views on social media.
Chinese hackers used Anthropic's Claude AI to launch autonomous cyberattacks on 30 organizations worldwide, marking a major shift in cybersecurity threats.
Apple's new Sleep Score feature gives you a rating for your nightly rest quality. Learn how to set it up on your Apple Watch and iPhone today.
Essential phone settings to enable before losing your device, including Find My network, location services and security features for iPhone and Android.
The Fox News AI Newsletter gives readers the latest AI technology advancements, covering the challenges and opportunities AI presents.
Cybersecurity research shows weak passwords remain a major threat, with simple patterns and number sequences putting millions of accounts at risk.
New Android malware BankBot YNRK silences phones, steals banking data and drains crypto wallets automatically. Learn how this advanced threat works.
FDA approves first human trial for Paradromics' brain-computer interface that could restore speech for paralyzed patients through neural technology.
New phishing platform QRR targets Microsoft 365 users across 1,000 domains in 90 countries. Learn how to spot fake login pages and protect your accounts.

iPod users get the picture

iPod users start to get the picture and it's turning... Read More

Consumer Electronic Information: The Basics of the DLP Projector

Projectors have come a long way in the past few... Read More

Lightning Season: How to Avoid Data Loss

We have just entered the time of year that most... Read More

Basic Computer Maintenance

One of the most common questions computer users ask is,... Read More

EDTV vs HDTV

Confused by EDTV vs HDTV? We don't blame you. The... Read More

PDA Bible Free Download

Your Bible At Your FingertipsIt is fairly easy to find... Read More

Digital Cameras: How Many Pixels Do I Need?

With the bewildering number of digital cameras on the market,... Read More

A Lesson in HTML

As the owner of a Country Mall and Top Site... Read More

Bluetooth Technology: Tips for Buying Headsets or Headphones

The technological horizon has always got something new to offer,... Read More

Three Things You Can Do to Keep Your Computer Running at Maximum Performance

Although there are many things that can affect the performance... Read More

Gain Control Over Your Screensavers With These Simple Steps

We all enjoy our favorite screensavers but in the same... Read More

10 Time Saving Keyboard Shortcuts

Time is money. And when you constantly have to divide... Read More

Home Video? Bring it On

So you got yourself a digital camcorder. If you want... Read More

Image Formats: GIF, JPEG, BMP

When browsing the internet you are likely to come across... Read More

Is DVD Storage An Attractive Alternative For Your Computer Backup?

If you have a computer for home use or for... Read More

Enhanced Web Browsing With Toolbars

As the Web grows more crowded and just plain "noisy"... Read More

Basic Problem in a PC

I have a p3 500MHz PC with 128MB RAM, 10.2... Read More

Digital Cameras Ratings Abolish Camera Comparison Guesswork

Digital cameras ratings are great tools for deciding which camera... Read More

HTML Explained: Part 1

Want to save money while promoting your web-based business? Of... Read More

FTP - File Transfer Protocol Explained

File Transfer Protocol (FTP) is a protocol that is part... Read More

Learn the Lost Art of Touch Typing

Computers have replaced typewriters, but two-finger, hunt-and-peck typing can never... Read More

What are the Main Components of Any Computer, and Which are the Most Critical to Its Performance?

Computers are everywhere, and vary in specification, brands, sizes, shaped,... Read More

Some Thoughts on Choosing a Flash MP3 Player

Flash mp3 players come with an exciting array of features,... Read More

The Many Benefits of Owning a DVR

Has This Ever Happened To You? OK.. it's Friday night,... Read More

Virtual Memory - What is It?

I recently got an e-mail asking about virtual memory. The... Read More

reliable maid service Wilmette ..