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<!doctype html PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html><head><title>Python: module pexpect</title>
</head><body bgcolor="#f0f0f8">
<table width="100%" cellspacing=0 cellpadding=2 border=0 summary="heading">
<tr bgcolor="#7799ee">
<td valign=bottom> <br>
<font color="#ffffff" face="helvetica, arial"> <br><big><big><strong>pexpect</strong></big></big> (version 2.1)</font></td
><td align=right valign=bottom
><font color="#ffffff" face="helvetica, arial"><a href=".">index</a><br><a href="file:/home/noah/documents/export/engineering/source/python/pexpect/trunk/pexpect/pexpect.py">/home/noah/documents/export/engineering/source/python/pexpect/trunk/pexpect/pexpect.py</a></font></td></tr></table>
<p><tt>Pexpect is a Python module for spawning child applications and controlling<br>
them automatically. Pexpect can be used for automating interactive applications<br>
such as ssh, ftp, passwd, telnet, etc. It can be used to a automate setup<br>
scripts for duplicating software package installations on different servers. It<br>
can be used for automated software testing. Pexpect is in the spirit of Don<br>
Libes' Expect, but Pexpect is pure Python. Other Expect-like modules for Python<br>
require TCL and Expect or require C extensions to be compiled. Pexpect does not<br>
use C, Expect, or TCL extensions. It should work on any platform that supports<br>
the standard Python pty module. The Pexpect interface focuses on ease of use so<br>
that simple tasks are easy.<br>
<br>
There are two main interfaces to Pexpect -- the function, <a href="#-run">run</a>() and the class,<br>
<a href="#spawn">spawn</a>. You can call the <a href="#-run">run</a>() function to execute a command and return the<br>
output. This is a handy replacement for os.system().<br>
<br>
For example:<br>
pexpect.<a href="#-run">run</a>('ls -la')<br>
<br>
The more powerful interface is the <a href="#spawn">spawn</a> class. You can use this to <a href="#spawn">spawn</a> an<br>
external child command and then interact with the child by sending lines and<br>
expecting responses.<br>
<br>
For example:<br>
child = pexpect.<a href="#spawn">spawn</a>('scp foo myname@host.example.com:.')<br>
child.expect ('Password:')<br>
child.sendline (mypassword)<br>
<br>
This works even for commands that ask for passwords or other input outside of<br>
the normal stdio streams.<br>
<br>
Credits:<br>
Noah Spurrier, Richard Holden, Marco Molteni, Kimberley Burchett, Robert Stone,<br>
Hartmut Goebel, Chad Schroeder, Erick Tryzelaar, Dave Kirby, Ids vander Molen,<br>
George Todd, Noel Taylor, Nicolas D. Cesar, Alexander Gattin,<br>
Geoffrey Marshall, Francisco Lourenco, Glen Mabey, Karthik Gurusamy,<br>
Fernando Perez <br>
(Let me know if I forgot anyone.)<br>
<br>
Free, open source, and all that good stuff.<br>
<br>
Permission is hereby granted, free of charge, to any person obtaining a copy of<br>
this software and associated documentation files (the "Software"), to deal in<br>
the Software without restriction, including without limitation the rights to<br>
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies<br>
of the Software, and to permit persons to whom the Software is furnished to do<br>
so, subject to the following conditions:<br>
<br>
The above copyright notice and this permission notice shall be included in all<br>
copies or substantial portions of the Software.<br>
<br>
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR<br>
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,<br>
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE<br>
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER<br>
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,<br>
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE<br>
SOFTWARE.<br>
<br>
Pexpect Copyright (c) 2006 Noah Spurrier<br>
<a href="http://pexpect.sourceforge.net/">http://pexpect.sourceforge.net/</a><br>
<br>
$Revision: 395 $<br>
$Date: 2006-05-31 20:07:18 -0700 (Wed, 31 May 2006) $</tt></p>
<p>
<table width="100%" cellspacing=0 cellpadding=2 border=0 summary="section">
<tr bgcolor="#aa55cc">
<td colspan=3 valign=bottom> <br>
<font color="#fffff" face="helvetica, arial"><big><strong>Modules</strong></big></font></td></tr>
<tr><td bgcolor="#aa55cc"><tt> </tt></td><td> </td>
<td width="100%"><table width="100%" summary="list"><tr><td width="25%" valign=top><a href="errno.html">errno</a><br>
<a href="fcntl.html">fcntl</a><br>
<a href="os.html">os</a><br>
<a href="pty.html">pty</a><br>
</td><td width="25%" valign=top><a href="re.html">re</a><br>
<a href="resource.html">resource</a><br>
<a href="select.html">select</a><br>
<a href="signal.html">signal</a><br>
</td><td width="25%" valign=top><a href="string.html">string</a><br>
<a href="struct.html">struct</a><br>
<a href="sys.html">sys</a><br>
<a href="termios.html">termios</a><br>
</td><td width="25%" valign=top><a href="time.html">time</a><br>
<a href="traceback.html">traceback</a><br>
<a href="tty.html">tty</a><br>
<a href="types.html">types</a><br>
</td></tr></table></td></tr></table><p>
<table width="100%" cellspacing=0 cellpadding=2 border=0 summary="section">
<tr bgcolor="#ee77aa">
<td colspan=3 valign=bottom> <br>
<font color="#ffffff" face="helvetica, arial"><big><strong>Classes</strong></big></font></td></tr>
<tr><td bgcolor="#ee77aa"><tt> </tt></td><td> </td>
<td width="100%"><dl>
<dt><font face="helvetica, arial"><a href="__builtin__.html#object">__builtin__.object</a>
</font></dt><dd>
<dl>
<dt><font face="helvetica, arial"><a href="pexpect.html#spawn">spawn</a>
</font></dt></dl>
</dd>
<dt><font face="helvetica, arial"><a href="exceptions.html#Exception">exceptions.Exception</a>
</font></dt><dd>
<dl>
<dt><font face="helvetica, arial"><a href="pexpect.html#ExceptionPexpect">ExceptionPexpect</a>
</font></dt><dd>
<dl>
<dt><font face="helvetica, arial"><a href="pexpect.html#EOF">EOF</a>
</font></dt><dt><font face="helvetica, arial"><a href="pexpect.html#TIMEOUT">TIMEOUT</a>
</font></dt></dl>
</dd>
</dl>
</dd>
</dl>
<p>
<table width="100%" cellspacing=0 cellpadding=2 border=0 summary="section">
<tr bgcolor="#ffc8d8">
<td colspan=3 valign=bottom> <br>
<font color="#000000" face="helvetica, arial"><a name="EOF">class <strong>EOF</strong></a>(<a href="pexpect.html#ExceptionPexpect">ExceptionPexpect</a>)</font></td></tr>
<tr bgcolor="#ffc8d8"><td rowspan=2><tt> </tt></td>
<td colspan=2><tt>Raised when <a href="#EOF">EOF</a> is read from a child.<br> </tt></td></tr>
<tr><td> </td>
<td width="100%"><dl><dt>Method resolution order:</dt>
<dd><a href="pexpect.html#EOF">EOF</a></dd>
<dd><a href="pexpect.html#ExceptionPexpect">ExceptionPexpect</a></dd>
<dd><a href="exceptions.html#Exception">exceptions.Exception</a></dd>
</dl>
<hr>
Methods inherited from <a href="pexpect.html#ExceptionPexpect">ExceptionPexpect</a>:<br>
<dl><dt><a name="EOF-__init__"><strong>__init__</strong></a>(self, value)</dt></dl>
<dl><dt><a name="EOF-__str__"><strong>__str__</strong></a>(self)</dt></dl>
<dl><dt><a name="EOF-get_trace"><strong>get_trace</strong></a>(self)</dt><dd><tt>This returns an abbreviated stack trace with lines that only concern the caller.<br>
In other words, the stack trace inside the Pexpect module is not included.</tt></dd></dl>
<hr>
Methods inherited from <a href="exceptions.html#Exception">exceptions.Exception</a>:<br>
<dl><dt><a name="EOF-__getitem__"><strong>__getitem__</strong></a>(...)</dt></dl>
</td></tr></table> <p>
<table width="100%" cellspacing=0 cellpadding=2 border=0 summary="section">
<tr bgcolor="#ffc8d8">
<td colspan=3 valign=bottom> <br>
<font color="#000000" face="helvetica, arial"><a name="ExceptionPexpect">class <strong>ExceptionPexpect</strong></a>(<a href="exceptions.html#Exception">exceptions.Exception</a>)</font></td></tr>
<tr bgcolor="#ffc8d8"><td rowspan=2><tt> </tt></td>
<td colspan=2><tt>Base class for all exceptions raised by this module.<br> </tt></td></tr>
<tr><td> </td>
<td width="100%">Methods defined here:<br>
<dl><dt><a name="ExceptionPexpect-__init__"><strong>__init__</strong></a>(self, value)</dt></dl>
<dl><dt><a name="ExceptionPexpect-__str__"><strong>__str__</strong></a>(self)</dt></dl>
<dl><dt><a name="ExceptionPexpect-get_trace"><strong>get_trace</strong></a>(self)</dt><dd><tt>This returns an abbreviated stack trace with lines that only concern the caller.<br>
In other words, the stack trace inside the Pexpect module is not included.</tt></dd></dl>
<hr>
Methods inherited from <a href="exceptions.html#Exception">exceptions.Exception</a>:<br>
<dl><dt><a name="ExceptionPexpect-__getitem__"><strong>__getitem__</strong></a>(...)</dt></dl>
</td></tr></table> <p>
<table width="100%" cellspacing=0 cellpadding=2 border=0 summary="section">
<tr bgcolor="#ffc8d8">
<td colspan=3 valign=bottom> <br>
<font color="#000000" face="helvetica, arial"><a name="TIMEOUT">class <strong>TIMEOUT</strong></a>(<a href="pexpect.html#ExceptionPexpect">ExceptionPexpect</a>)</font></td></tr>
<tr bgcolor="#ffc8d8"><td rowspan=2><tt> </tt></td>
<td colspan=2><tt>Raised when a read time exceeds the timeout.<br> </tt></td></tr>
<tr><td> </td>
<td width="100%"><dl><dt>Method resolution order:</dt>
<dd><a href="pexpect.html#TIMEOUT">TIMEOUT</a></dd>
<dd><a href="pexpect.html#ExceptionPexpect">ExceptionPexpect</a></dd>
<dd><a href="exceptions.html#Exception">exceptions.Exception</a></dd>
</dl>
<hr>
Methods inherited from <a href="pexpect.html#ExceptionPexpect">ExceptionPexpect</a>:<br>
<dl><dt><a name="TIMEOUT-__init__"><strong>__init__</strong></a>(self, value)</dt></dl>
<dl><dt><a name="TIMEOUT-__str__"><strong>__str__</strong></a>(self)</dt></dl>
<dl><dt><a name="TIMEOUT-get_trace"><strong>get_trace</strong></a>(self)</dt><dd><tt>This returns an abbreviated stack trace with lines that only concern the caller.<br>
In other words, the stack trace inside the Pexpect module is not included.</tt></dd></dl>
<hr>
Methods inherited from <a href="exceptions.html#Exception">exceptions.Exception</a>:<br>
<dl><dt><a name="TIMEOUT-__getitem__"><strong>__getitem__</strong></a>(...)</dt></dl>
</td></tr></table> <p>
<table width="100%" cellspacing=0 cellpadding=2 border=0 summary="section">
<tr bgcolor="#ffc8d8">
<td colspan=3 valign=bottom> <br>
<font color="#000000" face="helvetica, arial"><a name="spawn">class <strong>spawn</strong></a>(<a href="__builtin__.html#object">__builtin__.object</a>)</font></td></tr>
<tr bgcolor="#ffc8d8"><td rowspan=2><tt> </tt></td>
<td colspan=2><tt>This is the main class interface for Pexpect.<br>
Use this class to start and control child applications.<br> </tt></td></tr>
<tr><td> </td>
<td width="100%">Methods defined here:<br>
<dl><dt><a name="spawn-__del__"><strong>__del__</strong></a>(self)</dt><dd><tt>This makes sure that no system resources are left open.<br>
Python only garbage collects Python objects. OS file descriptors<br>
are not Python objects, so they must be handled explicitly.<br>
If the child file descriptor was opened outside of this class<br>
(passed to the constructor) then this does not close it.</tt></dd></dl>
<dl><dt><a name="spawn-__init__"><strong>__init__</strong></a>(self, command, args<font color="#909090">=[]</font>, timeout<font color="#909090">=30</font>, maxread<font color="#909090">=2000</font>, searchwindowsize<font color="#909090">=None</font>, logfile<font color="#909090">=None</font>, env<font color="#909090">=None</font>)</dt><dd><tt>This is the constructor. The command parameter may be a string<br>
that includes a command and any arguments to the command. For example:<br>
p = pexpect.<a href="#spawn">spawn</a> ('/usr/bin/ftp')<br>
p = pexpect.<a href="#spawn">spawn</a> ('/usr/bin/ssh user@example.com')<br>
p = pexpect.<a href="#spawn">spawn</a> ('ls -latr /tmp')<br>
You may also construct it with a list of arguments like so:<br>
p = pexpect.<a href="#spawn">spawn</a> ('/usr/bin/ftp', [])<br>
p = pexpect.<a href="#spawn">spawn</a> ('/usr/bin/ssh', ['user@example.com'])<br>
p = pexpect.<a href="#spawn">spawn</a> ('ls', ['-latr', '/tmp'])<br>
After this the child application will be created and<br>
will be ready to talk to. For normal use, see <a href="#spawn-expect">expect</a>() and <br>
<a href="#spawn-send">send</a>() and <a href="#spawn-sendline">sendline</a>().<br>
<br>
The maxread attribute sets the read buffer size.<br>
This is maximum number of bytes that Pexpect will try to read<br>
from a TTY at one time.<br>
Seeting the maxread size to 1 will turn off buffering.<br>
Setting the maxread value higher may help performance in cases<br>
where large amounts of output are read back from the child.<br>
This feature is useful in conjunction with searchwindowsize.<br>
<br>
The searchwindowsize attribute sets the how far back in<br>
the incomming seach buffer Pexpect will search for pattern matches.<br>
Every time Pexpect reads some data from the child it will append the data to<br>
the incomming buffer. The default is to search from the beginning of the<br>
imcomming buffer each time new data is read from the child.<br>
But this is very inefficient if you are running a command that<br>
generates a large amount of data where you want to match<br>
The searchwindowsize does not effect the size of the incomming data buffer.<br>
You will still have access to the full buffer after <a href="#spawn-expect">expect</a>() returns.<br>
<br>
The logfile member turns on or off logging.<br>
All input and output will be copied to the given file <a href="__builtin__.html#object">object</a>.<br>
Set logfile to None to stop logging. This is the default.<br>
Set logfile to sys.stdout to echo everything to standard output.<br>
The logfile is flushed after each write.<br>
Example 1:<br>
child = pexpect.<a href="#spawn">spawn</a>('some_command')<br>
fout = file('mylog.txt','w')<br>
child.logfile = fout<br>
Example 2:<br>
child = pexpect.<a href="#spawn">spawn</a>('some_command')<br>
child.logfile = sys.stdout<br>
<br>
The delaybeforesend helps overcome a weird behavior that many users were experiencing.<br>
The typical problem was that a user would <a href="#spawn-expect">expect</a>() a "Password:" prompt and<br>
then immediately call <a href="#spawn-sendline">sendline</a>() to send the password. The user would then<br>
see that their password was echoed back to them. Passwords don't<br>
normally echo. The problem is caused by the fact that most applications<br>
print out the "Password" prompt and then turn off stdin echo, but if you<br>
send your password before the application turned off echo, then you get<br>
your password echoed. Normally this wouldn't be a problem when interacting<br>
with a human at a real heyboard. If you introduce a slight delay just before <br>
writing then this seems to clear up the problem. This was such a common problem <br>
for many users that I decided that the default pexpect behavior<br>
should be to sleep just before writing to the child application.<br>
1/10th of a second (100 ms) seems to be enough to clear up the problem.<br>
You can set delaybeforesend to 0 to return to the old behavior.<br>
<br>
Note that <a href="#spawn">spawn</a> is clever about finding commands on your path.<br>
It uses the same logic that "which" uses to find executables.<br>
<br>
If you wish to get the exit status of the child you must call<br>
the <a href="#spawn-close">close</a>() method. The exit or signal status of the child will be<br>
stored in self.<strong>exitstatus</strong> or self.<strong>signalstatus</strong>.<br>
If the child exited normally then exitstatus will store the exit return code and<br>
signalstatus will be None.<br>
If the child was terminated abnormally with a signal then signalstatus will store<br>
the signal value and exitstatus will be None.<br>
If you need more detail you can also read the self.<strong>status</strong> member which stores<br>
the status returned by os.waitpid. You can interpret this using<br>
os.WIFEXITED/os.WEXITSTATUS or os.WIFSIGNALED/os.TERMSIG.</tt></dd></dl>
<dl><dt><a name="spawn-__iter__"><strong>__iter__</strong></a>(self)</dt><dd><tt>This is to support iterators over a file-like <a href="__builtin__.html#object">object</a>.</tt></dd></dl>
<dl><dt><a name="spawn-__str__"><strong>__str__</strong></a>(self)</dt><dd><tt>This returns the current state of the pexpect <a href="__builtin__.html#object">object</a> as a string.</tt></dd></dl>
<dl><dt><a name="spawn-close"><strong>close</strong></a>(self, force<font color="#909090">=True</font>)</dt><dd><tt>This closes the connection with the child application.<br>
Note that calling <a href="#spawn-close">close</a>() more than once is valid.<br>
This emulates standard Python behavior with files.<br>
Set force to True if you want to make sure that the child is terminated<br>
(SIGKILL is sent if the child ignores SIGHUP and SIGINT).</tt></dd></dl>
<dl><dt><a name="spawn-compile_pattern_list"><strong>compile_pattern_list</strong></a>(self, patterns)</dt><dd><tt>This compiles a pattern-string or a list of pattern-strings.<br>
Patterns must be a StringType, <a href="#EOF">EOF</a>, <a href="#TIMEOUT">TIMEOUT</a>, SRE_Pattern, or <br>
a list of those. Patterns may also be None which results in<br>
an empty list.<br>
<br>
This is used by <a href="#spawn-expect">expect</a>() when calling <a href="#spawn-expect_list">expect_list</a>().<br>
Thus <a href="#spawn-expect">expect</a>() is nothing more than::<br>
cpl = <a href="#spawn-compile_pattern_list">compile_pattern_list</a>(pl)<br>
return <a href="#spawn-expect_list">expect_list</a>(clp, timeout)<br>
<br>
If you are using <a href="#spawn-expect">expect</a>() within a loop it may be more<br>
efficient to compile the patterns first and then call <a href="#spawn-expect_list">expect_list</a>().<br>
This avoid calls in a loop to <a href="#spawn-compile_pattern_list">compile_pattern_list</a>():<br>
cpl = <a href="#spawn-compile_pattern_list">compile_pattern_list</a>(my_pattern)<br>
while some_condition:<br>
...<br>
i = <a href="#spawn-expect_list">expect_list</a>(clp, timeout)<br>
...</tt></dd></dl>
<dl><dt><a name="spawn-eof"><strong>eof</strong></a>(self)</dt><dd><tt>This returns True if the <a href="#EOF">EOF</a> exception was ever raised.</tt></dd></dl>
<dl><dt><a name="spawn-expect"><strong>expect</strong></a>(self, pattern, timeout<font color="#909090">=-1</font>, searchwindowsize<font color="#909090">=None</font>)</dt><dd><tt>This seeks through the stream until a pattern is matched.<br>
The pattern is overloaded and may take several types including a list.<br>
The pattern can be a StringType, <a href="#EOF">EOF</a>, a compiled re, or a list of<br>
those types. Strings will be compiled to re types. This returns the<br>
index into the pattern list. If the pattern was not a list this<br>
returns index 0 on a successful match. This may raise exceptions for<br>
<a href="#EOF">EOF</a> or <a href="#TIMEOUT">TIMEOUT</a>. To avoid the <a href="#EOF">EOF</a> or <a href="#TIMEOUT">TIMEOUT</a> exceptions add<br>
<a href="#EOF">EOF</a> or <a href="#TIMEOUT">TIMEOUT</a> to the pattern list.<br>
<br>
After a match is found the instance attributes<br>
'before', 'after' and 'match' will be set.<br>
You can see all the data read before the match in 'before'.<br>
You can see the data that was matched in 'after'.<br>
The re.MatchObject used in the re match will be in 'match'.<br>
If an error occured then 'before' will be set to all the<br>
data read so far and 'after' and 'match' will be None.<br>
<br>
If timeout is -1 then timeout will be set to the self.<strong>timeout</strong> value.<br>
<br>
Note: A list entry may be <a href="#EOF">EOF</a> or <a href="#TIMEOUT">TIMEOUT</a> instead of a string.<br>
This will catch these exceptions and return the index<br>
of the list entry instead of raising the exception.<br>
The attribute 'after' will be set to the exception type.<br>
The attribute 'match' will be None.<br>
This allows you to write code like this:<br>
index = p.expect (['good', 'bad', pexpect.<a href="#EOF">EOF</a>, pexpect.<a href="#TIMEOUT">TIMEOUT</a>])<br>
if index == 0:<br>
do_something()<br>
elif index == 1:<br>
do_something_else()<br>
elif index == 2:<br>
do_some_other_thing()<br>
elif index == 3:<br>
do_something_completely_different()<br>
instead of code like this:<br>
try:<br>
index = p.expect (['good', 'bad'])<br>
if index == 0:<br>
do_something()<br>
elif index == 1:<br>
do_something_else()<br>
except <a href="#EOF">EOF</a>:<br>
do_some_other_thing()<br>
except <a href="#TIMEOUT">TIMEOUT</a>:<br>
do_something_completely_different()<br>
These two forms are equivalent. It all depends on what you want.<br>
You can also just expect the <a href="#EOF">EOF</a> if you are waiting for all output<br>
of a child to finish. For example:<br>
p = pexpect.<a href="#spawn">spawn</a>('/bin/ls')<br>
p.expect (pexpect.<a href="#EOF">EOF</a>)<br>
print p.before<br>
<br>
If you are trying to optimize for speed then see <a href="#spawn-expect_list">expect_list</a>().</tt></dd></dl>
<dl><dt><a name="spawn-expect_exact"><strong>expect_exact</strong></a>(self, pattern_list, timeout<font color="#909090">=-1</font>)</dt><dd><tt>This method is no longer supported or allowed.<br>
It was too hard to maintain and keep it up to date with expect_list.<br>
Few people used this method. Most people favored reliability over speed.<br>
The implementation is left in comments in case anyone needs to hack this<br>
feature back into their copy.<br>
If someone wants to diff this with expect_list and make them work<br>
nearly the same then I will consider adding this make in.</tt></dd></dl>
<dl><dt><a name="spawn-expect_list"><strong>expect_list</strong></a>(self, pattern_list, timeout<font color="#909090">=-1</font>, searchwindowsize<font color="#909090">=-1</font>)</dt><dd><tt>This takes a list of compiled regular expressions and returns <br>
the index into the pattern_list that matched the child output.<br>
The list may also contain <a href="#EOF">EOF</a> or <a href="#TIMEOUT">TIMEOUT</a> (which are not<br>
compiled regular expressions). This method is similar to<br>
the <a href="#spawn-expect">expect</a>() method except that <a href="#spawn-expect_list">expect_list</a>() does not<br>
recompile the pattern list on every call.<br>
This may help if you are trying to optimize for speed, otherwise<br>
just use the <a href="#spawn-expect">expect</a>() method. This is called by <a href="#spawn-expect">expect</a>().<br>
If timeout==-1 then the self.<strong>timeout</strong> value is used.<br>
If searchwindowsize==-1 then the self.<strong>searchwindowsize</strong> value is used.</tt></dd></dl>
<dl><dt><a name="spawn-fileno"><strong>fileno</strong></a>(self)</dt><dd><tt>This returns the file descriptor of the pty for the child.</tt></dd></dl>
<dl><dt><a name="spawn-flush"><strong>flush</strong></a>(self)</dt><dd><tt>This does nothing. It is here to support the interface for a File-like <a href="__builtin__.html#object">object</a>.</tt></dd></dl>
<dl><dt><a name="spawn-getwinsize"><strong>getwinsize</strong></a>(self)</dt><dd><tt>This returns the terminal window size of the child tty.<br>
The return value is a tuple of (rows, cols).</tt></dd></dl>
<dl><dt><a name="spawn-interact"><strong>interact</strong></a>(self, escape_character<font color="#909090">='<font color="#c040c0">\x1d</font>'</font>, input_filter<font color="#909090">=None</font>, output_filter<font color="#909090">=None</font>)</dt><dd><tt>This gives control of the child process to the interactive user<br>
(the human at the keyboard).<br>
Keystrokes are sent to the child process, and the stdout and stderr<br>
output of the child process is printed.<br>
This simply echos the child stdout and child stderr to the real<br>
stdout and it echos the real stdin to the child stdin.<br>
When the user types the escape_character this method will stop.<br>
The default for escape_character is ^]. This should not be confused<br>
with ASCII 27 -- the ESC character. ASCII 29 was chosen<br>
for historical merit because this is the character used<br>
by 'telnet' as the escape character. The escape_character will<br>
not be sent to the child process.<br>
<br>
You may pass in optional input and output filter functions.<br>
These functions should take a string and return a string.<br>
The output_filter will be passed all the output from the child process.<br>
The input_filter will be passed all the keyboard input from the user.<br>
The input_filter is run BEFORE the check for the escape_character.<br>
<br>
Note that if you change the window size of the parent<br>
the SIGWINCH signal will not be passed through to the child.<br>
If you want the child window size to change when the parent's<br>
window size changes then do something like the following example:<br>
import pexpect, struct, fcntl, termios, signal, sys<br>
def sigwinch_passthrough (sig, data):<br>
s = struct.pack("HHHH", 0, 0, 0, 0)<br>
a = struct.unpack('hhhh', fcntl.ioctl(sys.stdout.<a href="#spawn-fileno">fileno</a>(), termios.TIOCGWINSZ , s))<br>
global p<br>
p.<a href="#spawn-setwinsize">setwinsize</a>(a[0],a[1])<br>
p = pexpect.<a href="#spawn">spawn</a>('/bin/bash') # Note this is global and used in sigwinch_passthrough.<br>
signal.signal(signal.SIGWINCH, sigwinch_passthrough)<br>
p.<a href="#spawn-interact">interact</a>()</tt></dd></dl>
<dl><dt><a name="spawn-isalive"><strong>isalive</strong></a>(self)</dt><dd><tt>This tests if the child process is running or not.<br>
This is non-blocking. If the child was terminated then this<br>
will read the exitstatus or signalstatus of the child.<br>
This returns True if the child process appears to be running or False if not.<br>
It can take literally SECONDS for Solaris to return the right status.</tt></dd></dl>
<dl><dt><a name="spawn-isatty"><strong>isatty</strong></a>(self)</dt><dd><tt>This returns True if the file descriptor is open and connected to a tty(-like) device, else False.</tt></dd></dl>
<dl><dt><a name="spawn-kill"><strong>kill</strong></a>(self, sig)</dt><dd><tt>This sends the given signal to the child application.<br>
In keeping with UNIX tradition it has a misleading name.<br>
It does not necessarily kill the child unless<br>
you send the right signal.</tt></dd></dl>
<dl><dt><a name="spawn-next"><strong>next</strong></a>(self)</dt><dd><tt>This is to support iterators over a file-like <a href="__builtin__.html#object">object</a>.</tt></dd></dl>
<dl><dt><a name="spawn-read"><strong>read</strong></a>(self, size<font color="#909090">=-1</font>)</dt><dd><tt>This reads at most "size" bytes from the file <br>
(less if the read hits <a href="#EOF">EOF</a> before obtaining size bytes). <br>
If the size argument is negative or omitted, <br>
read all data until <a href="#EOF">EOF</a> is reached. <br>
The bytes are returned as a string <a href="__builtin__.html#object">object</a>. <br>
An empty string is returned when <a href="#EOF">EOF</a> is encountered immediately.</tt></dd></dl>
<dl><dt><a name="spawn-read_nonblocking"><strong>read_nonblocking</strong></a>(self, size<font color="#909090">=1</font>, timeout<font color="#909090">=-1</font>)</dt><dd><tt>This reads at most size characters from the child application.<br>
It includes a timeout. If the read does not complete within the<br>
timeout period then a <a href="#TIMEOUT">TIMEOUT</a> exception is raised.<br>
If the end of file is read then an <a href="#EOF">EOF</a> exception will be raised.<br>
If a log file was set using <a href="#spawn-setlog">setlog</a>() then all data will<br>
also be written to the log file.<br>
<br>
If timeout==None then the read may block indefinitely.<br>
If timeout==-1 then the self.<strong>timeout</strong> value is used.<br>
If timeout==0 then the child is polled and <br>
if there was no data immediately ready then this will raise a <a href="#TIMEOUT">TIMEOUT</a> exception.<br>
<br>
The "timeout" refers only to the amount of time to read at least one character.<br>
This is not effected by the 'size' parameter, so if you call<br>
<a href="#spawn-read_nonblocking">read_nonblocking</a>(size=100, timeout=30) and only one character is<br>
available right away then one character will be returned immediately. <br>
It will not wait for 30 seconds for another 99 characters to come in.<br>
<br>
This is a wrapper around os.<a href="#spawn-read">read</a>().<br>
It uses select.select() to implement a timeout.</tt></dd></dl>
<dl><dt><a name="spawn-readline"><strong>readline</strong></a>(self, size<font color="#909090">=-1</font>)</dt><dd><tt>This reads and returns one entire line. A trailing newline is kept in<br>
the string, but may be absent when a file ends with an incomplete line. <br>
Note: This <a href="#spawn-readline">readline</a>() looks for a \r\n pair even on UNIX because<br>
this is what the pseudo tty device returns. So contrary to what you<br>
may expect you will receive the newline as \r\n.<br>
An empty string is returned when <a href="#EOF">EOF</a> is hit immediately.<br>
Currently, the size agument is mostly ignored, so this behavior is not<br>
standard for a file-like <a href="__builtin__.html#object">object</a>. If size is 0 then an empty string<br>
is returned.</tt></dd></dl>
<dl><dt><a name="spawn-readlines"><strong>readlines</strong></a>(self, sizehint<font color="#909090">=-1</font>)</dt><dd><tt>This reads until <a href="#EOF">EOF</a> using <a href="#spawn-readline">readline</a>() and returns a list containing <br>
the lines thus read. The optional "sizehint" argument is ignored.</tt></dd></dl>
<dl><dt><a name="spawn-send"><strong>send</strong></a>(self, str)</dt><dd><tt>This sends a string to the child process.<br>
This returns the number of bytes written.<br>
If a log file was set then the data is also written to the log.</tt></dd></dl>
<dl><dt><a name="spawn-sendeof"><strong>sendeof</strong></a>(self)</dt><dd><tt>This sends an <a href="#EOF">EOF</a> to the child.<br>
This sends a character which causes the pending parent output<br>
buffer to be sent to the waiting child program without<br>
waiting for end-of-line. If it is the first character of the<br>
line, the <a href="#spawn-read">read</a>() in the user program returns 0, which<br>
signifies end-of-file. This means to work as expected <br>
a <a href="#spawn-sendeof">sendeof</a>() has to be called at the begining of a line. <br>
This method does not send a newline. It is the responsibility<br>
of the caller to ensure the eof is sent at the beginning of a line.</tt></dd></dl>
<dl><dt><a name="spawn-sendline"><strong>sendline</strong></a>(self, str<font color="#909090">=''</font>)</dt><dd><tt>This is like <a href="#spawn-send">send</a>(), but it adds a line feed (os.linesep).<br>
This returns the number of bytes written.</tt></dd></dl>
<dl><dt><a name="spawn-setecho"><strong>setecho</strong></a>(self, state)</dt><dd><tt>This sets the terminal echo mode on or off.<br>
Note that anything the child sent before the echo will be lost, so<br>
you should be sure that your input buffer is empty before you setecho.<br>
For example, the following will work as expected.<br>
p = pexpect.<a href="#spawn">spawn</a>('cat')<br>
p.sendline ('1234') # We will see this twice (once from tty echo and again from cat).<br>
p.expect (['1234'])<br>
p.expect (['1234'])<br>
p.<a href="#spawn-setecho">setecho</a>(False) # Turn off tty echo<br>
p.sendline ('abcd') # We will set this only once (echoed by cat).<br>
p.sendline ('wxyz') # We will set this only once (echoed by cat)<br>
p.expect (['abcd'])<br>
p.expect (['wxyz'])<br>
The following WILL NOT WORK because the lines sent before the setecho<br>
will be lost:<br>
p = pexpect.<a href="#spawn">spawn</a>('cat')<br>
p.sendline ('1234') # We will see this twice (once from tty echo and again from cat).<br>
p.<a href="#spawn-setecho">setecho</a>(False) # Turn off tty echo<br>
p.sendline ('abcd') # We will set this only once (echoed by cat).<br>
p.sendline ('wxyz') # We will set this only once (echoed by cat)<br>
p.expect (['1234'])<br>
p.expect (['1234'])<br>
p.expect (['abcd'])<br>
p.expect (['wxyz'])</tt></dd></dl>
<dl><dt><a name="spawn-setlog"><strong>setlog</strong></a>(self, fileobject)</dt><dd><tt>This method is no longer supported or allowed.</tt></dd></dl>
<dl><dt><a name="spawn-setmaxread"><strong>setmaxread</strong></a>(self, maxread)</dt><dd><tt>This method is no longer supported or allowed.<br>
I don't like getters and setters without a good reason.</tt></dd></dl>
<dl><dt><a name="spawn-setwinsize"><strong>setwinsize</strong></a>(self, r, c)</dt><dd><tt>This sets the terminal window size of the child tty.<br>
This will cause a SIGWINCH signal to be sent to the child.<br>
This does not change the physical window size.<br>
It changes the size reported to TTY-aware applications like<br>
vi or curses -- applications that respond to the SIGWINCH signal.</tt></dd></dl>
<dl><dt><a name="spawn-terminate"><strong>terminate</strong></a>(self, force<font color="#909090">=False</font>)</dt><dd><tt>This forces a child process to terminate.<br>
It starts nicely with SIGHUP and SIGINT. If "force" is True then<br>
moves onto SIGKILL.<br>
This returns True if the child was terminated.<br>
This returns False if the child could not be terminated.</tt></dd></dl>
<dl><dt><a name="spawn-wait"><strong>wait</strong></a>(self)</dt><dd><tt>This waits until the child exits. This is a blocking call.<br>
This will not read any data from the child, so this will block forever<br>
if the child has unread output and has terminated. In other words, the child<br>
may have printed output then called exit(); but, technically, the child is<br>
still alive until its output is read.</tt></dd></dl>
<dl><dt><a name="spawn-write"><strong>write</strong></a>(self, str)</dt><dd><tt>This is similar to <a href="#spawn-send">send</a>() except that there is no return value.</tt></dd></dl>
<dl><dt><a name="spawn-writelines"><strong>writelines</strong></a>(self, sequence)</dt><dd><tt>This calls <a href="#spawn-write">write</a>() for each element in the sequence.<br>
The sequence can be any iterable <a href="__builtin__.html#object">object</a> producing strings, <br>
typically a list of strings. This does not add line separators<br>
There is no return value.</tt></dd></dl>
<hr>
Data and other attributes defined here:<br>
<dl><dt><strong>__dict__</strong> = <dictproxy object><dd><tt>dictionary for instance variables (if defined)</tt></dl>
<dl><dt><strong>__weakref__</strong> = <attribute '__weakref__' of 'spawn' objects><dd><tt>list of weak references to the <a href="__builtin__.html#object">object</a> (if defined)</tt></dl>
</td></tr></table></td></tr></table><p>
<table width="100%" cellspacing=0 cellpadding=2 border=0 summary="section">
<tr bgcolor="#eeaa77">
<td colspan=3 valign=bottom> <br>
<font color="#ffffff" face="helvetica, arial"><big><strong>Functions</strong></big></font></td></tr>
<tr><td bgcolor="#eeaa77"><tt> </tt></td><td> </td>
<td width="100%"><dl><dt><a name="-run"><strong>run</strong></a>(command, timeout<font color="#909090">=-1</font>, withexitstatus<font color="#909090">=False</font>, events<font color="#909090">=None</font>, extra_args<font color="#909090">=None</font>, logfile<font color="#909090">=None</font>)</dt><dd><tt>This function runs the given command; waits for it to finish;<br>
then returns all output as a string. STDERR is included in output.<br>
If the full path to the command is not given then the path is searched.<br>
<br>
Note that lines are terminated by CR/LF (\r\n) combination<br>
even on UNIX-like systems because this is the standard for pseudo ttys.<br>
If you set withexitstatus to true, then run will return a tuple of<br>
(command_output, exitstatus). If withexitstatus is false then this<br>
returns just command_output.<br>
<br>
The <a href="#-run">run</a>() function can often be used instead of creating a <a href="#spawn">spawn</a> instance.<br>
For example, the following code uses <a href="#spawn">spawn</a>:<br>
from pexpect import *<br>
child = <a href="#spawn">spawn</a>('scp foo myname@host.example.com:.')<br>
child.expect ('(?i)password')<br>
child.sendline (mypassword)<br>
The previous code can be replace with the following, which you may<br>
or may not find simpler:<br>
from pexpect import *<br>
run ('scp foo myname@host.example.com:.', events={'(?i)password': mypassword})<br>
<br>
Examples:<br>
Start the apache daemon on the local machine:<br>
from pexpect import *<br>
run ("/usr/local/apache/bin/apachectl start")<br>
Check in a file using SVN:<br>
from pexpect import *<br>
run ("svn ci -m 'automatic commit' my_file.py")<br>
Run a command and capture exit status:<br>
from pexpect import *<br>
(command_output, exitstatus) = run ('ls -l /bin', withexitstatus=1)<br>
<br>
Tricky Examples: <br>
The following will run SSH and execute 'ls -l' on the remote machine.<br>
The password 'secret' will be sent if the '(?i)password' pattern is ever seen.<br>
run ("ssh username@machine.example.com 'ls -l'", events={'(?i)password':'secret<br>
'})<br>
<br>
This will start mencoder to rip a video from DVD. This will also display<br>
progress ticks every 5 seconds as it runs.<br>
from pexpect import *<br>
def print_ticks(d):<br>
print d['event_count'],<br>
run ("mencoder dvd://1 -o video.avi -oac copy -ovc copy", events={<a href="#TIMEOUT">TIMEOUT</a>:print_ticks}, timeout=5)<br>
<br>
The 'events' argument should be a dictionary of patterns and responses.<br>
Whenever one of the patterns is seen in the command out<br>
<a href="#-run">run</a>() will send the associated response string. Note that you should<br>
put newlines in your string if Enter is necessary.<br>
The responses may also contain callback functions.<br>
Any callback is function that takes a dictionary as an argument.<br>
The dictionary contains all the locals from the <a href="#-run">run</a>() function, so<br>
you can access the child <a href="#spawn">spawn</a> <a href="__builtin__.html#object">object</a> or any other variable defined<br>
in <a href="#-run">run</a>() (event_count, child, and extra_args are the most useful).<br>
A callback may return True to stop the current run process otherwise<br>
<a href="#-run">run</a>() continues until the next event.<br>
A callback may also return a string which will be sent to the child.<br>
'extra_args' is not used by directly <a href="#-run">run</a>(). It provides a way to pass data to<br>
a callback function through <a href="#-run">run</a>() through the locals dictionary passed to a callback.</tt></dd></dl>
<dl><dt><a name="-split_command_line"><strong>split_command_line</strong></a>(command_line)</dt><dd><tt>This splits a command line into a list of arguments.<br>
It splits arguments on spaces, but handles<br>
embedded quotes, doublequotes, and escaped characters.<br>
It's impossible to do this with a regular expression, so<br>
I wrote a little state machine to parse the command line.</tt></dd></dl>
<dl><dt><a name="-which"><strong>which</strong></a>(filename)</dt><dd><tt>This takes a given filename; tries to find it in the environment path; <br>
then checks if it is executable.<br>
This returns the full path to the filename if found and executable.<br>
Otherwise this returns None.</tt></dd></dl>
</td></tr></table><p>
<table width="100%" cellspacing=0 cellpadding=2 border=0 summary="section">
<tr bgcolor="#55aa55">
<td colspan=3 valign=bottom> <br>
<font color="#ffffff" face="helvetica, arial"><big><strong>Data</strong></big></font></td></tr>
<tr><td bgcolor="#55aa55"><tt> </tt></td><td> </td>
<td width="100%"><strong>__all__</strong> = ['ExceptionPexpect', 'EOF', 'TIMEOUT', 'spawn', 'run', 'which', 'split_command_line', '__version__', '__revision__']<br>
<strong>__revision__</strong> = '$Revision: 395 $'<br>
<strong>__version__</strong> = '2.1'</td></tr></table>
</body></html>
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