IO(3) User Contributed Perl Documentation IO(3)NAME
Tk::IO - high level interface to Tk's 'fileevent' mechanism
SYNOPSIS
my $fh = Tk::IO->new(-linecommand => callback, -childcommand => callback);
$fh->exec("command")
$fh->wait
$fh->kill
WARNING
INTERFACES TO THIS MODULE MAY CHANGE AS PERL'S IO EVOLVES AND WITH PORT OF TK4.1
DESCRIPTION
Tk::IO is now layered on perl's IO::Handle class. Interfaces have changed, and are still evolving.
In theory C methods which enable non-blocking IO as in earlier Tk-b* release(s) are still there. I have not changed them to use perl's
additional Configure information, or tested them much.
Assumption is that exec is used to fork a child process and a callback is called each time a complete line arrives up the implied pipe.
"line" should probably be defined in terms of perl's input record separator but is not yet.
The -childcommand callback is called when end-of-file occurs.
$fh->wait can be used to wait for child process while processing other Tk events.
$fh->kill can be used to send signal to child process.
BUGS
Still not finished. Idea is to use "exec" to emulate "system" in a non-blocking manner.
perl v5.16.3 2014-06-10 IO(3)
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Child(3pm) User Contributed Perl Documentation Child(3pm)NAME
Child - Object oriented simple interface to fork()
DESCRIPTION
Fork is too low level, and difficult to manage. Often people forget to exit at the end, reap their children, and check exit status. The
problem is the low level functions provided to do these things. Throw in pipes for IPC and you just have a pile of things nobody wants to
think about.
Child is an Object Oriented interface to fork. It provides a clean way to start a child process, and manage it afterwords. It provides
methods for running, waiting, killing, checking, and even communicating with a child process.
NOTE: kill() is unpredictable on windows, strawberry perl sends the kill signal to the parent as well as the child.
SYNOPSIS
BASIC
use Child;
my $child = Child->new(sub {
my ( $parent ) = @_;
....
# exit() is called for you at the end.
});
my $proc = $child->start
# Kill the child if it is not done
$proc->complete || $proc->kill(9);
$proc->wait; #blocking
IPC
# Build with IPC
my $child2 = Child->new(sub {
my $self = shift;
$self->say("message1");
$self->say("message2");
my $reply = $self->read(1);
}, pipe => 1 );
my $proc2 = $child2->start;
# Read (blocking)
my $message1 = $proc2->read();
my $message2 = $proc2->read();
$proc2->say("reply");
SHORTCUT
Child can export the child() shortcut function when requested. This function creates and starts the child process in one action.
use Child qw/child/;
my $proc = child {
my $parent = shift;
...
};
You can also request IPC:
use Child qw/child/;
my $child = child {
my $parent = shift;
...
} pipe => 1;
DETAILS
First you define a child, you do this by constructing a Child object. Defining a child does not start a new process, it is just the way to
define what the new process will look like. Once you have defined the child you can start the process by calling $child->start(). One child
object can start as many processes as you like.
When you start a child an Child::Link::Proc object is returned. This object provides multiple useful methods for interacting with your
process. Within the process itself an Child::Link::Parent is created and passed as the only parameter to the function used to define the
child. The parent object is how the child interacts with its parent.
PROCESS MANAGEMENT METHODS
@procs = Child->all_procs()
Get a list of all the processes that have been started. This list is cleared in processes when they are started; that is a child will
not list its siblings.
@pids = Child->all_proc_pids()
Get a list of all the pids of processes that have been started.
Child->wait_all()
Call wait() on all processes.
EXPORTS
$proc = child( sub { ... } )
$proc = child { ... }
$proc = child( sub { ... }, $plugin, @data )
$proc = child { ... } $plugin => @data
Create and start a process in one action.
CONSTRUCTOR
$child = Child->new( sub { ... } )
$child = Child->new( sub { ... }, $plugin, @plugin_data )
Create a new Child object. Does not start the child.
OBJECT METHODS
$proc = $child->start()
Start the child process.
SEE ALSO
Child::Link::Proc
The proc object that is returned by $child->start()
Child::Link::Parent
The parent object that is provided as the argumunt to the function used to define the child.
Child::Link::IPC
The base class for IPC plugin link objects. This provides the IPC methods.
HISTORY
Most of this was part of Parrallel::Runner intended for use in the Fennec project. Fennec is being broken into multiple parts, this is one
such part.
FENNEC PROJECT
This module is part of the Fennec project. See Fennec for more details. Fennec is a project to develop an extendable and powerful testing
framework. Together the tools that make up the Fennec framework provide a potent testing environment.
The tools provided by Fennec are also useful on their own. Sometimes a tool created for Fennec is useful outside the greator framework.
Such tools are turned into their own projects. This is one such project.
Fennec - The core framework
The primary Fennec project that ties them all together.
AUTHORS
Chad Granum exodist7@gmail.com
COPYRIGHT
Copyright (C) 2010 Chad Granum
Child is free software; Standard perl licence.
Child is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the license for more details.
perl v5.10.1 2011-03-07 Child(3pm)