From the command line, what’s an easy way to test that a web page is up and displaying the content you expect? It could be that you need to write a monitoring script to check a remote site, or you just want to quickly ascertain whether you can access the internet from the command line, from wherever you’re logged in. wget is a great little tool for the job.
The wget tool is a wonderful Swiss-army knife for command line web browsing. It’s frequently used for recursively grabbing entire sites and their contents, but it can also be used as a very lightweight means of querying the web.
-O switch indicates an output filename, but adding “-” to this will just send the contents of the page to the standard output. From here, you can use a pipe and redirect wget into your favourite pattern matching utility.
# wget -O - http://www.example.com/statuspage.html | grep OK
Where “OK” could be any text pattern known to appear on the web page.
Or, if it’s an HTTPS page, ignore the certificate so you don’t get a pesky error:
# wget -O - --no-check-certficiate - https://secure.example.com/status.html | grep OK
The extensive man page discusses further uses for this wonderful utility. Enjoy the read.
Matt Parsons is a freelance Linux specialist who has designed, built and supported Unix and Linux systems in the finance, telecommunications and media industries.
He lives and works in London.