Automatic DHCP renew on Mac

I would like a command line C program that will perform a DHCP renew on all active LAN-based network interfaces. The program should also be able to accept an IP address as an argument, and perform the DHCP renew only on the interface that has the specified IP address. This program will be run on a Macintosh with Mac OS X. In addition to the C program, a script that provides identical functionality and uses the same syntax as the C program may be required. The script should be written using a language available on all versions of Mac OS X. This should be bid as an optional component if it adds substantially to the cost. Firstly, the program should parse through the entire list of network interfaces using TCP/IP. Interfaces like loopback, dial-up, VPN, or interfaces without media connected should be ignored. The program should then perform the renew operation on all remaining interfaces. I found that the shell command "ipconfig set DHCP" to be effective in initiating the DHCP renew, but am open to other methods as well if they are as effective. Syntax: The program can only be run with zero or 1 argument. The only acceptable argument would be a 4-byte IP address in dotted decimal notation. If the program is called with zero arguments, then it should perform the DHCP renew on all interfaces as specified in the requirements previously stated. If the program is called with one argument, then the DHCP renew should only be performed on the interface which uses the IP address supplied in the argument. Please provide the C function and a program and makefile sample utility that calls this function as well as the equivalent script. ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. Programs must be tested to work properly. Software should be tested on as many Mac OS X versions as possible, but definitely on Mac OS X 10.3 and 10.4. If you can test on more platforms, please indicate so on your bid. 2) Deliverables must be in ready-to-run condition, as follows (depending on the nature of the deliverables): a) For web sites or other server-side deliverables intended to only ever exist in one place in the Buyer's environment--Deliverables must be installed by the Seller in ready-to-run condition in the Buyer's environment. b) For all others including desktop software or software the buyer intends to distribute: A software installation package that will install the software in ready-to-run condition on the platform(s) specified in this bid request. 3) All deliverables will be considered "work made for hire" under U.S. Copyright law. Buyer will receive exclusive and complete copyrights to all work purchased. (No GPL, GNU, 3rd party components, etc. unless all copyright ramifications are explained AND AGREED TO by the buyer on the site per the coder's Seller Legal Agreement). ## Platform Mac OS X 10.3 and 10.4. In addition, other versions of Mac OS X is highly desirable.