IO::Pipe

Section: Perl Programmers Reference Guide (3pm)
Updated: 2021-03-31
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NAME

IO::Pipe - supply object methods for pipes

SYNOPSIS

        use IO::Pipe;

        $pipe = IO::Pipe->new();

        if($pid = fork()) { # Parent
            $pipe->reader();

            while(<$pipe>) {
                ...
            }

        }
        elsif(defined $pid) { # Child
            $pipe->writer();

            print $pipe ...
        }

        or

        $pipe = IO::Pipe->new();

        $pipe->reader(qw(ls -l));

        while(<$pipe>) {
            ...
        }

DESCRIPTION

"IO::Pipe" provides an interface to creating pipes between processes.

CONSTRUCTOR

new ( [READER, WRITER] ): Creates an "IO::Pipe", which is a reference to a newly created symbol (see the "Symbol" package). "IO::Pipe::new" optionally takes two arguments, which should be objects blessed into "IO::Handle", or a subclass thereof. These two objects will be used for the system call to "pipe". If no arguments are given then method "handles" is called on the new "IO::Pipe" object.
These two handles are held in the array part of the GLOB until either "reader" or "writer" is called.

METHODS

reader ([ARGS]): The object is re-blessed into a sub-class of "IO::Handle", and becomes a handle at the reading end of the pipe. If "ARGS" are given then "fork" is called and "ARGS" are passed to exec.
writer ([ARGS]): The object is re-blessed into a sub-class of "IO::Handle", and becomes a handle at the writing end of the pipe. If "ARGS" are given then "fork" is called and "ARGS" are passed to exec.
handles (): This method is called during construction by "IO::Pipe::new" on the newly created "IO::Pipe" object. It returns an array of two objects blessed into "IO::Pipe::End", or a subclass thereof.

AUTHOR

Graham Barr. Currently maintained by the Perl Porters. Please report all bugs to <perlbug@perl.org>.