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

In The News:
table border=0 width= valign=top cellpadding=2 cellspacing=7trtd valign=top class=jfont style=font-size:85%;font-family:arial,sans-serifbrdiv style=padding-top:0.8em;img alt= height=1 width=1/divdiv class=lha href=http://www.citywebshopper.net/articles/includes/redirect.php?url=http://webworkerdaily.com/2008/10/09/open-thread-hows-your-personal-tech-spending/cid=0ei=6yzwSMWxAo3W6gOC2smwAwusg=AFQjCNFBJXbsh8LPsVLq6O0S7hWLoxL7lwOpen Thread: How’s Your bPersonal Tech/b Spending?/abrfont size=-1font color=#6f6f6fWebWorkerDaily,nbsp;CAnbsp;-/font nobrOct 9, 2008/nobr/fontbrfont size=-1As the larger economic picture continues to look dismal, the reverberations are being felt within the btech/b sector. As our parent blog GigaOM reports, b.../b/font/div/font/td/tr/table
table border=0 width= valign=top cellpadding=2 cellspacing=7trtd valign=top class=jfont style=font-size:85%;font-family:arial,sans-serifbrdiv style=padding-top:0.8em;img alt= height=1 width=1/divdiv class=lha href=http://www.citywebshopper.net/articles/includes/redirect.php?url=http://www.sltrib.com/tv/ci_10653836cid=0ei=6yzwSMWxAo3W6gOC2smwAwusg=AFQjCNH5-kT-B6fxwB8vjSk4LYzwuGk7RQbPersonal Tech/b: Ready or not, digital TV is coming to Utah/abrfont size=-1font color=#6f6f6fSalt Lake Tribune,nbsp;United Statesnbsp;-/font nobrOct 7, 2008/nobr/fontbrfont size=-1By Vince Horiuchi Come Feb. 17, all broadcasters will switch off their analog television signals. If you are not prepared by then, the only thing you will b.../b/font/div/font/td/tr/table
table border=0 width= valign=top cellpadding=2 cellspacing=7trtd valign=top class=jfont style=font-size:85%;font-family:arial,sans-serifbrdiv style=padding-top:0.8em;img alt= height=1 width=1/divdiv class=lha href=http://www.citywebshopper.net/articles/includes/redirect.php?url=http://www.ibtimes.com/prnews/20081010/keiretsu-forum-intel-capital-and-the-clean-tech-open-present-funding-alternatives-for-clean-tech-sta.htmcid=1256075330ei=6yzwSMWxAo3W6gOC2smwAwusg=AFQjCNF6pqmSGxNgsQv5vY0kDqUD8-m5ZgKeiretsu Forum, Intel Capital, and the Clean bTech/b Open Present b.../b/abrfont size=-1font color=#6f6f6fInternational Business Times,nbsp;NYnbsp;-/font nobr11 hours ago/nobr/fontbrfont size=-1b.../b including a KeiretsuForum member funded company and a Clean bTech/b Open alumni company, willpresent their bpersonal/b experience with raising funds. b.../b/font/div/font/td/tr/table
table border=0 width= valign=top cellpadding=2 cellspacing=7trtd valign=top class=jfont style=font-size:85%;font-family:arial,sans-serifbrdiv style=padding-top:0.8em;img alt= height=1 width=1/divdiv class=lha href=http://www.citywebshopper.net/articles/includes/redirect.php?url=http://www.washingtonpost.com/wp-dyn/content/discussion/2008/09/30/DI2008093001430.htmlcid=0ei=6yzwSMWxAo3W6gOC2smwAwusg=AFQjCNG-fiOzVN2Mz8lSF7RrT4ucQQ5z5wWashington Post bPersonal Technology/b Columnist/abrfont size=-1font color=#6f6f6fWashington Post,nbsp;United Statesnbsp;-/font nobrOct 2, 2008/nobr/fontbrfont size=-1The Washington Post#39;s Rob Pegoraro will be online Thursday, Oct. 2 at 2 pm ET to discuss recent reviews and answer your bpersonal tech/b questions. b.../b/font/div/font/td/tr/table
table border=0 width= valign=top cellpadding=2 cellspacing=7trtd valign=top class=jfont style=font-size:85%;font-family:arial,sans-serifbrdiv style=padding-top:0.8em;img alt= height=1 width=1/divdiv class=lha href=http://www.citywebshopper.net/articles/includes/redirect.php?url=http://online.wsj.com/article/SB122366999999723871.html%3Fmod%3Dgooglenews_wsjcid=0ei=6yzwSMWxAo3W6gOC2smwAwusg=AFQjCNHkIBO9YxrMVRji6lZqeRWSKhCAUAFraud Ring Uses High-bTech/b Devices to Steal Card Data in Europe/abrfont size=-1font color=#6f6f6fWall Street Journalnbsp;-/font nobr8 hours ago/nobr/fontbrfont size=-1It was small card containing wireless communication btechnology/b. The bug would read an individual#39;s card number and the corresponding bpersonal/b identification b.../b/font/div/font/td/tr/table
table border=0 width= valign=top cellpadding=2 cellspacing=7trtd valign=top class=jfont style=font-size:85%;font-family:arial,sans-serifbrdiv style=padding-top:0.8em;img alt= height=1 width=1/divdiv class=lha href=http://www.citywebshopper.net/articles/includes/redirect.php?url=http://news.cnet.com/8301-17939_109-10063426-2.htmlcid=0ei=6yzwSMWxAo3W6gOC2smwAwusg=AFQjCNHYPbVfBDdtUqx961-cm7MV4CKgZwUncov returns to heap scorn on btech/b companies/abrfont size=-1font color=#6f6f6fCNET News,nbsp;CAnbsp;-/font nobr9 hours ago/nobr/fontbrfont size=-1b.../b people in the btech/b economy read it obsessively. F***edCompany (our style guide prohibits me from actually spelling it) got so nasty, bpersonal/b, b.../b/font/div/font/td/tr/table
table border=0 width= valign=top cellpadding=2 cellspacing=7trtd width=80 align=center valign=topfont style=font-size:85%;font-family:arial,sans-serifa href=http://www.citywebshopper.net/articles/includes/redirect.php?url=http://www.boston.com/business/technology/articles/2008/09/29/tokyoflash_goes_negativecid=0ei=6yzwSMWxAo3W6gOC2smwAwusg=AFQjCNE9xQgz3wqNd8JSxrXsox2mLisPBQimg src=http://news.google.com/news?imgefp=9-_xLmBU-W8Jimgurl=cache.boston.com/resize/bonzai-fba/Globe_Photo/2008/09/28/1222653963_8369/539w.jpg width=80 height=50 alt= border=1brfont size=-2Boston Globe/font/a/font/tdtd valign=top class=jfont style=font-size:85%;font-family:arial,sans-serifbrdiv style=padding-top:0.8em;img alt= height=1 width=1/divdiv class=lha href=http://www.citywebshopper.net/articles/includes/redirect.php?url=http://www.boston.com/business/technology/articles/2008/09/29/tokyoflash_goes_negativecid=0ei=6yzwSMWxAo3W6gOC2smwAwusg=AFQjCNE9xQgz3wqNd8JSxrXsox2mLisPBQbPersonal Tech/b Tokyoflash goes #39;Negative#39;/abrfont size=-1font color=#6f6f6fBoston Globe,nbsp;United Statesnbsp;-/font nobrSep 28, 2008/nobr/fontbrfont size=-1Outdoor Challenge, about $60, comes with a mat controller that looks as if it#39;s made for a high-btech/b version of Twister. The mat controller is an excellent b.../b/font/div/font/td/tr/table
table border=0 width= valign=top cellpadding=2 cellspacing=7trtd width=80 align=center valign=topfont style=font-size:85%;font-family:arial,sans-serifa href=http://www.citywebshopper.net/articles/includes/redirect.php?url=http://www.dailytech.com/Micron%2BSheds%2B15%2Bof%2BWorkforce/article13171c.htmcid=1255863259ei=6yzwSMWxAo3W6gOC2smwAwusg=AFQjCNE8jJZ8o3es_irMIXL4AlXbY6uo2Aimg src=http://news.google.com/news?imgefp=BDD3QK3Z_gcJimgurl=images.dailytech.com/frontpage/fp__fp-cheech.jpg width=80 height=80 alt= border=1brfont size=-2DailyTech/font/a/font/tdtd valign=top class=jfont style=font-size:85%;font-family:arial,sans-serifbrdiv style=padding-top:0.8em;img alt= height=1 width=1/divdiv class=lha href=http://www.citywebshopper.net/articles/includes/redirect.php?url=http://www.idahostatesman.com/1251/story/528808.htmlcid=1255863259ei=6yzwSMWxAo3W6gOC2smwAwusg=AFQjCNEiCkeRR7_dcMMKHpbyYAjvQgimbAMicron cuts will echo through Treasure Valley/abrfont size=-1font color=#6f6f6fIdahoStatesman.com,nbsp;IDnbsp;-/font nobr16 hours ago/nobr/fontbrfont size=-1Micron, a computer memory-chip maker, anchor of Boise#39;s btech/b sector and Idaho#39;s largest private employer, said Thursday it will stop making flash memory in b.../b/fontbrfont size=-1a href=http://www.citywebshopper.net/articles/includes/redirect.php?url=http://infotech.indiatimes.com/News/Micron_Tech_to_cut_2850_jobs/articleshow/3579659.cmscid=1255863259ei=6yzwSMWxAo3W6gOC2smwAwusg=AFQjCNEdekkAs5iZ4mn7DOg6ysAUdtwVgAMicron bTech/b to cut 2850 jobs/a font size=-1 color=#6f6f6fnobrIndiatimes/nobr/font/fontbrfont class=p size=-1a class=p href=http://news.google.com/news?sourceid=navclientie=ISO-8859-1rls=GGLG,GGLG:2005-22,GGLG:enncl=1255863259hl=ennobrall 286 news articles/nobr/a/font/div/font/td/tr/table
table border=0 width= valign=top cellpadding=2 cellspacing=7trtd width=80 align=center valign=topfont style=font-size:85%;font-family:arial,sans-serifa href=http://www.citywebshopper.net/articles/includes/redirect.php?url=http://www.theonlinewire.com/articleView.aspx%3FID%3D4153cid=1254997548ei=6yzwSMWxAo3W6gOC2smwAwusg=AFQjCNFnefZ_u8k6EgElM-rZhuMRNX_OGQimg src=http://news.google.com/news?imgefp=6GStHnvThZMJimgurl=www.theonlinewire.com/images/oklahoma10102.jpg width=80 height=80 alt= border=1brfont size=-2TheOnlinewire/font/a/font/tdtd valign=top class=jfont style=font-size:85%;font-family:arial,sans-serifbrdiv style=padding-top:0.8em;img alt= height=1 width=1/divdiv class=lha href=http://www.citywebshopper.net/articles/includes/redirect.php?url=http://sports-odds.com/american-football/101008-nebraska-vs-texas-tech-college-football-picks.htmlcid=1254997548ei=6yzwSMWxAo3W6gOC2smwAwusg=AFQjCNHP3VIO3_kSyhne63F-aF7mxg1I9QNebraska vs Texas bTech/b College Football Picks/abrfont size=-1font color=#6f6f6fSports-Odds.com,nbsp;FLnbsp;-/font nobr16 hours ago/nobr/fontbrfont size=-1quot;Not only the bpersonal/b fouls, but putting ourselves in first-and-15 and some of the things that happen there. We need to be more disciplined and take care b.../b/fontbrfont size=-1a href=http://www.citywebshopper.net/articles/includes/redirect.php?url=http://www.chron.com/disp/story.mpl/headline/sports/6048050.htmlcid=1254997548ei=6yzwSMWxAo3W6gOC2smwAwusg=AFQjCNGwl1JRE01kXnmqnN8ckNtkYfORyABig 12 Notebook: Mizzou, Oklahoma St. tough to stop/a font size=-1 color=#6f6f6fnobrHouston Chronicle/nobr/font/fontbrfont size=-1a href=http://www.citywebshopper.net/articles/includes/redirect.php?url=http://www.rockymountainnews.com/news/2008/oct/09/brooks-things-are-looking-up-for-texas-against/cid=1254997548ei=6yzwSMWxAo3W6gOC2smwAwusg=AFQjCNEFqluHjDAU1mqdC2vR6CPzzZakpQBROOKS: Things are looking up for Texas against Oklahoma/a font size=-1 color=#6f6f6fnobrRocky Mountain News/nobr/font/fontbrfont size=-1a href=http://www.citywebshopper.net/articles/includes/redirect.php?url=http://www.timescall.com/sports_story.asp%3Fid%3D12024cid=1254997548ei=6yzwSMWxAo3W6gOC2smwAwusg=AFQjCNFMPGs4APBsINn8MUSTMGF2I1B95QMissouri vs. OSU an explosive matchup/a font size=-1 color=#6f6f6fnobrLongmont Daily Times-Call/nobr/font/fontbrfont size=-1 class=pa href=http://www.citywebshopper.net/articles/includes/redirect.php?url=http://bleacherreport.com/articles/66632-chubby-chase-daniel-mizzou-havent-done-spitcid=1254997548ei=6yzwSMWxAo3W6gOC2smwAwusg=AFQjCNHBHVtAm-BbprzoKEIThSuJ_-tqCgnobrBleacher Report/nobr/anbsp;- a href=http://www.citywebshopper.net/articles/includes/redirect.php?url=http://www.dailycamera.com/news/2008/oct/07/dont-count-out-texas-tech-osu-camera-sports/cid=1254997548ei=6yzwSMWxAo3W6gOC2smwAwusg=AFQjCNHyVK2wJSf9bhBRnJ6pfTf5Qg_kvAnobrDaily Camera/nobr/a/fontbr/font class=p size=-1a class=p href=http://news.google.com/news?sourceid=navclientie=ISO-8859-1rls=GGLG,GGLG:2005-22,GGLG:enncl=1254997548hl=ennobrall 429 news articles/nobr/a/font/div/font/td/tr/table
table border=0 width= valign=top cellpadding=2 cellspacing=7trtd valign=top class=jfont style=font-size:85%;font-family:arial,sans-serifbrdiv style=padding-top:0.8em;img alt= height=1 width=1/divdiv class=lha href=http://www.citywebshopper.net/articles/includes/redirect.php?url=http://www.sltrib.com/travel/ci_10532234cid=1249758104ei=6yzwSMWxAo3W6gOC2smwAwusg=AFQjCNE27XNbmae6XCmh-Ga9tatz33aFPwbPersonal Tech/b: Security agency testing X-ray portal for vehicles/abrfont size=-1font color=#6f6f6fSalt Lake Tribune,nbsp;United Statesnbsp;-/font nobrSep 23, 2008/nobr/fontbrfont size=-1A new X-ray btechnology/b is being tested that will allow inspection of vehicles as they are coming into an airport. The new security measure has raised b.../b/font/div/font/td/tr/table
personal tech - Google News


Wind Chimes and more...

Windchimes for great gifts!

Build Your Own Computer

I'm eighty-one years old and I bought my first computer... Read More

10 Time Saving Keyboard Shortcuts

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

MobiTV and Visual Stimulation Imput for Personal Cognitive Performance

Stimulus thru Caffiene or Visual Input?It appears that the Mobi... Read More

Gain Control Over Your Screensavers With These Simple Steps

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

Troubleshooting Computer Freeze (Lockup) Problems

How familiar does the following sound? Your computer was working... Read More

Image Conversion In Computers

JPEG, GIFF/JIFF, BMP, and TIFF are the most commonly used... Read More

Make Windows XP Run Faster!

A friend told me: "My computer startup seems to be... Read More

How To Speed Up Your Aging PC And Make It Healthier Too

With a little tweaking and with proper tools, you can... Read More

Bluetooth Technology: Tips for Buying Headsets or Headphones

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

Help, I Need a New HDTV! (Part 4 of 5)

Feeling overwhelmed in selecting a new TV? With all the... Read More

How To Safeguard Your Computer?

The following practice, if done regularly, may help you to... Read More

Protect Your PC from Viruses, Worms & Trojans

Each of the items in the checklist below is part... Read More

The Benefits of the New Firefox Browser

You probably heard of the new Firefox browser version 1.0... Read More

Improve PC Performance - 6 Tips You Must Know

Are you frustrated with your PC?Is it feeling sluggish or... Read More

Compile .BAT Files into Native Windows Applications (.EXE)

Since the DOS days, batch files have been one of... Read More

Registry Tools Demystified

Not sure what Windows registry is or how it works?... Read More

Keeping the Windows Registry Operational

The registry is where the computer stores information about the... Read More

Nephrology and Dialysis For a PDA

Saving Lives With A Pocket PCFree medical downloads can be... Read More

Why There Are Color Differences in Printing from Your PC

This article describes the basic properties of color, what the... Read More

How To Remove One Operating System from a Dual Boot Windows XP Computer

In Windows Xp, you can install two operating systems on... Read More

Cisco Certification: Building Your Home Lab, Part II

In the first part of this home lab tutorial, CCNA... Read More

Tips for Buying a PC

Buying Your PCBuying a PC that's right for you and... Read More

Buying a Home Theater Receiver

Buying a receiver is one of the most important decisions... Read More

Cut Through the Hype and Make the Right Digital Camera Comparisons

There are soooo many choices. With all the styles and... Read More

Is Desktop Search Deserving?

Google, in their march to stay ahead of the pack... Read More