Doc/lib/libtelnetlib.tex

   1 % LaTeX'ized from the comments in the module by Skip Montanaro
   2 % <skip@mojam.com>.
   3
   4 \section{\module{telnetlib} ---
   5          Telnet client}
   6
   7 \declaremodule{standard}{telnetlib}
   8 \modulesynopsis{Telnet client class.}
   9
  10
  11 The \module{telnetlib} module provides a \class{Telnet} class that
  12 implements the Telnet protocol.  See \rfc{854} for details about the
  13 protocol.
  14
  15
  16 \begin{classdesc}{Telnet}{\optional{host\optional{, port}}}
  17 \class{Telnet} represents a connection to a telnet server. The
  18 instance is initially not connected; the \method{open()} method must
  19 be used to establish a connection.  Alternatively, the host name and
  20 optional port number can be passed to the constructor, too.
  21
  22 Do not reopen an already connected instance.
  23
  24 This class has many \method{read_*()} methods.  Note that some of them
  25 raise \exception{EOFError} when the end of the connection is read,
  26 because they can return an empty string for other reasons.  See the
  27 individual descriptions below.
  28 \end{classdesc}
  29
  30
  31 \subsection{Telnet Objects \label{telnet-objects}}
  32
  33 \class{Telnet} instances have the following methods:
  34
  35
  36 \begin{methoddesc}{read_until}{expected\optional{, timeout}}
  37 Read until a given string is encountered or until timeout.
  38
  39 When no match is found, return whatever is available instead,
  40 possibly the empty string.  Raise \exception{EOFError} if the connection
  41 is closed and no cooked data is available.
  42 \end{methoddesc}
  43
  44 \begin{methoddesc}{read_all}{}
  45 Read all data until \EOF{}; block until connection closed.
  46 \end{methoddesc}
  47
  48 \begin{methoddesc}{read_some}{}
  49 Read at least one byte of cooked data unless \EOF{} is hit.
  50 Return \code{''} if \EOF{} is hit.  Block if no data is immediately
  51 available.
  52 \end{methoddesc}
  53
  54 \begin{methoddesc}{read_very_eager}{}
  55 Read everything that can be without blocking in I/O (eager).
  56
  57 Raise \exception{EOFError} if connection closed and no cooked data
  58 available.  Return \code{''} if no cooked data available otherwise.
  59 Do not block unless in the midst of an IAC sequence.
  60 \end{methoddesc}
  61
  62 \begin{methoddesc}{read_eager}{}
  63 Read readily available data.
  64
  65 Raise \exception{EOFError} if connection closed and no cooked data
  66 available.  Return \code{''} if no cooked data available otherwise.
  67 Do not block unless in the midst of an IAC sequence.
  68 \end{methoddesc}
  69
  70 \begin{methoddesc}{read_lazy}{}
  71 Process and return data already in the queues (lazy).
  72
  73 Raise \exception{EOFError} if connection closed and no data available.
  74 Return \code{''} if no cooked data available otherwise.  Do not block
  75 unless in the midst of an IAC sequence.
  76 \end{methoddesc}
  77
  78 \begin{methoddesc}{read_very_lazy}{}
  79 Return any data available in the cooked queue (very lazy).
  80
  81 Raise \exception{EOFError} if connection closed and no data available.
  82 Return \code{''} if no cooked data available otherwise.  This method
  83 never blocks.
  84 \end{methoddesc}
  85
  86 \begin{methoddesc}{open}{host\optional{, port}}
  87 Connect to a host.
  88 The optional second argument is the port number, which
  89 defaults to the standard telnet port (23).
  90
  91 Do not try to reopen an already connected instance.
  92 \end{methoddesc}
  93
  94 \begin{methoddesc}{msg}{msg\optional{, *args}}
  95 Print a debug message when the debug level is \code{>} 0.
  96 If extra arguments are present, they are substituted in the
  97 message using the standard string formatting operator.
  98 \end{methoddesc}
  99
 100 \begin{methoddesc}{set_debuglevel}{debuglevel}
 101 Set the debug level.  The higher the value of \var{debuglevel}, the
 102 more debug output you get (on \code{sys.stdout}).
 103 \end{methoddesc}
 104
 105 \begin{methoddesc}{close}{}
 106 Close the connection.
 107 \end{methoddesc}
 108
 109 \begin{methoddesc}{get_socket}{}
 110 Return the socket object used internally.
 111 \end{methoddesc}
 112
 113 \begin{methoddesc}{fileno}{}
 114 Return the file descriptor of the socket object used internally.
 115 \end{methoddesc}
 116
 117 \begin{methoddesc}{write}{buffer}
 118 Write a string to the socket, doubling any IAC characters.
 119 This can block if the connection is blocked.  May raise
 120 \exception{socket.error} if the connection is closed.
 121 \end{methoddesc}
 122
 123 \begin{methoddesc}{interact}{}
 124 Interaction function, emulates a very dumb telnet client.
 125 \end{methoddesc}
 126
 127 \begin{methoddesc}{mt_interact}{}
 128 Multithreaded version of \method{interact()}.
 129 \end{methoddesc}
 130
 131 \begin{methoddesc}{expect}{list\optional{, timeout}}
 132 Read until one from a list of a regular expressions matches.
 133
 134 The first argument is a list of regular expressions, either
 135 compiled (\class{re.RegexObject} instances) or uncompiled (strings).
 136 The optional second argument is a timeout, in seconds; the default
 137 is to block indefinately.
 138
 139 Return a tuple of three items: the index in the list of the
 140 first regular expression that matches; the match object
 141 returned; and the text read up till and including the match.
 142
 143 If end of file is found and no text was read, raise
 144 \exception{EOFError}.  Otherwise, when nothing matches, return
 145 \code{(-1, None, \var{text})} where \var{text} is the text received so
 146 far (may be the empty string if a timeout happened).
 147
 148 If a regular expression ends with a greedy match (e.g. \regexp{.*})
 149 or if more than one expression can match the same input, the
 150 results are undeterministic, and may depend on the I/O timing.
 151 \end{methoddesc}