semi-colon ";" in rdata for TXT records

[Barry Margolin]

In article <fdqki7$le6$1 at sf1.isc.org>,
 "Jack Tavares" <j.tavares at F5.com> wrote:

> Hello all -
>  
> I am having a small problem.
>  
> Given these 2 TXT records in a zone file
> isescaped                       TXT     "escaped semi-colon\;"
> unescaped                       TXT     "unescaped semi-colon;"
> (one has an escaped semi-colon, one has an UNescaped semi-colon)
>  
> dig returns
>  
> isescaped.test.net.     500     IN      TXT     "escaped semi-colon\;"
> unescaped.test.net.     500     IN      TXT     "unescaped semi-colon\;"
> 
> dig makes sure that the semi-colon is escaped for output purposes.
>  
> Now I have another tool, written in C/C++ that calls ns_sprintrr (from
> libbind.a)
> This does include the "\" before the semi-colon on EITHER TXT record

That's because both TXT records are essentially the same in that regard.  
The last two characters of both are "n" and semicolon.

Semicolons don't require escaping when they're in quoted strings, but 
it's OK to escape them anyway.  A backslash simply causes the following 
character to be treated as a constituent of the string.  If that's its 
normal meaning, the backslash is ignored.  I think the only characters 
that REQUIRE escaping in strings are double-quote (to prevent it from 
terminating the string) and backslash itself (to prevent it from being 
an escape).  Maybe newline as well, but I'm not sure.

>  
> I have 2 questions:
>  
> 1. is the "\" (slash) included in the wire format or is it stripped out?

It isn't.  The wire syntax is a counted string.  There's no parsing 
done, so no need for any escaping.

> 2. what routine is dig using to print the record?

Can't you read the source?

Did you mean to say 'This does NOT include the "\"' above?

-- 
Barry Margolin, barmar at alum.mit.edu
Arlington, MA
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