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=head1 NAME |
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|
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Coro::Handle - non-blocking io with a blocking interface. |
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|
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=head1 SYNOPSIS |
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|
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use Coro::Handle; |
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|
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=head1 DESCRIPTION |
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|
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This module implements io-handles in a coroutine-compatible way, that is, |
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other coroutines can run while reads or writes block on the handle. It |
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does NOT inherit from IO::Handle but uses tied objects. |
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|
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=over 4 |
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|
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=cut |
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|
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package Coro::Handle; |
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|
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use Errno (); |
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use base 'Exporter'; |
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|
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$VERSION = 0.13; |
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|
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@EXPORT = qw(unblock); |
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|
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=item $fh = new_from_fh Coro::Handle $fhandle |
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|
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Create a new non-blocking io-handle using the given |
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perl-filehandle. Returns undef if no fhandle is given. |
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|
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=cut |
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|
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sub new_from_fh { |
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my $class = shift; |
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my $fh = shift or return; |
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my $self = do { local *Coro::Handle }; |
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|
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tie $self, Coro::Handle::FH, $fh; |
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|
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my $_fh = select bless \$self, $class; $| = 1; select $_fh; |
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} |
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|
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=item $fh = unblock $fh |
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|
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This is a convinience function that just calls C<new_from_fh> on the given |
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filehandle. Use it to replace a normal perl filehandle by a non-blocking |
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equivalent. |
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|
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=cut |
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|
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sub unblock($) { |
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new_from_fh Coro::Handle $_[0]; |
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} |
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|
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sub read { read $_[0], $_[1], $_[2], $_[3] } |
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sub sysread { sysread $_[0], $_[1], $_[2], $_[3] } |
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sub syswrite { syswrite $_[0], $_[1], $_[2], $_[3] } |
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|
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=item $fh->writable, $fh->readable |
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|
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Wait until the filehandle is readable or writable (and return true) or |
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until an error condition happens (and return false). |
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|
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=cut |
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|
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sub readable { tied(${$_[0]})->readable } |
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sub writable { tied(${$_[0]})->writable } |
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|
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=item $fh->readline([$terminator]) |
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|
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Like the builtin of the same name, but allows you to specify the input |
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record separator in a coroutine-safe manner (i.e. not usign a global |
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variable). |
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|
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=cut |
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|
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sub readline { tied(${+shift})->READLINE(@_) } |
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|
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=item $fh->autoflush([...]) |
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|
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Always returns true, arguments are being ignored (exists for compatibility |
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only). |
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|
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=cut |
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|
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sub autoflush { !0 } |
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|
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package Coro::Handle::FH; |
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|
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use Fcntl (); |
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use Errno (); |
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|
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use Coro::Event; |
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use Event::Watcher qw(R W E); |
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|
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use base 'Tie::Handle'; |
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|
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sub TIEHANDLE { |
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my ($class, $fh) = @_; |
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|
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fcntl $fh, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK |
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or die "fcntl(O_NONBLOCK): $!"; |
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|
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bless { |
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fh => $fh, |
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rb => "", |
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wb => "", |
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}, $_[0]; |
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|
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} |
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|
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sub OPEN { |
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my $self = shift; |
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$self->CLOSE; |
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my $r = @_ == 2 ? open $self->{fh}, $_[0], $_[1] |
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: open $self->{fh}, $_[0], $_[1], $_[2]; |
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if ($r) { |
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fcntl $self->{fh}, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK |
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or die "fcntl(O_NONBLOCK): $!"; |
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} |
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$r; |
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} |
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|
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sub CLOSE { |
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my $self = shift; |
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$self->{rb} = |
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$self->{wb} = ""; |
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(delete $self->{rw})->cancel if $self->{rw}; |
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(delete $self->{ww})->cancel if $self->{rw}; |
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close $self->{fh}; |
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} |
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|
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sub writable { |
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($_[0]->{ww} ||= Coro::Event->io(fd => $_[0]->{fh}, poll => W+E))->next->got & W; |
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} |
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|
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sub readable { |
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($_[0]->{rw} ||= Coro::Event->io(fd => $_[0]->{fh}, poll => R+E))->next->got & R; |
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} |
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|
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sub WRITE { |
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my $self = $_[0]; |
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my $len = defined $_[2] ? $_[2] : length $_[1]; |
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my $ofs = $_[3]; |
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my $res = 0; |
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|
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while() { |
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my $r = syswrite $self->{fh}, $_[1], $len, $ofs; |
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if (defined $r) { |
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$len -= $r; |
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$ofs += $r; |
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$res += $r; |
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last unless $len; |
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} elsif ($! != Errno::EAGAIN) { |
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last; |
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} |
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last unless $self->writable; |
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} |
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|
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return $res; |
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} |
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|
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sub READ { |
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my $self = $_[0]; |
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my $len = $_[2]; |
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my $ofs = $_[3]; |
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my $res = 0; |
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|
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while() { |
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my $r = sysread $self->{fh}, $_[1], $len, $ofs; |
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if (defined $r) { |
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$len -= $r; |
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$ofs += $r; |
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$res += $r; |
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last unless $len && $r; |
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} elsif ($! != Errno::EAGAIN) { |
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last; |
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} |
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last unless $self->readable; |
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} |
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|
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return $res; |
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} |
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|
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sub READLINE { |
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my $self = shift; |
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my $irs = @_ ? shift : $/; |
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|
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while() { |
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my $pos = index $self->{rb}, $irs; |
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if ($pos >= 0) { |
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$pos += length $/; |
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my $res = substr $self->{rb}, 0, $pos; |
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substr ($self->{rb}, 0, $pos) = ""; |
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return $res; |
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} |
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my $r = sysread $self->{fh}, $self->{rb}, 8192, length $self->{rb}; |
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if (defined $r) { |
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return undef unless $r; |
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} elsif ($! != Errno::EAGAIN || !$self->readable) { |
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return undef; |
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} |
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} |
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} |
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|
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1; |
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|
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=head1 BUGS |
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|
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- Perl's IO-Handle model is THE bug. |
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- READLINE cannot be mixed with other forms of input. |
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|
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=head1 AUTHOR |
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|
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Marc Lehmann <pcg@goof.com> |
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http://www.goof.com/pcg/marc/ |
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|
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=cut |
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|
