Check a Website Availability from the Linux Command Line -

You can easily test a a website availability from the Linux command line and get the status codes from the web-server using commands like TELNET or CURL.

Check a website availability with CURL

Execute the following command to check whether a web site is up, and what status message the web server is showing:

$ curl -Is http://www.shellhacks.com | head -1
HTTP/1.1 200 OK

Status code ‘200 OK’ means that the request has succeeded and a website is reachable.

Here is an another example that shows you how curl displays different status codes.

$ curl -Is http://shellhacks.com | head -n 1
HTTP/1.1 301 Moved Permanently

You’ll notice that if you visit: http://shellhacks.com you are redirected to http://www.shellhacks.com, because I prefer to have www in my site’s URL. I do this by implementing a 301 Redirect (Permanently moved) for any visitor who goes to http://shellhacks.com.

You can also check the availability of a particular page on the site:

$ curl -Is http://www.shellhacks.com/en/Bash-Colors | head -n 1
HTTP/1.1 200 OK

Check a website availability with TELNET

You can also test website availability and get the response code using telnet command:

$ telnet www.shellhacks.com 80
Trying 91.206.200.119...
Connected to www.shellhacks.com.
Escape character is '^]'.
HEAD / HTTP/1.0
HOST: www.shellhacks.com
<PRESS ENTER>
<PRESS ENTER>

You will get the output as follows:

HTTP/1.1 200 OK
Server: nginx/1.1.10
Date: Sun, 26 May 2013 19:29:46 GMT
***

That also means that the website is OK.