This process is called Web crawling or spidering. Many sites, in particular search engines, use spidering as a means of providing up-to-date data. Web crawlers are mainly used to create a copy of all the visited pages for later processing by a search engine that will index the downloaded pages to provide fast searches. Crawlers can also be used for automating maintenance tasks on a Web site, such as checking links or validating HTML code. Also, crawlers can be used to gather specific types of information from Web pages, such as harvesting e-mail addresses (usually for spam).
A Web crawler is one type of bot, or software agent. In general, it starts with a list of URLs to visit, called the seeds. As the crawler visits these URLs, it identifies all the hyperlinks in the page and adds them to the list of URLs to visit, called the crawl frontier. URLs from the frontier are recursively visited according to a set of policies.
]]>If you guys have any suggestions, please let me know.
]]>What do you use to keep warm?
- I have a mummy sleeping bag for the nights.
What do you sleep on?
- I did have an air bed, but this requires pumping up three times a week. Would one of those rolly mats really suffice? Or should I look at a proper bed that stands 5/10cm above the ground?
What sort of tent do you have?
- I did have a 3 man tent (to myself) but this time round, I’ll go for another 3 man, btu one that maybe has a bit of a porch area too.