To use a template when creating another section, simply put the template name in parentheses after the section heading name, as shown in the example below. If you want to inherit from multiple templates, use commas to separate the template names).
[template-name](!) setting=value [template-2](!) setting2=value2 [not-a-template] setting4=value4 [section-name](template-name,template-2,not-a-template) setting3=value3
This works even when the section name referenced in parentheses is not defined as a template as in the case of the "not-a-template" section.
The newly-created section will inherit all the values and objects defined in the template(s), as well as any new settings or objects defined in the newly-created section. The settings and objects defined in the newly-created section override settings or objects of the same name from the templates. Consider this example:
[test-one](!) permit=192.168.0.2 host=alpha.example.com deny=192.168.0.1 [test-two](!) permit=192.168.1.2 host=bravo.example.com deny=192.168.1.1 [test-three](test-one,test-two) permit=192.168.3.1 host=charlie.example.com
The [test-three] section will be processed as though it had been written in the following way:
[test-three] permit=192.168.0.2 host=alpha.example.com deny=192.168.0.1 permit=192.168.1.2 host=bravo.example.com deny=192.168.1.1 permit=192.168.3.1 host=charlie.example.com
chan_sip Template Example
Here is a more extensive and realistic example from the chan_sip channel driver's sample configuration file.
[basic-options](!) ; a template dtmfmode=rfc2833 context=from-office type=friend [natted-phone](!,basic-options) ; another template inheriting basic-options nat=yes directmedia=no host=dynamic [public-phone](!,basic-options) ; another template inheriting basic-options nat=no directmedia=yes [my-codecs](!) ; a template for my preferred codecs disallow=all allow=ilbc allow=g729 allow=gsm allow=g723 allow=ulaw [ulaw-phone](!) ; and another one for ulaw-only disallow=all allow=ulaw ; and finally instantiate a few phones ; ; [2133](natted-phone,my-codecs) ; secret = peekaboo ; [2134](natted-phone,ulaw-phone) ; secret = not_very_secret ; [2136](public-phone,ulaw-phone) ; secret = not_very_secret_either