Python CGI script to display client's IP address

madphilosopher (Darren Paul Griffith) — Tue, 04 Apr 2006 19:54:21 GMT

When run as a cgi script, this will print the client's IP address.



import cgi

import os



print "Content-type: text/html"

print ""



print cgi.escape(os.environ["REMOTE_ADDR"])

Create VIPs on Mac OSX

rtomayko (Ryan Tomayko) — Sun, 25 Sep 2005 13:41:11 GMT

Virtual IPs are so damn useful it hurts sometimes. On Mac OS X 10.1 and above, they're extremely easy to create:

Create a VIP on the same subnet as the primary interface(netmask must be 0xFFFFFFFF):



# ifconfig en1 inet 192.168.1.130 netmask 255.255.255.255 alias

Create a VIP on a different subnet:



# ifconfig en1 inet 192.168.64.25 netmask 255.255.255.0 alias

(Note: you may have to sub en0 for en1. Use ifconfig -a to find out what interfaces are available)

Now you have another IP that you can bring stuff up on that won't collide with other stuff running on the same port.

This is in no way limited to Rails but we can use it to illustrate. Create a VIP for 192.168.1.150 using the ifconfig command above. Then add a line to your /etc/hosts file as follows:



192.168.1.150  myapp

Now bring Rails up bound to that address on port 80:



$ cd devel/myapp

$ ./script/server -b myapp -p 80

http://myapp/ should now be on Rails.

DZone Snippets: networking code

Python CGI script to display client's IP address

Create VIPs on Mac OSX