Current File : //usr/share/perl5/vendor_perl/IPC/Run/IO.pm
package IPC::Run::IO;
=head1 NAME
IPC::Run::IO -- I/O channels for IPC::Run.
=head1 SYNOPSIS
B<NOT IMPLEMENTED YET ON Win32! Win32 does not allow select() on
normal file descriptors; IPC::RUN::IO needs to use IPC::Run::Win32Helper
to do this.>
use IPC::Run qw( io );
## The sense of '>' and '<' is opposite of perl's open(),
## but agrees with IPC::Run.
$io = io( "filename", '>', \$recv );
$io = io( "filename", 'r', \$recv );
## Append to $recv:
$io = io( "filename", '>>', \$recv );
$io = io( "filename", 'ra', \$recv );
$io = io( "filename", '<', \$send );
$io = io( "filename", 'w', \$send );
$io = io( "filename", '<<', \$send );
$io = io( "filename", 'wa', \$send );
## Handles / IO objects that the caller opens:
$io = io( \*HANDLE, '<', \$send );
$f = IO::Handle->new( ... ); # Any subclass of IO::Handle
$io = io( $f, '<', \$send );
require IPC::Run::IO;
$io = IPC::Run::IO->new( ... );
## Then run(), harness(), or start():
run $io, ...;
## You can, of course, use io() or IPC::Run::IO->new() as an
## argument to run(), harness, or start():
run io( ... );
=head1 DESCRIPTION
This class and module allows filehandles and filenames to be harnessed for
I/O when used IPC::Run, independent of anything else IPC::Run is doing
(except that errors & exceptions can affect all things that IPC::Run is
doing).
=head1 SUBCLASSING
INCOMPATIBLE CHANGE: due to the awkwardness introduced in ripping pseudohashes
out of Perl, this class I<no longer> uses the fields pragma.
=cut
## This class is also used internally by IPC::Run in a very intimate way,
## since this is a partial factoring of code from IPC::Run plus some code
## needed to do standalone channels. This factoring process will continue
## at some point. Don't know how far how fast.
use strict;
use Carp;
use Fcntl;
use Symbol;
use IPC::Run::Debug;
use IPC::Run qw( Win32_MODE );
use vars qw{$VERSION};
BEGIN {
$VERSION = '0.99';
if (Win32_MODE) {
eval "use IPC::Run::Win32Helper; require IPC::Run::Win32IO; 1"
or ( $@ && die )
or die "$!";
}
}
sub _empty($);
*_empty = \&IPC::Run::_empty;
=head1 SUBROUTINES
=over 4
=item new
I think it takes >> or << along with some other data.
TODO: Needs more thorough documentation. Patches welcome.
=cut
sub new {
my $class = shift;
$class = ref $class || $class;
my ( $external, $type, $internal ) = ( shift, shift, pop );
croak "$class: '$_' is not a valid I/O operator"
unless $type =~ /^(?:<<?|>>?)$/;
my IPC::Run::IO $self = $class->_new_internal( $type, undef, undef, $internal, undef, @_ );
if ( !ref $external ) {
$self->{FILENAME} = $external;
}
elsif ( ref $external eq 'GLOB' || UNIVERSAL::isa( $external, 'IO::Handle' ) ) {
$self->{HANDLE} = $external;
$self->{DONT_CLOSE} = 1;
}
else {
croak "$class: cannot accept " . ref($external) . " to do I/O with";
}
return $self;
}
## IPC::Run uses this ctor, since it preparses things and needs more
## smarts.
sub _new_internal {
my $class = shift;
$class = ref $class || $class;
$class = "IPC::Run::Win32IO"
if Win32_MODE && $class eq "IPC::Run::IO";
my IPC::Run::IO $self;
$self = bless {}, $class;
my ( $type, $kfd, $pty_id, $internal, $binmode, @filters ) = @_;
# Older perls (<=5.00503, at least) don't do list assign to
# psuedo-hashes well.
$self->{TYPE} = $type;
$self->{KFD} = $kfd;
$self->{PTY_ID} = $pty_id;
$self->binmode($binmode);
$self->{FILTERS} = [@filters];
## Add an adapter to the end of the filter chain (which is usually just the
## read/writer sub pushed by IPC::Run) to the DEST or SOURCE, if need be.
if ( $self->op =~ />/ ) {
croak "'$_' missing a destination" if _empty $internal;
$self->{DEST} = $internal;
if ( UNIVERSAL::isa( $self->{DEST}, 'CODE' ) ) {
## Put a filter on the end of the filter chain to pass the
## output on to the CODE ref. For SCALAR refs, the last
## filter in the chain writes directly to the scalar itself. See
## _init_filters(). For CODE refs, however, we need to adapt from
## the SCALAR to calling the CODE.
unshift(
@{ $self->{FILTERS} },
sub {
my ($in_ref) = @_;
return IPC::Run::input_avail() && do {
$self->{DEST}->($$in_ref);
$$in_ref = '';
1;
}
}
);
}
}
else {
croak "'$_' missing a source" if _empty $internal;
$self->{SOURCE} = $internal;
if ( UNIVERSAL::isa( $internal, 'CODE' ) ) {
push(
@{ $self->{FILTERS} },
sub {
my ( $in_ref, $out_ref ) = @_;
return 0 if length $$out_ref;
return undef
if $self->{SOURCE_EMPTY};
my $in = $internal->();
unless ( defined $in ) {
$self->{SOURCE_EMPTY} = 1;
return undef;
}
return 0 unless length $in;
$$out_ref = $in;
return 1;
}
);
}
elsif ( UNIVERSAL::isa( $internal, 'SCALAR' ) ) {
push(
@{ $self->{FILTERS} },
sub {
my ( $in_ref, $out_ref ) = @_;
return 0 if length $$out_ref;
## pump() clears auto_close_ins, finish() sets it.
return $self->{HARNESS}->{auto_close_ins} ? undef : 0
if IPC::Run::_empty ${ $self->{SOURCE} }
|| $self->{SOURCE_EMPTY};
$$out_ref = $$internal;
eval { $$internal = '' }
if $self->{HARNESS}->{clear_ins};
$self->{SOURCE_EMPTY} = $self->{HARNESS}->{auto_close_ins};
return 1;
}
);
}
}
return $self;
}
=item filename
Gets/sets the filename. Returns the value after the name change, if
any.
=cut
sub filename {
my IPC::Run::IO $self = shift;
$self->{FILENAME} = shift if @_;
return $self->{FILENAME};
}
=item init
Does initialization required before this can be run. This includes open()ing
the file, if necessary, and clearing the destination scalar if necessary.
=cut
sub init {
my IPC::Run::IO $self = shift;
$self->{SOURCE_EMPTY} = 0;
${ $self->{DEST} } = ''
if $self->mode =~ /r/ && ref $self->{DEST} eq 'SCALAR';
$self->open if defined $self->filename;
$self->{FD} = $self->fileno;
if ( !$self->{FILTERS} ) {
$self->{FBUFS} = undef;
}
else {
@{ $self->{FBUFS} } = map {
my $s = "";
\$s;
} ( @{ $self->{FILTERS} }, '' );
$self->{FBUFS}->[0] = $self->{DEST}
if $self->{DEST} && ref $self->{DEST} eq 'SCALAR';
push @{ $self->{FBUFS} }, $self->{SOURCE};
}
return undef;
}
=item open
If a filename was passed in, opens it. Determines if the handle is open
via fileno(). Throws an exception on error.
=cut
my %open_flags = (
'>' => O_RDONLY,
'>>' => O_RDONLY,
'<' => O_WRONLY | O_CREAT | O_TRUNC,
'<<' => O_WRONLY | O_CREAT | O_APPEND,
);
sub open {
my IPC::Run::IO $self = shift;
croak "IPC::Run::IO: Can't open() a file with no name"
unless defined $self->{FILENAME};
$self->{HANDLE} = gensym unless $self->{HANDLE};
_debug "opening '", $self->filename, "' mode '", $self->mode, "'"
if _debugging_data;
sysopen(
$self->{HANDLE},
$self->filename,
$open_flags{ $self->op },
) or croak "IPC::Run::IO: $! opening '$self->{FILENAME}', mode '" . $self->mode . "'";
return undef;
}
=item open_pipe
If this is a redirection IO object, this opens the pipe in a platform
independent manner.
=cut
sub _do_open {
my $self = shift;
my ( $child_debug_fd, $parent_handle ) = @_;
if ( $self->dir eq "<" ) {
( $self->{TFD}, $self->{FD} ) = IPC::Run::_pipe_nb;
if ($parent_handle) {
CORE::open $parent_handle, ">&=$self->{FD}"
or croak "$! duping write end of pipe for caller";
}
}
else {
( $self->{FD}, $self->{TFD} ) = IPC::Run::_pipe;
if ($parent_handle) {
CORE::open $parent_handle, "<&=$self->{FD}"
or croak "$! duping read end of pipe for caller";
}
}
}
sub open_pipe {
my IPC::Run::IO $self = shift;
## Hmmm, Maybe allow named pipes one day. But until then...
croak "IPC::Run::IO: Can't pipe() when a file name has been set"
if defined $self->{FILENAME};
$self->_do_open(@_);
## return ( child_fd, parent_fd )
return $self->dir eq "<"
? ( $self->{TFD}, $self->{FD} )
: ( $self->{FD}, $self->{TFD} );
}
sub _cleanup { ## Called from Run.pm's _cleanup
my $self = shift;
undef $self->{FAKE_PIPE};
}
=item close
Closes the handle. Throws an exception on failure.
=cut
sub close {
my IPC::Run::IO $self = shift;
if ( defined $self->{HANDLE} ) {
close $self->{HANDLE}
or croak(
"IPC::Run::IO: $! closing "
. (
defined $self->{FILENAME}
? "'$self->{FILENAME}'"
: "handle"
)
);
}
else {
IPC::Run::_close( $self->{FD} );
}
$self->{FD} = undef;
return undef;
}
=item fileno
Returns the fileno of the handle. Throws an exception on failure.
=cut
sub fileno {
my IPC::Run::IO $self = shift;
my $fd = fileno $self->{HANDLE};
croak(
"IPC::Run::IO: $! "
. (
defined $self->{FILENAME}
? "'$self->{FILENAME}'"
: "handle"
)
) unless defined $fd;
return $fd;
}
=item mode
Returns the operator in terms of 'r', 'w', and 'a'. There is a state
'ra', unlike Perl's open(), which indicates that data read from the
handle or file will be appended to the output if the output is a scalar.
This is only meaningful if the output is a scalar, it has no effect if
the output is a subroutine.
The redirection operators can be a little confusing, so here's a reference
table:
> r Read from handle in to process
< w Write from process out to handle
>> ra Read from handle in to process, appending it to existing
data if the destination is a scalar.
<< wa Write from process out to handle, appending to existing
data if IPC::Run::IO opened a named file.
=cut
sub mode {
my IPC::Run::IO $self = shift;
croak "IPC::Run::IO: unexpected arguments for mode(): @_" if @_;
## TODO: Optimize this
return ( $self->{TYPE} =~ /</ ? 'w' : 'r' ) . ( $self->{TYPE} =~ /<<|>>/ ? 'a' : '' );
}
=item op
Returns the operation: '<', '>', '<<', '>>'. See L</mode> if you want
to spell these 'r', 'w', etc.
=cut
sub op {
my IPC::Run::IO $self = shift;
croak "IPC::Run::IO: unexpected arguments for op(): @_" if @_;
return $self->{TYPE};
}
=item binmode
Sets/gets whether this pipe is in binmode or not. No effect off of Win32
OSs, of course, and on Win32, no effect after the harness is start()ed.
=cut
sub binmode {
my IPC::Run::IO $self = shift;
$self->{BINMODE} = shift if @_;
return $self->{BINMODE};
}
=item dir
Returns the first character of $self->op. This is either "<" or ">".
=cut
sub dir {
my IPC::Run::IO $self = shift;
croak "IPC::Run::IO: unexpected arguments for dir(): @_" if @_;
return substr $self->{TYPE}, 0, 1;
}
##
## Filter Scaffolding
##
#my $filter_op ; ## The op running a filter chain right now
#my $filter_num; ## Which filter is being run right now.
use vars (
'$filter_op', ## The op running a filter chain right now
'$filter_num' ## Which filter is being run right now.
);
sub _init_filters {
my IPC::Run::IO $self = shift;
confess "\$self not an IPC::Run::IO" unless UNIVERSAL::isa( $self, "IPC::Run::IO" );
$self->{FBUFS} = [];
$self->{FBUFS}->[0] = $self->{DEST}
if $self->{DEST} && ref $self->{DEST} eq 'SCALAR';
return unless $self->{FILTERS} && @{ $self->{FILTERS} };
push @{ $self->{FBUFS} }, map {
my $s = "";
\$s;
} ( @{ $self->{FILTERS} }, '' );
push @{ $self->{FBUFS} }, $self->{SOURCE};
}
=item poll
TODO: Needs confirmation that this is correct. Was previously undocumented.
I believe this is polling the IO for new input and then returns undef if there will never be any more input, 0 if there is none now, but there might be in the future, and TRUE if more input was gotten.
=cut
sub poll {
my IPC::Run::IO $self = shift;
my ($harness) = @_;
if ( defined $self->{FD} ) {
my $d = $self->dir;
if ( $d eq "<" ) {
if ( vec $harness->{WOUT}, $self->{FD}, 1 ) {
_debug_desc_fd( "filtering data to", $self )
if _debugging_details;
return $self->_do_filters($harness);
}
}
elsif ( $d eq ">" ) {
if ( vec $harness->{ROUT}, $self->{FD}, 1 ) {
_debug_desc_fd( "filtering data from", $self )
if _debugging_details;
return $self->_do_filters($harness);
}
}
}
return 0;
}
sub _do_filters {
my IPC::Run::IO $self = shift;
( $self->{HARNESS} ) = @_;
my ( $saved_op, $saved_num ) = ( $IPC::Run::filter_op, $IPC::Run::filter_num );
$IPC::Run::filter_op = $self;
$IPC::Run::filter_num = -1;
my $redos = 0;
my $r;
{
$@ = '';
$r = eval { IPC::Run::get_more_input(); };
# Detect Resource temporarily unavailable and re-try 200 times (2 seconds), assuming select behaves (which it doesn't always? need ref)
if ( ( $@ || '' ) =~ $IPC::Run::_EAGAIN && $redos++ < 200 ) {
select( undef, undef, undef, 0.01 );
redo;
}
}
( $IPC::Run::filter_op, $IPC::Run::filter_num ) = ( $saved_op, $saved_num );
$self->{HARNESS} = undef;
die "ack ", $@ if $@;
return $r;
}
=back
=head1 AUTHOR
Barrie Slaymaker <barries@slaysys.com>
=head1 TODO
Implement bidirectionality.
=cut
1;
Mini Shell