Possible to “ping” url:port? (OS X-GeekTool)

Question

I'm trying to use GeekTool (Mac pref pane... basically just embeds output of a shell command/script on the desktop... http://lifehacker.com/#!244026/geek-to-live--monitor-your-mac-and-more-with-geektool) to monitor a a remote machines/server, and I'm having some trouble determining how best to check if a machine is up/down.

I'm using no-ip as a free dns re-direct... but this only helps me with the public IP of the router. The machine I want is behind the router and thus isn't able to be "ping"ed directly.

I have port forwarding set up for port 8080 which leads to the machine I want. Is there a way to essentially ping through port 8080 to see if the machine is up and running? I tried telnet, but this apparently doesn't work (as far as output) in GeekTool. I'm running a website at 8080, so I guess I just want to know if/when it goes down.

Thanks in advance... if I can provide more clarification let me know.

(figured out my problem... see below)

Answer 1

To check a specific port, you can use telnet:

telnet 127.0.0.1 8080

(The port follows the IP / hostname with a space, not a colon.)

If you get an immediate error, then the port is not available. If telnet hangs, then you have successfully connected to the port. Ctrl + C to kill telnet, then.

This may or may not help with the port forwarding issue, though. It just gets you to that IP and port.

Answer 2

You could use wget, curl etc. to check that the website is responding.

Answer 3

Telnet gets the job done, but I'm unable to integrate that with GeekTool. I ended up doing a mysqladmin ping to the remote machine. The website has a db backend, so this (more-or-less) returns the info I'm looking for. Thanks for all the help!