Ludovic Gasc
2015-Jun-28 13:40 UTC
[asterisk-users] Asterisk dialplan best practices syntax
2015-06-26 17:11 GMT+02:00 Steve Edwards <asterisk.org at sedwards.com>:> On Fri, 26 Jun 2015, Ludovic Gasc wrote: > > 1. What's the "official" notation of each line: "=>" or "=" ? In the wiki >> of Asterisk, I see very often "=>", however, what's the reason for both >> syntaxes authorized ? Historical ? >> > > I'm not 'official,' but I have a strong preference for just '=.' Using > '=>' seems clunky, ugly, and unnecessary.It's interesting because from my point of view, I prefer to use '=>', because, to me, '=' is for config files. The dialplan is a programming language, not a config file. If you like buzzwords, it's a Domain Specific Language. However, it's completely a religious point of view, Asterisk will process exactly the same dialplan with '=' or with '=>'. I was interested in by the story that will explain to me why Asterisk support both syntaxes, if somebody remembers. Thank you Steve for your answers in point 2., any tips to improve readability of dialplan is interesting to me. 2. To write info in logs/console, you have two commands: NoOp and Verbose.>> Verbose seems to be better, because you can define a log level. Are you >> agree or another command fits better for logs ? >> > > This is kind of a pet peeve of mine. Why use the misguided 'side effect' > of an application when there is a specific, 'more featured,' application > for that purpose? A 'noop' is a contraction of 'no operation' meaning it > should do nothing but act as a placeholder. > > Two other areas of 'best practices' I'm a strong believer in are: > alphabetize wherever possible, and use white space to improve readability. > > For example, here's a 'sanitized' sip.conf snippet from a popular > provider's web site: > > [xxx-inbound] > type=friend > dtmfmode=auto > host=xxx.yyy.zzz > context=inbound > > username=xxx > secret=yyy > > allow=all > insecure=port,invite > canreinvite=no > > [xxx-outbound] > type=friend > dtmfmode=auto > host=xxx.yyy.zzz > username=xxx > fromuser=xxx > secret=xxx > trustrpid=yes > sendrpid=yes > allow=all > canreinvite=no > > Pretty ugly and difficult to read. With a little whitespace and > alphabetizing we get: > > [xxx-inbound] > allow = all > canreinvite = no > context = inbound > dtmfmode = auto > host = xxx.yyy.zzz > insecure = port,invite > secret = yyy > type = friend > username = xxx > > [xxx-outbound] > allow = all > canreinvite = no > dtmfmode = auto > fromuser = xxx > host = xxx.yyy.zzz > secret = xxx > sendrpid = yes > trustrpid = yes > type = friend > username = xxx > > Now, the major sections are easy to 'visually delineated.' Finding the > 'secret' is much easier now. Comparing a 'working' extension with a > 'broken' extension will be much easier as well. > > I use the same formatting in the dialplan. This snippet is from > extensions.conf.sample: > > [outbound-freenum2] > exten => _X!,1,Verbose(2,Performing ISN lookup for ${EXTEN}) > same => n,Set(SUFFIX=${CUT(EXTEN,*,2-)}) > same => n,GotoIf($["${FILTER(0-9,${SUFFIX})}" !> "${SUFFIX}"]?fn-CONGESTION,1) > same => n,Set(TIMEOUT(absolute)=10800) > same => n,Set(isnresult=${ENUMLOOKUP(${EXTEN},sip,,1,freenum.org)}) > same => n,GotoIf($["${isnresult}" != ""]?from) > same => n,Set(DIALSTATUS=CONGESTION) > same => n,Goto(fn-CONGESTION,1) > same => n(from),Set(__SIPFROMUSER=${CALLERID(num)}) > same => n,GotoIf($["${GLOBAL(FREENUMDOMAIN)}" = ""]?dial) > same => n,Set(__SIPFROMDOMAIN=${GLOBAL(FREENUMDOMAIN)}) > same => n(dial),Dial(SIP/${isnresult},40) > same => n,Goto(fn-${DIALSTATUS},1) > > exten => fn-BUSY,1,Busy() > > exten => _f[n]-.,1,NoOp(ISN: ${DIALSTATUS}) > same => n,Congestion() > > With a little whitespace, this becomes much more readable: > > [outbound-freenum2] > exten = _X!,1, Verbose(2,Performing ISN lookup > for ${EXTEN}) > same = n, Set(SUFFIX=${CUT(EXTEN,*,2-)}) > same = n, > GotoIf($["${FILTER(0-9,${SUFFIX})}" != "${SUFFIX}"]?fn-CONGESTION,1) > same = n, Set(TIMEOUT(absolute)=10800) > same = n, > Set(isnresult=${ENUMLOOKUP(${EXTEN},sip,,1,freenum.org)}) > same = n, GotoIf($["${isnresult}" !> ""]?from) > same = n, Set(DIALSTATUS=CONGESTION) > same = n, Goto(fn-CONGESTION,1) > same = n(from), Set(__SIPFROMUSER=${CALLERID(num)}) > same = n, > GotoIf($["${GLOBAL(FREENUMDOMAIN)}" = ""]?dial) > same = n, > Set(__SIPFROMDOMAIN=${GLOBAL(FREENUMDOMAIN)}) > same = n(dial), Dial(SIP/${isnresult},40) > same = n, Goto(fn-${DIALSTATUS},1) > > exten = fn-BUSY,1, Busy() > > exten = _f[n]-.,1, NoOp(ISN: ${DIALSTATUS}) > same = n, Congestion() > > Compare the effort to find where the 'dial' is in the 'before' and 'after.' > > -- > Thanks in advance, > ------------------------------------------------------------------------- > Steve Edwards sedwards at sedwards.com Voice: +1-760-468-3867 PST > Newline Fax: +1-760-731-3000 > > -- > _____________________________________________________________________ > -- Bandwidth and Colocation Provided by http://www.api-digital.com -- > New to Asterisk? Join us for a live introductory webinar every Thurs: > http://www.asterisk.org/hello > > asterisk-users mailing list > To UNSUBSCRIBE or update options visit: > http://lists.digium.com/mailman/listinfo/asterisk-users >-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.digium.com/pipermail/asterisk-users/attachments/20150628/b0bea63e/attachment.html>
Steve Edwards
2015-Jun-28 15:08 UTC
[asterisk-users] Asterisk dialplan best practices syntax
On Sun, 28 Jun 2015, Ludovic Gasc wrote:> It's interesting because from my point of view, I prefer to use '=>', > because, to me, '=' is for config files. The dialplan is a programming > language, not a config file.The only language I'm familiar with (I'm primarily a 'c' guy) that uses '=>' is PHP. In PHP, '=>' is used with associative arrays. I tend to think of a dialplan as a group of one dimensional linear arrays with the name of the array being the context concatenated with the exten so for me, a simple assignment makes sense. -- Thanks in advance, ------------------------------------------------------------------------- Steve Edwards sedwards at sedwards.com Voice: +1-760-468-3867 PST Newline Fax: +1-760-731-3000
Tech Support
2015-Jun-28 16:11 UTC
[asterisk-users] Asterisk dialplan best practices syntax
Hey; Don't forget Perl. I'm not sure what everyone else calls it, but most Perl programmers call it a "fat comma". From Chromatic's "Modern Perl" book: One of the simplest but most useful examples of TIMTOWTDI in the design of Perl is the fat comma operator (=>), which acts like a regular comma except that it automatically quotes barewords used as its left operands. It also looks like an arrow, so it leads from left to right and implies a stronger association between its operands than the normal comma does. You can see this in hash initializers: my %dogs = ( alpha => 'Rodney', clown => 'Lucky', puppy => 'Rosie', ); Regards; John V. -----Original Message----- From: asterisk-users-bounces at lists.digium.com [mailto:asterisk-users-bounces at lists.digium.com] On Behalf Of Steve Edwards Sent: Sunday, June 28, 2015 11:08 AM To: Asterisk Users Mailing List - Non-Commercial Discussion Subject: Re: [asterisk-users] Asterisk dialplan best practices syntax On Sun, 28 Jun 2015, Ludovic Gasc wrote:> It's interesting because from my point of view, I prefer to use '=>', > because, to me, '=' is for config files. The dialplan is a programming > language, not a config file.The only language I'm familiar with (I'm primarily a 'c' guy) that uses '=>' is PHP. In PHP, '=>' is used with associative arrays. I tend to think of a dialplan as a group of one dimensional linear arrays with the name of the array being the context concatenated with the exten so for me, a simple assignment makes sense. -- Thanks in advance, ------------------------------------------------------------------------- Steve Edwards sedwards at sedwards.com Voice: +1-760-468-3867 PST Newline Fax: +1-760-731-3000 -- _____________________________________________________________________ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- New to Asterisk? Join us for a live introductory webinar every Thurs: http://www.asterisk.org/hello asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users