Friday, October 18, 2002

FXP (File Exchange Protocol) - Flash! Ahhh-ahhhhhhh... He'll save every one of us!

Friday, October 18, 2002 0

No, I'm not repeating myself; there is a subtle difference between the FTP and FXP protocols. The former allows you to transfer data from a remote computer to your hard drive, while the latter enables you to transfer data from one FTP site to another FTP site.

By setting up an FXP transfer you are tapping the slower of the two connection speeds of the computers you wish to transfer data between. So even if you only have a 56k modem, it is possible to transfer data at the speed of a T3 connection for example. The speed of your own connection has no bearing on the transfer rate because you are merely acting as the catalyst; the data never actually touches your own hard drive. One instance in which you might find this technique useful is when switching web hosts - if your site contains a sizeable library of video or music content, transferring it from A to B will take a fraction of the time it would armed only with your meagre home connection.

To get started you will need an FXP client. There aren't that many around to choose from, but luckily what is available is top notch - head over to and see for yourself. Before you can continue you will need a destination FTP site to transfer your data to. This could be any computer providing it has been setup as an FTP server and you know the login details.

Whenever you open a Flash FXP session you will be presented with a split screen display. The left side of the screen is used for browsing the remote FTP site you wish to transfer data from, and the right side of the screen is used for browsing the destination FTP site. To begin with you will have to enter the IP address of the FTP site you wish to transfer data from. To do this, click on the yellow lightning bolt icon, select 'quick connect', fill in the login details and click on the 'connect' button. Switch to the opposite side of the screen, select 'quick connect' once again and enter the login details of your destination FTP site. All that remains to be done is to decide what it is you wish to transfer and give Flash FXP the go ahead. The procedure is as follows:- highlight a selection of files, jab the 'add to queue' option and push the 'go' button. Finally, sit back and put your feet up while you watch the megabytes accumulate.

Ah, this would be the paragraph where I moan about some of the drawbacks that blight FXP - just for the sake of completeness you understand. One of the most pertinent issues is that not all FTP sites will grant you permission to transfer data to another FTP. The reason for this is that to use FXP, both hosts must support PASV mode and allow PORT commands to foreign hosts, and clearly not all do. Something to consider when using free web space or a paid, shared, virtual account is the type of files you are allowed to store in your account. Some web host administrators, for example, will forbid you from transferring mp3 or zip files just in case they contain copyright infringing material.

These considerations aside, FXP is a skill worth mastering by any webmaster or server admin who deals with large files on a regular basis. You are unlikely to ever have access at home to the kind of bandwidth available through corporate networks so this is the next best thing.

Saturday, October 12, 2002

Web forums under the microscope

Saturday, October 12, 2002 0

These are an invaluable resource - say you've been struggling with a technical dilemma and there's no-one with sufficient computer know-how around to ask for help. Your next move shouldn't be to ring up a premium rate technical support line. Why bother when you can always guarantee there will be someone out there in cyberspace who knows exactly what the problem is and how to fix it, and who will be more than happy to impart this knowledge for free?

Let's skip the preamble for a change and jump straight in at the deep end shall we? - don't worry, I'll supply the arm bands! Having found a bulletin board/forum (the two terms are used interchangeably) you like the look of, click on the 'register' link. Now choose an alias, make a polite request for assistance and wait for a reply; you will discover that more often than not, people will do their best to help you out without asking for anything in return. Even if you aren't seeking specific technical support, forums are great places to help you keep up to date with news and rumours relating to a myriad of disparate topics, discover new web sites or simply meet and talk to like-minded people.

You will find that many bulletin boards are attached to particular web sites and so share the same name, while others are 'stand-alone' - the forum is the web site. These forums will fall into one of two categories; they will either be hosted on a private or rented server and will be maintained by the owner, or they will be remotely hosted and managed by a third party company. A further factor which differentiates forums is the scripting language used to produce them, the most familiar flavours being PHP, Perl and ASP (refer to my forum construction tutorial for further details). The busiest and longest established boards tend to use the Ultimate Bulletin Board or vBulletin script. The main advantage with using UBB or vBulletin is that they can be run from your own server allowing you to have complete control over their implementation, yet another attraction is that they are literally brimming with gadgets and gizmos which can't be found in the majority of remotely hosted boards. Any features not included by default can be 'hacked' into the board manually using nothing more sophisticated than Notepad or an equivalent text editor. These 'hacks' can be added or removed at any time to enhance the board's functionality, tighten up security or just improve its aesthetic appeal.

UBB and vB are expensive, commercial grade scripts and so are not best suited to small hobby sites running on a shoestring budget. This isn't to say you can't get hold of a top quality, professional forum script without investing lots of cash - there are plenty of completely free alternatives available which are considered worthy rivals to the two market leaders (again, see my DIY forum guide for examples). So, at least in theory, anyone can set up their own forum. The main reason many people choose not to do so is because it is so difficult to find the right kind of free, reliable hosting with ample server space. Then again, another stumbling block which tends to put people off setting up a do-it-yourself bulletin board is that initially the installation procedure can appear quite a daunting prospect - although, in actual fact if you can read a text file and follow a set of instructions you're well on your way to setting up your very own board.

This drawback leads me quite nicely onto explaining the second category of bulletin boards; those which are remotely hosted and managed by a third party organization, the most common one being EzBoard Inc. The name derives from the fact that they are very straight forward to set up and configure - who'd have thunk it? Anyone can run their own EzBoard by simply going along to and filling in a few brief forms. The difference between a remotely hosted board such as EzBoard and a DIY board is that the former are maintained by someone else, the clear advantage being that you can avoid all the frustration and expense of searching for a web host.

Another significant plus of opting for a remotely hosted solution is that they mostly require zero investment - you aren't required to purchase the pre-installed script, or pay for hosting since these expenses are recouped through selling advertising space. EzBoards are entirely customizable and therefore can be configured to suit your personal preferences. Also, as they are constantly being updated and improved, many people now believe they are just as functional as the more complicated, DIY forum scripts. Although by using an EzBoard, or any other remotely hosted board for that matter, you avoid all the maintenance hassles which go hand in hand with DIY scripts, you do have the added worry that the company hosting it could pull the plug at any time should they discover that their services are not financially viable - it happens all the time in the .com industry.

No matter which type of board you are using, a very useful, often overlooked, feature is the humble search button. Many people just jump straight in with both feet to make a plea for help without searching through the previous posts first. More than likely someone else will have already asked the same question or posted the same must-visit link, so before adding your two penny's worth, take the time to make sure one way or the other.

If you are looking for a technical solution that specifically relates to the latest version of an application or piece of hardware, it is often more productive to limit your search to messages that were posted within the last month or so. This will improve your chances of finding relevant information. On the other hand, if your query isn't quite so time-sensitive, you should search the whole back catalogue of posts for best results.

The search function is also useful if you yourself have made many posts and have lost track of which forums you have posted in and which people you have replied to. In this case, instead of searching for keywords you would conduct a search using your own username. This is effective as long as you remember to type your alias into the 'search by username' box rather than the 'search words' box; a very common mistake which will return very few hits. While we're on the subject of keeping up to date with other people's replies to your posts, another good tip is to enable the email notification feature whenever you make a new post. That way whenever someone replies to one of your messages you will receive an email to say, "what's-his-name has replied to the following topic and you can read their comments by clicking on this link". To enable this feature for individual posts make sure you tick the 'email notification' box whenever you initiate a new discussion or contribute to an ongoing discussion. It is also possible to switch on this feature on a global basis so as to make email notification the default option.

If you have already visited a few bulletin boards you may have come across a range of icons, which look like little faces making exaggerated expressions. These are known as 'smilies' - simple keyboard characters used to convey emotions such as a smile or a frown. Providing you are using a board that supports these smilie faces, all you have to do to produce them is type a two, three or four character code (without spaces) into your post. These are then automatically converted into the relevant graphical representation. Five basic smilies are supported by almost all modern bulletin boards. These are as follows...

:) = a smile
:( = a frown/unhappy
:o = embarrassment

:D = a big grin
;) = a wink

Note that they make much more sense if you tilt your head to the left like an Andrex puppy. The dopey, befuddled expression is optional.

For a more comprehensive array of smilies you can insert into forum posts pay Crack's Smilies a visit. You won't find a larger collection anywhere.

There are many more smilies you might want to familiarize yourself with. Even if these aren't automatically converted into a graphical icon most people will know what you mean. The use of smilies isn't just restricted to bulletin boards. They can appear anywhere where it is possible to post information for others to see; web sites, chat rooms, mailing lists, email and so on. If these are used in email, none of the codes will be converted to icons so you should quickly be able learn what each symbol represents and use them without thinking about it. A few of the less obvious examples include:

:-/ = perplexed
:-* = oops
:-x = a kiss
%-/ = hung over
8-) = excited
;-( = grumpy

:-@ = a scream
:-0 = shock
;-} = a leer
$-) = yuppie
7:-) = baseball cap
:-& - tongue-tied

Bulletin boards (and the net in general) are home to a hotbed of abbreviations so it also helps if you can recognize what these shorthand expressions mean whenever they crop up. Here are some of the most commonly used examples:

BTW = By the way
ROTFL = Rolling on the floor laughing
LOL = Laugh out loud
FWIW = For what it's worth
CYA = See ya around
IMHO = In my humble opinion
SGAL = Sheesh, get a life
CUL8R = See you later
IANAL = I'm not a lawyer, but...
SOHF = Sense of humour failure
TTTT = To tell the truth
HTH = Hope this helps
PTMM = Please tell me more
YIU = Yes, I understand
BFN = Bye for now
WTF = What the f*#k?
LMAO = Laughing my ass off
ROFLMAO = Rolling on the floor laughing my ass off
JK = Just kidding
DL = Download
UL = Upload
RTFM = Read the f*#king manual
TIA - Thanks in advance
IC = I see
FYI = For your information
THX = ThanksL8R = See you later
TTFN = Ta ta for now
TTYL = Talk to you later
PLZ = Please
REQ = Request
UIN = Universal identification number (or ICQ number)
NFO = Information
L/P = Login/password
M8 = Mate
AAMOF = As a matter of fact
AFAIK = As far as I know
AFAIC = As far as I'm concerned
AFAICT = As far as I can tell
ASAP = As soon as possible
CWOT = Complete waste of time
TOS = Terms of service
WYSIWYG = What you see is what you get
OMG = Oh my god

As a board grows in popularity it becomes necessary to give a certain few, carefully selected people 'moderator' status. A moderator is like a policeman/woman who patrols the board making sure everything runs as smoothly as possible. They are usually assigned control over an area of the forum specifically designated for the discussion of a particular topic of which they have the most knowledge, but quite often you will see the same mods watching over multiple forums - these are known as super mods, and to prove it they sport 's' shaped quiffs - actually I made that last bit up. Both varieties have the power to edit, delete, censor or prune any posts in the forums they manage. Related duties include keeping posts spam-free and friendly, and answering any questions the board members may have.

If you're not sure who the moderators of a particular forum are, look out for users who have accumulated hundreds or even thousands of posts and have lots of flashing stars or other distinctive paraphernalia under their name. In any case, the words 'moderator' will usually appear under their username - bit of a giveaway that! If you're interested in becoming a moderator yourself, the best route to take is to get yourself well established on a board by making a lot of helpful posts. On a computer oriented forum it's especially useful if you have a lot of technical knowledge. Try not to become preoccupied with fast-tracking your way up the status hierarchy. Instead relax, learn to enjoy yourself and help out as much as possible without expecting to be rewarded. If you're right for the role, your talents will be recognized sooner or later. Whatever you do, don't join a forum solely for the kick of becoming a moderator - they have far more to offer than earning the right to wear a badge.

A few other forum related issues worth a mention include the use of cookies, HTML and javascript and the disappearance of posts. Firstly, cookies, the non-edible kind that is, are tiny files (usually occupying less than 1kb of hard drive space) created by scripts embedded in the web sites you visit. Cookies are stored in their own little niche within your Windows folder and are used to remember information such as the last time you logged into a web site, your username and password, and any personal preferences you may have set through your 'profile' page.

In the past, cookies have been maligned for supposedly facilitating unwarranted access to people's private accounts - dismiss what you've heard; this is a myth. Cookies can only be deciphered by the web site from which they originated, and not by just opening them in a text editor such as Notepad. They can be a problem if you use a shared computer and do not have a personal login to keep your preferences separate from those of other users, but this is hardly a cookie design fault; it's a matter for individual end users to resolve.

Another fallacy is that cookies can transit viruses. Again, this is nonsense so don't let it concern you. Cookies are simply there to enhance the speed and efficiency of your web browsing, not to cause damage to your system or steal your username and password.

Second on the mention-worthy list; the removal of posts. You may return to a forum to check if anyone has replied to a post you made the previous day and to your annoyance discover that it has mysteriously disappeared. Unless you have violated some forum regulation, have been endlessly flaming someone for no apparent reason or have posted something that is completely outrageous, your post is unlikely to have been deleted. More often than not, it will have been moved to a more relevant forum where the discussion has been allowed to continue. This brings me to one of the most basic rules governing the use of bulletin boards - post in the correct forum. This is just as much for your sake as to keep the board tidy and easy to navigate. For instance, if you post a question about web design in the games discussion forum you are unlikely to get the best possible response because anyone who has specialist knowledge of web design is more likely to spend their time visiting the web design forum, and as a result could miss your post entirely. This is one of the quickest ways to annoy the moderators so make sure you think before posting.

Third and final consideration; HTML code and javascript. On some boards you will be able to insert HTML code or javascript into your posts. If you're familiar with web design, this will enable you to add pictures, special effects and sounds to your posts or alter your text aesthetically. Many forum administrators disable this feature, quite frankly because it's annoying, it slows down the board and uses excessive bandwidth, but also because it poses a security risk when exploited by bored miscreants. If you're not sure whether or not you're allowed to post HTML code etc, keep an eye open for a phrase stating something along the lines of, "HTML code is off/on" appearing adjacent to the message dialogue box whenever you make a post.

If you have visited a web design forum where HTML code/javascript is enabled you will be aware of the problems this can cause for people wishing to exchange scripts or code snippets. Under these circumstances anyone viewing posts containing HTML code or javascript would see the effects of this code rather than the raw code itself. To workaround this problem some forums allow you to place web script snippets inside [code] tags to instruct the forum software to display the code between the tags instead of attempting to interpret and transform it. Before the [code] tag was introduced it was commonplace to see posts containing images of HTML code - yes, people would actually open up their favourite paint program, type out the HTML code they wanted to post, save it as a .gif or .jpg image and then submit the picture rather than the actual code. Absolute insanity!

If you are hoping to become a well regarded member of a bulletin board community, it is imperative that you read any guidelines layed down by the administrator. Aside from a handful of unwritten rules of conduct, such as being friendly and polite, and not SHOUTING etc, these guidelines can be as diverse as the internet in general so don't assume that because you've been round the block a few times, you know it all.

Seeking out these forums can be quite a chore, which is why I've rounded up what I consider to be some of the best ones and listed them on my forum links page. However, if none of these appeal to you, you can visit the EzBoard home page or pop along to Google and carry out your own search. A final point to note is that forums cover a much wider range of topics than computers alone, so wherever your interests lie there is almost certain to be a forum out there to cater for your needs.

Friday, October 04, 2002

Why do I get CRC errors when I unzip compressed archives? What is a CRC error?

Friday, October 04, 2002 0

These occur relatively infrequently, but most people have experienced such problems at one time or another. CRC is an acronym for cyclic redundancy check, a mathematical method used to calculate the validity of the data in a given archive.

CRC errors can transpire when files are resumed too many times during the download process and as a result lose a few bytes along the way. Consequentially they become corrupt and are ultimately useless. Some of the more advanced download managers have a kind of 'roll back' function to counter this problem, which re-copies the last few bytes of a file each time it is resumed. It's also possible to choose to what extent you would like to backtrack. This is useful because the amount of data which can become corrupt upon resuming a transfer is directly proportional to the speed of your connection.

Compressed archives, or any file type for that matter, can also become corrupt if they are downloaded too fast. If your computer is unable to write data to the hard drive as quickly as it is being downloaded, some of the data can be lost. What you must ensure is that your computer is sufficiently powerful to keep up with the demands of your modem. If not, you will have to employ your download manager to impose a speed limit on your transfers.

Several different methods can be used to repair damaged archives with varying degrees of success. To access Winace's archive repair function, browse along to 'archive' then 'repair archive' within the menus at the top of the interface. Similarly, Winrar's equivalent tool can be located under the 'commands' > 'repair archive' option. Don't be surprised, however, if they both fail dismally.

The developers of Winrar, in realizing how useless these tools are, have now created a new system used to repair damaged archives and have made it available in Winrar versions 3.0 and above. It uses 'rev' files (recovery volume) to maintain a record of how to repair a given archive if it should become corrupt. These work in much the same way as 'par' files (the topic of another blog entry) and in addition to providing the means to repair damaged archives, also allow you to rebuild missing segments of archives. Rev files can be created along with the archives they are designed to rebuild providing the relevant box is ticked beforehand. If a rev file is present when extracting the archives it will automatically be used by Winrar to repair and rebuild the archives on the fly.

Nevertheless, a less sophisticated yet dependable way of ensuring that your archives are error free, is to download them again and re-test them for CRC problems. If you experience recurring errors it would be wise to download the same files from a different location.

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