NAME

IO::React - Interaction with an io handle

SYNOPSIS

  use IO::React;

  my $r = new IO::React($fh);

  $r->set_wait(30);	# Seconds
  $r->set_timeout(sub { ... });
  $r->set_eof(sub { ... });
  $r->set_display(1);	# Boolean

  $r->write("...", ...);

  $r->react('WAIT'     => sub { ... },
	    'TIMEOUT'  => sub { ... },
	    'EOF'      => sub { ... },
	    'pattern1' => sub { ... },
	    'pattern2' => sub { ... },
	    ...);

DESCRIPTION

IO::React provides an expect-like interface for interacting with whatever may be connected to a handle. The main routine is the react method, which calls subroutines based on matching patterns provided as arguments.

There are four methods for controlling the default behaviour of an IO::React object.

The set_wait method controls the default waiting period for react to read data that matches one of the patterns it is looking for.

The set_timeout method sets a subroutine to be called when the waiting period for react expires. If the timeout subroutine returns a defined value, that value will be used as a new waiting period.

The set_eof method sets a subroutine to be called when react reaches the end of file on the handle it is reading from.

The set_display method controls whether or not react prints the data it reads to the default output handle.

Because IO::React uses the select perl function, it is not safe to use buffered io routines on the handle it is processing. For convienience, IO::React provides the <write> method to call syswrite appropriately on the handle.

EXAMPLES

Getting a directory listing via telnet

This is a sample program that would login to a system using telnet and run ls.

use IO::React;
use Proc::Spawn;

my $Prompt   = '\\$';
my $Account  = 'XXX';
my $Password = 'XXX';

my ($pid, $fh) = spawn_pty("telnet localhost");

my $react = new React($fh);
$react->set_display(1);
$react->set_wait(10);

# React to login prompt
$react->react({
  WAIT      => 30,
  'ogin:'   => sub { $react->write("$Account\n") },
  'refused' => sub { print "Server not responding\n"; exit 1 }
}) || die "React Failed";

# React to password prompt
$react->react({
  'word:'  => sub { $react->write("$Password\n") }
}) || die "React Failed";

# React to failure or shell prompt
$react->react({
  'incorrect' => sub { print "\nWrong Account/Password\n"; exit 1 },
  $Prompt     => sub { $react->write("ls\n") },
});

# React to shell prompt
$react->react({
  WAIT    => 60,
  $Prompt => sub { $react->write("exit\n"); exit },
});

AUTHOR

John Redford, John.Redford@fmr.com

SEE ALSO

IO::Handle, Proc::Spawn