Where is it detailed about extensions.conf in Asterisk?

Question

Asterisk

Good afternoon.
I'm learning Asterisk. I'm already approaching zero in it, but still in the red.
Please tell me where you can read in detail about the exten commands from extensions.conf?
Found on wiki.dieg.info/extensions.conf, is there anything else?
It is desirable to format a command that does and an example of work.
There is a lot of information on the Internet, but all of it, in my opinion, does not have a clear structure. Maybe I'm not looking there?
Many thanks in advance to everyone who answered and poked my nose in the right direction!

Answer 1

Hello
There is a good book: Asterisk The Future of Telephony
Everything is simply and clearly described in it

Answer 2

Did you build Asterisk from source?
make samples - will generate a bunch of files for you, including extensions.conf with examples and descriptions.

Answer 3

In the Asterisk console

> core show applications
> core show application ...
> core show functions
> core show function ...

Answer 4

I will leave the link www.asteriskforum.ru/download.php?id=522&sid=210b5...

Answer 5

xgu.ru/wiki/Asterisk
asterisk.ru/knowledgebase/Asterisk+config+extensio...