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Alright... here I am, trying to run various codebases on my Cygwin box.. i really need to get linux but i dont have the authority to partition my hard drive, and my laptop and any other computers where i might install it are old enough that my computer-smart friend tells me they wouldn't be able to run it.

OK. So here's the scoop on this. I've got cygwin running on an oldish, but not THAT old, windows computer. Using Dystopia 1.2... i'm getting an error thus:

comm.o(.text+0x12f3):comm.c: undefined reference to `_gethostbyaddr_r'
collect2: ld returned 1 exit status
make: *** [merc] Error 1

I'm guessing that, since using grep i find that gethostbyaddr is only called and never defined, it's part of some Linux-ish library that I dont have. Is there somewhere I missed. i'm pondering deleting and reinstalling cygwin cause there's a new version out. Advice?

and my laptop and any other computers where i might install it are old enough that my computer-smart friend tells me they wouldn't be able to run it

I find that comment odd. I ran and developed a Circle mud on Linux that at the time had 30-50 players most of the time, on a 486DX2-66. Are your computers that old?

/Fredrik

You can run a non-x-windowed version of the Linux 2.4 kernel on a freakin' Commodore 64. I've even seen an article in a magazine which showed you how to modify an X-Box to run Linux, even down to how to add keyboard and mouse support (http://xbox-linux.sourceforge.net/docs/gettingstarted.html). Linux will run on just about anything short of a calculator.
I've seen Linux run on old PDA's for Christ's sake.
If your friends say they are too old, I would have to say that if they can boot up and have CD-ROM support, your friends are wrong.

gethostbyaddr is a function used to do a DNS lookup, e.g. to turn "www.microsoft.com" into 206.65.174.32. It's a standard function in most Unix implementations. It looks like your compiler has found the header file for it (otherwise you'd have had a compiler warning about it in comm.c), but the linker can't find the actualy library containing the code for the function.

Possibly you need to install another library into Cygwin, or you might just need change the Makefile to tell it to link against the appropriate library.



(Comment added by Genghis on Mon Nov 24 7:21:02 2003)

Sorry, it does a reverse DNS lookup, giving you "www.microsoft.com" when you provide it 206.65.174.32. Useful for knowing where someone connecting to your mud comes from.

It's a standard function in most Unix implementations.

gethostbyaddr may be, but gethostbyaddr_r is not. And even when available the function has almost as many signatures as there are Unices.

Or just skip the whole dns lookup and use ntohl to get the numeric address. Can always use whois

when bored.

(Comment added by scandum on Mon Nov 24 15:51:18 2003)

whois [address] that was

>gethostbyaddr may be, but gethostbyaddr_r is not. And even when available the function has almost as many signatures as there are Unices.

True. Honestly, the best solution is just to use gethostbyaddr (OP: if you need info on how to use gethostbyaddr, we'll provide it) and make sure it's not called by two threads -which is easy enough and more importantly, which should be the case already anyway in a good design.

.

Doh, didn't even notice that "_r", my subconscious just wrote it off as some kind of bizarre C++ name mangling and promptly ignored it :)