Expect::Simple(3) User Contributed Perl Documentation Expect::Simple(3)NAMEExpect::Simple - wrapper around the Expect module
SYNOPSIS
use Expect::Simple;
my $obj = new Expect::Simple
{ Cmd => [ dmcoords => 'verbose=1', "infile=$infile"],
Prompt => [ -re => 'dmcoords>:\s+' ],
DisconnectCmd => 'q',
Verbose => 0,
Debug => 0,
Timeout => 100
};
$obj->send( $cmd );
print $obj->before;
print $obj->after;
print $obj->match_str, "\n";
print $obj->match_idx, "\n";
print $obj->error_expect;
print $obj->error;
$expect_object = $obj->expect_handle;
DESCRIPTION
"Expect::Simple" is a wrapper around the "Expect" module which should
suffice for simple applications. It hides most of the "Expect"
machinery; the "Expect" object is available for tweaking if need be.
Generally, one starts by creating an Expect::Simple object using new.
This will start up the target program, and will wait until one of the
specified prompts is output by the target. At that point the caller
should send() commands to the program; the results are available via
the before, after, match_str, and match_idx methods. Since Expect
simulates a terminal, there will be extra "\r" characters at the end of
each line in the result (on UNIX at least). This is easily fixed:
($res = $obj->before) =~ tr/\r//d;
@lines = split( "\n", $res );
This is not done automatically.
Exceptions will be thrown on error (match with "/Expect::Simple/").
Errors from Expect are available via the error_expect method. More
human readable errors are available via the error method.
The connection is automatically broken (by sending the specified
disconnect command to the target) when the Expect::Simple object is
destroyed.
Methods
new
$obj = Expect::Simple->new( \%attr );
This creates a new object, starting up the program with which
to communicate (using the Expect spawn method) and waiting for
a prompt. The passed hash reference must contain at least the
Prompt, DisconnectCmd, and Cmd elements. The available
attributes are:
Cmd
Cmd => $command,
Cmd => [ $command, $arg1, $arg2, ... ],
The command to which to connect. The passed command
may either be a scalar or an array.
Prompt This specifies one or more prompts to scan for. For a
single prompt, the value may be a scalar; for more, or
for matching of regular expressions, it should be an
array reference. For example,
Prompt => 'prompt1> ',
Prompt => [ 'prompt1> ', 'prompt2> ', -re => 'prompt\d+>\s+' ]
All prompts are taken literally, unless immediately
preceded by a "-re" flag, in which case they are
regular expressions.
DisconnectCmd
This is the command to be sent to the target program
which will cause it to exit.
RawPty If set, then underlying Expect object's pty mode is set
to raw mode (see Expect::raw_pty()).
Timeout The time in seconds to wait until giving up on the
target program responding. This is used during program
startup and when any commands are sent to the program.
It defaults to 1000 seconds.
Debug The value is passed to Expect via its debug method.
Verbose This results in various messages printed to the STDERR
stream. If greater than 3, it turns on Expect's
logging to STDOUT (via the log_stdout Expect method.
send
$obj->send( $cmd );
$obj->send( @cmds );
Send one or more commands to the target. After each command is
sent, it waits for a prompt from the target. Only the output
resulting from the last command is available via the after,
before, etc. methods.
match_idx
This returns a unary based index indicating which prompt (in
the list of prompts specified via the "Prompt" attribute to the
new method) was received after the last command was sent. It
will be undef if none was returned.
match_str
This returns the prompt which was matched after the last
command was sent.
before This returns the string received before the prompt. If no
prompt was seen, it returns all output accumulated. This is
usually what the caller wants to parse. Note that the first
line will (usually) be the command that was sent to the target,
because of echoing. Check this out to be sure!
after This returns the 'after' string. Please read the Expect docs
for more enlightenment.
error This returns a cleaned up, more humanly readable version of the
errors from Expect. It'll be undef if there was no error.
error_expect
This returns the original Expect error.
expect_handle
This returns the Expect object, in case further tweaking is
necessary.
BUGS
If the command to be run does not exist (or not in the current
execution path), it's quite possible that the new method will not throw
an exception. It's up to the caller to make sure that the command will
run! There's no known workaround for this.
LICENSE
This software is released under the GNU General Public License. You
may find a copy at
http://www.fsf.org/copyleft/gpl.html
AUTHOR
Diab Jerius (djerius@cpan.org)
perl v5.14.1 2008-05-06 Expect::Simple(3)
