NAME¶

Expect::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:

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)