summaryrefslogtreecommitdiffstats
path: root/Doc/lib/libtelnetlib.tex
blob: f28833ee2951e837f50f77d8f93df735fc5bb832 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
% LaTeX'ized from the comments in the module by Skip Montanaro
% <skip@mojam.com>.

\section{\module{telnetlib} ---
         Telnet client}

\declaremodule{standard}{telnetlib}
\modulesynopsis{Telnet client class.}


The \module{telnetlib} module provides a \class{Telnet} class that
implements the Telnet protocol.  See \rfc{854} for details about the
protocol.


\begin{classdesc}{Telnet}{\optional{host\optional{, port}}}
\class{Telnet} represents a connection to a telnet server. The
instance is initially not connected; the \method{open()} method must
be used to establish a connection.  Alternatively, the host name and
optional port number can be passed to the constructor, too.

Do not reopen an already connected instance.

This class has many \method{read_*()} methods.  Note that some of them 
raise \exception{EOFError} when the end of the connection is read,
because they can return an empty string for other reasons.  See the
individual descriptions below.
\end{classdesc}


\subsection{Telnet Objects \label{telnet-objects}}

\class{Telnet} instances have the following methods:


\begin{methoddesc}{read_until}{expected\optional{, timeout}}
Read until a given string is encountered or until timeout.

When no match is found, return whatever is available instead,
possibly the empty string.  Raise \exception{EOFError} if the connection
is closed and no cooked data is available.
\end{methoddesc}

\begin{methoddesc}{read_all}{}
Read all data until \EOF{}; block until connection closed.
\end{methoddesc}

\begin{methoddesc}{read_some}{}
Read at least one byte of cooked data unless \EOF{} is hit.
Return \code{''} if \EOF{} is hit.  Block if no data is immediately
available.
\end{methoddesc}

\begin{methoddesc}{read_very_eager}{}
Read everything that can be without blocking in I/O (eager).

Raise \exception{EOFError} if connection closed and no cooked data
available.  Return \code{''} if no cooked data available otherwise.
Do not block unless in the midst of an IAC sequence.
\end{methoddesc}

\begin{methoddesc}{read_eager}{}
Read readily available data.

Raise \exception{EOFError} if connection closed and no cooked data
available.  Return \code{''} if no cooked data available otherwise.
Do not block unless in the midst of an IAC sequence.
\end{methoddesc}

\begin{methoddesc}{read_lazy}{}
Process and return data already in the queues (lazy).

Raise \exception{EOFError} if connection closed and no data available.
Return \code{''} if no cooked data available otherwise.  Do not block
unless in the midst of an IAC sequence.
\end{methoddesc}

\begin{methoddesc}{read_very_lazy}{}
Return any data available in the cooked queue (very lazy).

Raise \exception{EOFError} if connection closed and no data available.
Return \code{''} if no cooked data available otherwise.  This method
never blocks.
\end{methoddesc}

\begin{methoddesc}{open}{host\optional{, port}}
Connect to a host.
The optional second argument is the port number, which
defaults to the standard telnet port (23).

Do not try to reopen an already connected instance.
\end{methoddesc}

\begin{methoddesc}{msg}{msg\optional{, *args}}
Print a debug message when the debug level is \code{>} 0.
If extra arguments are present, they are substituted in the
message using the standard string formatting operator.
\end{methoddesc}

\begin{methoddesc}{set_debuglevel}{debuglevel}
Set the debug level.  The higher the value of \var{debuglevel}, the
more debug output you get (on \code{sys.stdout}).
\end{methoddesc}

\begin{methoddesc}{close}{}
Close the connection.
\end{methoddesc}

\begin{methoddesc}{get_socket}{}
Return the socket object used internally.
\end{methoddesc}

\begin{methoddesc}{fileno}{}
Return the file descriptor of the socket object used internally.
\end{methoddesc}

\begin{methoddesc}{write}{buffer}
Write a string to the socket, doubling any IAC characters.
This can block if the connection is blocked.  May raise
\exception{socket.error} if the connection is closed.
\end{methoddesc}

\begin{methoddesc}{interact}{}
Interaction function, emulates a very dumb telnet client.
\end{methoddesc}

\begin{methoddesc}{mt_interact}{}
Multithreaded version of \method{interact()}.
\end{methoddesc}

\begin{methoddesc}{expect}{list\optional{, timeout}}
Read until one from a list of a regular expressions matches.

The first argument is a list of regular expressions, either
compiled (\class{re.RegexObject} instances) or uncompiled (strings).
The optional second argument is a timeout, in seconds; the default
is to block indefinately.

Return a tuple of three items: the index in the list of the
first regular expression that matches; the match object
returned; and the text read up till and including the match.

If end of file is found and no text was read, raise
\exception{EOFError}.  Otherwise, when nothing matches, return
\code{(-1, None, \var{text})} where \var{text} is the text received so
far (may be the empty string if a timeout happened).

If a regular expression ends with a greedy match (e.g. \regexp{.*})
or if more than one expression can match the same input, the
results are undeterministic, and may depend on the I/O timing.
\end{methoddesc}