Chebucto Community Net:
IP FAQs: Hyperlink Verification
One of the great strengths of the World Wide Web (WWW) is its ability
to form hyperlinks to other materials and other sites throughout the
breadth, not only of the WWW but across the Internet to Gopher, Usenet,
EMail, FTP, Telnet and other resources. Many websites incorporate
hyperlinks (employing the HTML anchor element, <A HREF="etc">) to
other sites.
Having done so, the issue of maintaining and administering these links
arises. The WWW is a very dynamic place and sites and materials are
forever being relocated or closed. Domain names change and servers go in
and out of service. How do you keep up?
It's very important to keep your links as current as possible. It's a
great disservice to users to have a list of links to interesting materials
only to have half of them not working or pointing to redirect flags!
While there is no substitute to checking them yourself on a periodic
basis, there is, however, a useful utility which can expedite this is a
site called:
Hyperlink Verification
This is a useful verification engine. What you do is specify a URL (say of
a page in your website where you have a number of links) and an EMail
address to reach you. Hyperlink Verification then goes away and tests all
the links on the page and EMails you a report of their status. Typically
it classified the URLs it has evaluated into one of 4 categories:
- OK - it reached some page of information
- Not Found - it could not find any page of information
- Timed Out - it waited for a response for a certain period of time and
received none.
- Connection Failed - it was unable to establish a connection with the
specified server
- Not Checked - it did not check the link for reasons of its own
- Bad Request - ? - uncertain what this indicates
You can then use these results to determine if you should do some further
research or investigation. Any link that reports back as Not Found
or Connection Failed merits immediate attention. For whatever
reason, that material is no longer at the address specified by your
link.
A connection which Timed Out also deserves attention. It could be
that Network connections were slow, or that the server at the other end
happened to be out of service, but it could also mean that the server no
longer exists. If you are unable to connect to this server after repeated
trials you need to take further action to determine if the site still
exists, and if so where.
You should also check all URLs that Hyperlink Verification could not, or
did not, check itself to ensure that they are functioning.
An important point to remember is that when Hyperlink Verification reports
back that a URL is OK this simply means that it reached some
page of information at the end of a URL. This page could be the right page
(i.e. the one you intended) or it could be a re-direct flag which informs
users that the site has moved. It could even be the wrong page if you have
incorrectly specified it in your URL. Thus, Internet robots can only do so
much -- there is no better way to test links than to evaluate them
periodically yourself!
Finally, note that Hyperlink Verification will verify only HTTP links. It
will not investigate Gopher, WAIS, Telnet, FTP, News or EMail links. These
need to be checked via other means.
[N.B. Please note that Hyperlink Verification is not a CCN utility but is
a service provided by End
User Computing Ltd. in the United Kingdom.]
For further questions on the use of this resource, EMail ip-help@chebucto.ns.ca
Christopher Majka