Re^3: why IPC::Open3 can't execute MS-DOS "dir" command?

Got an error like this:

Unknown error at C:\811150.pl line 18
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use Socket     qw( AF_INET SOCK_STREAM PF_UNSPEC );
use IPC::Open3 qw( open3 );

sub _pipe {
    socketpair($_[0], $_[1], AF_INET, SOCK_STREAM, PF_UNSPEC)
        or return undef;
    shutdown($_[0], 1);  # No more writing for reader
    shutdown($_[1], 0);  # No more reading for writer
    return 1;
}

sub _open3 {
    local (*TO_CHLD_R,     *TO_CHLD_W);
    local (*FR_CHLD_R,     *FR_CHLD_W);
    local (*FR_CHLD_ERR_R, *FR_CHLD_ERR_W);

    if ($^O =~ /Win32/) {
        _pipe(*TO_CHLD_R,     *TO_CHLD_W    ) or die $!;
        _pipe(*FR_CHLD_R,     *FR_CHLD_W    ) or die $!;
        _pipe(*FR_CHLD_ERR_R, *FR_CHLD_ERR_W) or die $!;
    } else {
        pipe(*TO_CHLD_R,     *TO_CHLD_W    ) or die $!;
        pipe(*FR_CHLD_R,     *FR_CHLD_W    ) or die $!;
        pipe(*FR_CHLD_ERR_R, *FR_CHLD_ERR_W) or die $!;
    }

    my $pid = open3('>&TO_CHLD_R', '<&FR_CHLD_W', '<&FR_CHLD_ERR_W', @
+_);

    return ( $pid, *TO_CHLD_W, *FR_CHLD_R, *FR_CHLD_ERR_R );
}


my $log="TestOpen3.log";
open FHO, ">$log";

select FHO;
my ($pid, $to_chld, $fr_chld, $fr_chld_err) = _open3("cmd /c dir * \/b
+\/s");
if((my $returnCode = $? >> 8) !=0){
    print "[ERROR] ($returnCode) : ";
    while(<$fr_chld_err>) 
    {
        print;
    }
    close $fr_chld_err;
    die $returnCode;
}
while(<$fr_chld>) 
{
    print "\t".$_;
}
close $fr_chld;
close FHO;
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Comment on Re^3: why IPC::Open3 can't execute MS-DOS "dir" command? Select or Download Code

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Re^4: why IPC::Open3 can't execute MS-DOS "dir" command? by ikegami (Patriarch) on Dec 07, 2009 at 23:56 UTC
Fixed: use strict; use warnings; use IO::Select qw( ); use IPC::Open3 qw( open3 ); use Socket qw( AF_UNIX SOCK_STREAM PF_UNSPEC ); sub _pipe { socketpair($_[0], $_[1], AF_UNIX, SOCK_STREAM, PF_UNSPEC) or return undef; shutdown($_[0], 1); # No more writing for reader shutdown($_[1], 0); # No more reading for writer return 1; } sub _open3 { local (TO_CHLD_R, TO_CHLD_W); local (FR_CHLD_R, FR_CHLD_W); local (FR_CHLD_ERR_R, FR_CHLD_ERR_W); if ($^O =~ /Win32/) { _pipe(TO_CHLD_R, TO_CHLD_W ) or die $^E; _pipe(FR_CHLD_R, FR_CHLD_W ) or die $^E; _pipe(FR_CHLD_ERR_R, FR_CHLD_ERR_W) or die $^E; } else { pipe(TO_CHLD_R, TO_CHLD_W ) or die $!; pipe(FR_CHLD_R, FR_CHLD_W ) or die $!; pipe(FR_CHLD_ERR_R, FR_CHLD_ERR_W) or die $!; } my $pid = open3('>&TO_CHLD_R', '<&FR_CHLD_W', '<&FR_CHLD_ERR_W', @ +_); return ( $pid, TO_CHLD_W, FR_CHLD_R, FR_CHLD_ERR_R ); } my ($pid, $to_chld, $fr_chld, $fr_chld_err) = _open3('cmd /c "dir /s/b"'); my %objs; my $in_sel = IO::Select->new(); my $out_sel = IO::Select->new(); for my $fh ($fr_chld, $fr_chld_err) { my $obj = { buf => '', }; $objs{ fileno($fh) } = $obj; $in_sel->add($fh); } close($to_chld); while ($in_sel->count() + $out_sel->count()) { my ($ins, $outs) = IO::Select::select($in_sel, $out_sel, undef); for my $fh (@$ins) { my $obj = $objs{ fileno($fh) }; our $buf; local buf = \( $obj->{buf} ); my $bytes_read = sysread($fh, $buf, 64*1024, length($buf)); if (!$bytes_read) { warn("Error reading from child: $!\n") if !defined($bytes_read); $in_sel->remove($fh); } } for my $fh (@$outs) { } } waitpid($pid, 0); print("STDOUT:\n$objs{ fileno( $fr_chld ) }{buf}"); print("\n"; print("STDERR:\n$objs{ fileno( $fr_chld_err ) }{buf}"); [download]	[reply] [d/l]
Re^4: why IPC::Open3 can't execute MS-DOS "dir" command? by ikegami (Patriarch) on Dec 07, 2009 at 18:12 UTC
the code was untested. I don't have time to look at this just now, but it's surely a problem with `socketpair`'s args. Start by changing `_pipe(TO_CHLD_R, TO_CHLD_W ) or die $!; _pipe(FR_CHLD_R, FR_CHLD_W ) or die $!; _pipe(FR_CHLD_ERR_R, FR_CHLD_ERR_W) or die $!;` [download] to `_pipe(TO_CHLD_R, TO_CHLD_W ) or die $^E; _pipe(FR_CHLD_R, FR_CHLD_W ) or die $^E; _pipe(FR_CHLD_ERR_R, FR_CHLD_ERR_W) or die $^E;` [download] to get a better error message.	[reply] [d/l] [select]