So, who's ever looked through all the weird and wacky vars we hand into the m4 processor, that you can use to do unnatural things to your config?
There are 3 hostnames we pass in. One is CLIENTHOST, which is the machine where ctwm is running. That come out of gethostname(3), which is just getting the system's hostname. Straightforward. The second is SERVERHOST, which is the machine where the X server is running. We get that by poking through $DISPLAY and finding a hostname there (or using a copy of CLIENTHOST, if that's a local-ish thing like ":0" or the like, which probably covers 99.99% of actual running systems nowadays). OK; no problems here. But then there's HOSTNAME. What the heck. The manual says "The canonical hostname running the clients", which tells... absolutely thing. It winds up happening via calling gethostbyname(3) on CLIENTHOST, and then pulling the h_name out of the response. Well, what is that? That's probably going to vary depending on the system, and just where the response comes from. Maybe it comes from the hosts file? Then I think it's the first entry on the line, so maybe it can be considered the more 'real' name of the system, when its hostname is set to an alias of that (what? why? who cares?). Or then there's DNS, which from what I can tell means it may be transformed by 'domain' or 'search' directives in resolv.conf? After getting a response, anyway. Or <something else> happens if the lookup winds up going via NIS. Whatever other resolution methods it may use. And if it doesn't get a name from any of those, it just quietly falls back to using CLIENTHOST verbatim anyway. Ever had a system where [re]starting ctwm bizarrely pauses for a dozen seconds or so? Guess what; this is why. We block startup on [potentially] doing a DNS lookup of the client's configured hostname. So if you don't have working DNS, or have a hostname that's not in DNS (especially one that would be off in a DNS tree that purportedly exists with unreachable nameservers, so we have to wait on timeouts), twiddle your thumbs a while. Does that add enough value to be worth having that block-y a thing in the startup path? Or should I just dump it over the side into deep water, and just leave HOSTNAME as a copy of CLIENTHOST? (yeah, I'll bet you thought I was through with cackling over my keyboard looking for things to break... gotcha!) -- Matthew Fuller (MF4839) | fulle...@over-yonder.net Systems/Network Administrator | http://www.over-yonder.net/~fullermd/ On the Internet, nobody can hear you scream.
