FM / IO

/usr/lib/x86_64-linux-gnu/perl/5.34.0/IO/

/usr/lib/x86_64-linux-gnu/perl/5.34.0/IO

Name	Size	Mode	Actions
Socket/	-	0755	rm
Dir.pm	5326	0644	edit dl rm
File.pm	4872	0644	edit dl rm
Handle.pm	16641	0644	edit dl rm
Pipe.pm	5461	0644	edit dl rm
Poll.pm	4508	0644	edit dl rm
Seekable.pm	2891	0644	edit dl rm
Select.pm	9263	0644	edit dl rm
Socket.pm	28361	0644	edit dl rm

Edit: /usr/lib/x86_64-linux-gnu/perl/5.34.0/IO/Pipe.pm (5461B)

# IO::Pipe.pm
#
# Copyright (c) 1996-8 Graham Barr <gbarr@pobox.com>. All rights reserved.
# This program is free software; you can redistribute it and/or
# modify it under the same terms as Perl itself.

package IO::Pipe;

use 5.008_001;

use IO::Handle;
use strict;
use Carp;
use Symbol;

our $VERSION = "1.46";

sub new {
    my $type = shift;
    my $class = ref($type) || $type || "IO::Pipe";
    @_ == 0 || @_ == 2 or croak "usage: $class->([READFH, WRITEFH])";

my $me = bless gensym(), $class;

my($readfh,$writefh) = @_ ? @_ : $me->handles;

pipe($readfh, $writefh)
	or return undef;

@{*$me} = ($readfh, $writefh);

$me;
}

sub handles {
    @_ == 1 or croak 'usage: $pipe->handles()';
    (IO::Pipe::End->new(), IO::Pipe::End->new());
}

my $do_spawn = $^O eq 'os2' || $^O eq 'MSWin32';

sub _doit {
    my $me = shift;
    my $rw = shift;

my $pid = $do_spawn ? 0 : fork();

if($pid) { # Parent
        return $pid;
    }
    elsif(defined $pid) { # Child or spawn
        my $fh;
        my $io = $rw ? \*STDIN : \*STDOUT;
        my ($mode, $save) = $rw ? "r" : "w";
        if ($do_spawn) {
          require Fcntl;
          $save = IO::Handle->new_from_fd($io, $mode);
	  my $handle = shift;
          # Close in child:
	  unless ($^O eq 'MSWin32') {
            fcntl($handle, Fcntl::F_SETFD(), 1) or croak "fcntl: $!";
	  }
          $fh = $rw ? ${*$me}[0] : ${*$me}[1];
        } else {
          shift;
          $fh = $rw ? $me->reader() : $me->writer(); # close the other end
        }
        bless $io, "IO::Handle";
        $io->fdopen($fh, $mode);
	$fh->close;

if ($do_spawn) {
          $pid = eval { system 1, @_ }; # 1 == P_NOWAIT
          my $err = $!;
    
          $io->fdopen($save, $mode);
          $save->close or croak "Cannot close $!";
          croak "IO::Pipe: Cannot spawn-NOWAIT: $err" if not $pid or $pid < 0;
          return $pid;
        } else {
          exec @_ or
            croak "IO::Pipe: Cannot exec: $!";
        }
    }
    else {
        croak "IO::Pipe: Cannot fork: $!";
    }

# NOT Reached
}

sub reader {
    @_ >= 1 or croak 'usage: $pipe->reader( [SUB_COMMAND_ARGS] )';
    my $me = shift;

return undef
	unless(ref($me) || ref($me = $me->new));

my $fh  = ${*$me}[0];
    my $pid;
    $pid = $me->_doit(0, $fh, @_)
        if(@_);

close ${*$me}[1];
    bless $me, ref($fh);
    *$me = *$fh;          # Alias self to handle
    $me->fdopen($fh->fileno,"r")
	unless defined($me->fileno);
    bless $fh;                  # Really wan't un-bless here
    ${*$me}{'io_pipe_pid'} = $pid
        if defined $pid;

$me;
}

sub writer {
    @_ >= 1 or croak 'usage: $pipe->writer( [SUB_COMMAND_ARGS] )';
    my $me = shift;

return undef
	unless(ref($me) || ref($me = $me->new));

my $fh  = ${*$me}[1];
    my $pid;
    $pid = $me->_doit(1, $fh, @_)
        if(@_);

close ${*$me}[0];
    bless $me, ref($fh);
    *$me = *$fh;          # Alias self to handle
    $me->fdopen($fh->fileno,"w")
	unless defined($me->fileno);
    bless $fh;                  # Really wan't un-bless here
    ${*$me}{'io_pipe_pid'} = $pid
        if defined $pid;

$me;
}

package IO::Pipe::End;

our(@ISA);

@ISA = qw(IO::Handle);

sub close {
    my $fh = shift;
    my $r = $fh->SUPER::close(@_);

waitpid(${*$fh}{'io_pipe_pid'},0)
	if(defined ${*$fh}{'io_pipe_pid'});

$r;
}

__END__

=head1 NAME

IO::Pipe - supply object methods for pipes

=head1 SYNOPSIS

use IO::Pipe;

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

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

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

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

print $pipe ...
	}

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

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

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

=head1 DESCRIPTION

C<IO::Pipe> provides an interface to creating pipes between
processes.

=head1 CONSTRUCTOR

=over 4

=item new ( [READER, WRITER] )

Creates an C<IO::Pipe>, which is a reference to a newly created symbol
(see the C<Symbol> package). C<IO::Pipe::new> optionally takes two
arguments, which should be objects blessed into C<IO::Handle>, or a
subclass thereof. These two objects will be used for the system call
to C<pipe>. If no arguments are given then method C<handles> is called
on the new C<IO::Pipe> object.

These two handles are held in the array part of the GLOB until either
C<reader> or C<writer> is called.

=back

=head1 METHODS

=over 4

=item reader ([ARGS])

The object is re-blessed into a sub-class of C<IO::Handle>, and becomes a
handle at the reading end of the pipe. If C<ARGS> are given then C<fork>
is called and C<ARGS> are passed to exec.

=item writer ([ARGS])

The object is re-blessed into a sub-class of C<IO::Handle>, and becomes a
handle at the writing end of the pipe. If C<ARGS> are given then C<fork>
is called and C<ARGS> are passed to exec.

=item handles ()

This method is called during construction by C<IO::Pipe::new>
on the newly created C<IO::Pipe> object. It returns an array of two objects
blessed into C<IO::Pipe::End>, or a subclass thereof.

=back

=head1 SEE ALSO

L<IO::Handle>

=head1 AUTHOR

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

=head1 COPYRIGHT

=cut

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