Doc/mac/libmacdnr.tex

   1 \section{\module{macdnr} ---
   2          Interface to the Macintosh Domain Name Resolver}
   3
   4 \declaremodule{builtin}{macdnr}
   5   \platform{Mac}
   6 \modulesynopsis{Interfaces to the Macintosh Domain Name Resolver.}
   7
   8
   9 This module provides an interface to the Macintosh Domain Name
  10 Resolver.  It is usually used in conjunction with the \refmodule{mactcp}
  11 module, to map hostnames to IP addresses.  It may not be available in
  12 all Mac Python versions.
  13 \index{Macintosh Domain Name Resolver}
  14 \index{Domain Name Resolver, Macintosh}
  15
  16 The \module{macdnr} module defines the following functions:
  17
  18
  19 \begin{funcdesc}{Open}{\optional{filename}}
  20 Open the domain name resolver extension.  If \var{filename} is given it
  21 should be the pathname of the extension, otherwise a default is
  22 used.  Normally, this call is not needed since the other calls will
  23 open the extension automatically.
  24 \end{funcdesc}
  25
  26 \begin{funcdesc}{Close}{}
  27 Close the resolver extension.  Again, not needed for normal use.
  28 \end{funcdesc}
  29
  30 \begin{funcdesc}{StrToAddr}{hostname}
  31 Look up the IP address for \var{hostname}.  This call returns a dnr
  32 result object of the ``address'' variation.
  33 \end{funcdesc}
  34
  35 \begin{funcdesc}{AddrToName}{addr}
  36 Do a reverse lookup on the 32-bit integer IP-address
  37 \var{addr}.  Returns a dnr result object of the ``address'' variation.
  38 \end{funcdesc}
  39
  40 \begin{funcdesc}{AddrToStr}{addr}
  41 Convert the 32-bit integer IP-address \var{addr} to a dotted-decimal
  42 string.  Returns the string.
  43 \end{funcdesc}
  44
  45 \begin{funcdesc}{HInfo}{hostname}
  46 Query the nameservers for a \code{HInfo} record for host
  47 \var{hostname}.  These records contain hardware and software
  48 information about the machine in question (if they are available in
  49 the first place).  Returns a dnr result object of the ``hinfo''
  50 variety.
  51 \end{funcdesc}
  52
  53 \begin{funcdesc}{MXInfo}{domain}
  54 Query the nameservers for a mail exchanger for \var{domain}.  This is
  55 the hostname of a host willing to accept SMTP\index{SMTP} mail for the
  56 given domain.  Returns a dnr result object of the ``mx'' variety.
  57 \end{funcdesc}
  58
  59
  60 \subsection{DNR Result Objects \label{dnr-result-object}}
  61
  62 Since the DNR calls all execute asynchronously you do not get the
  63 results back immediately.  Instead, you get a dnr result object.  You
  64 can check this object to see whether the query is complete, and access
  65 its attributes to obtain the information when it is.
  66
  67 Alternatively, you can also reference the result attributes directly,
  68 this will result in an implicit wait for the query to complete.
  69
  70 The \member{rtnCode} and \member{cname} attributes are always
  71 available, the others depend on the type of query (address, hinfo or
  72 mx).
  73
  74
  75 % Add args, as in {arg1, arg2 \optional{, arg3}}
  76 \begin{methoddesc}[dnr result]{wait}{}
  77 Wait for the query to complete.
  78 \end{methoddesc}
  79
  80 % Add args, as in {arg1, arg2 \optional{, arg3}}
  81 \begin{methoddesc}[dnr result]{isdone}{}
  82 Return \code{1} if the query is complete.
  83 \end{methoddesc}
  84
  85
  86 \begin{memberdesc}[dnr result]{rtnCode}
  87 The error code returned by the query.
  88 \end{memberdesc}
  89
  90 \begin{memberdesc}[dnr result]{cname}
  91 The canonical name of the host that was queried.
  92 \end{memberdesc}
  93
  94 \begin{memberdesc}[dnr result]{ip0}
  95 \memberline{ip1}
  96 \memberline{ip2}
  97 \memberline{ip3}
  98 At most four integer IP addresses for this host.  Unused entries are
  99 zero.  Valid only for address queries.
 100 \end{memberdesc}
 101
 102 \begin{memberdesc}[dnr result]{cpuType}
 103 \memberline{osType}
 104 Textual strings giving the machine type an OS name.  Valid for ``hinfo''
 105 queries.
 106 \end{memberdesc}
 107
 108 \begin{memberdesc}[dnr result]{exchange}
 109 The name of a mail-exchanger host.  Valid for ``mx'' queries.
 110 \end{memberdesc}
 111
 112 \begin{memberdesc}[dnr result]{preference}
 113 The preference of this mx record.  Not too useful, since the Macintosh
 114 will only return a single mx record.  Valid for ``mx'' queries only.
 115 \end{memberdesc}
 116
 117 The simplest way to use the module to convert names to dotted-decimal
 118 strings, without worrying about idle time, etc:
 119
 120 \begin{verbatim}
 121 >>> def gethostname(name):
 122 ...     import macdnr
 123 ...     dnrr = macdnr.StrToAddr(name)
 124 ...     return macdnr.AddrToStr(dnrr.ip0)
 125 \end{verbatim}