info on channels

Where can I find some basic info on channels and how to use them with scripts? I tried the basic community search; which says they are versions of software(??). I tried WIKI which isn't much better. I tried WIKI LSL which never says anything about anything that's usable.
I get so frustrated trying to get some basic knowledge of LSL without driving all the instructors nuts. I can't even find out the proper format to enter a channel driven message into my local communication bar. - (frowns)

/1command

there are groups in world that love a good question to chat about, most of them using the word 'script' in the group name.

Kyttn, it's a forward slash followed by the channel number, a blank space and what you want to say:

"/49 hello"

(without the double quotes)

You can think of channels as sorta like radio stations.

Regular chat (people talking to each other in text) is all on channel 0. You cannot change this - when you type stuff into the chat bar, it will always go to channel 0, unless you explicitly specify a different channel.

Scripts can also listen on channel 0 and speak on channel 0. This is generally considered bad form unless you use it carefully - sending every line of chat to a bunch of scripts is expensive on the sim and scripts chatting on channel 0 can quickly get spammy.

Valid channel numbers range from around -2 billion to about 2 billion.

People can also chat on other channel numbers. Like, if you enter "/1hello" in chat, the text "hello" will go to anybody listening on channel 1.

People cannot chat on the negative channel numbers - doing "/-26hello" won't work. Scripts can listen and chat on any channel.

Regular chat goes to everything within a 20 meter diameter sphere. Whispers go to 10m, shouts go 100m. Scripts can also use llRegionSay which goes to everything in the region - the sim won't allow region says on channel 0, though.

/me hopes this helps a little.

The space between the /49 and the 'hello' is optional, BTW. Both "/49hello" and "/49 hello" will send "hello" to a script listening on channel 49.

Would that be 20m from the edges of the two prims containing the scripts or 20m on center? Also, why do people seem to prefer llRegionSay rather than llSay in the scripting tips forum?

I believe it's 20m from the center of the prim (or mouth of the avatar mesh) talking to the center of any prim containing a script listening on that channel. Haven't tested it myself but think I saw talk of this recently around here somewhere.

llSay is normal chat of 20m and llRegionSay is not volume constrained - it goes to the entire region. For scripts talking on channels that aren't heavily used like, say, channel -53452315, it's cheaper for the sim to just send it to everybody on that channel than it is for the sim to calculate a 20m sphere centered on the talking script and just sending the chat to other scripts within that sphere.

/me also pimps http://jira.secondlife.com/browse/SVC-1224, while she's here. It's a suggestion to have LL implement llParcelSay which would go to everybody/every script on a parcel.

Thanks, I think I understand that a little better.

D'oh - too slow with the edits.. Might want to reread the post above..

That was what I took before your edit. That the servers have to calculate the 20m sphere, which would cause a lot of calculations for scripts with a lot of chats. Thanks again.