POE::Pipe::TwoWay(3pm) - phpMan

POE::Pipe::TwoWay(3pm) User Contributed Perl Documentation POE::Pipe::TwoWay(3pm)

NAME
POE::Pipe::TwoWay - a portable API for two-way pipes

SYNOPSIS
my ($a_read, $a_write, $b_read, $b_write) = POE::Pipe::TwoWay->new();
die "couldn't create a pipe: $!" unless defined $a_read;

DESCRIPTION
Pipes are troublesome beasts because there are a few different, incompatible ways to
create them, and many operating systems implement some subset of them. Therefore it's
impossible to rely on a particular method for their creation.

POE::Pipe::TwoWay will attempt to create a bidirectional pipe using an appropriate method.
If that fails, it will fall back to some other means until success or all methods have
been exhausted. Some operating systems require certain exceptions, which are hardcoded
into the library.

The upshot of all this is that an application can use POE::Pipe::TwoWay to create a
bidirectional pipe without worrying about the mechanism that works in the current runtime
environment.

By the way, POE::Pipe::TwoWay doesn't use POE internally, so it may be used in stand-alone
applications without POE.

PUBLIC METHODS
new [TYPE]

Create a new two-way pipe, optionally constraining it to a particular TYPE of pipe. Two-
way pipes have two ends, both of which can be read from and written to. Therefore, a
successful new() call will return four handles: read and write for one end, and read and
write for the other. On failure, new() sets $! to describe the error and returns nothing.

my ($a_read, $a_write, $b_read, $b_write) = POE::Pipe::TwoWay->new();
die $! unless defined $a_read;

TYPE may be one of "pipe", "socketpair", or "inet". When set, POE::Pipe::TwoWay will
constrain its search to either "pipe()", a UNIX-domain "socketpair()", or plain old
sockets, respectively. Otherwise new() will try each method in order, or a particular
method predetermined to be the best one for the current operating environment.

BUGS
POE::Pipe::OneWay may block up to one second on some systems if failure occurs while
trying to create "inet" sockets.