Perl/Tk IPC::Run and filevent fun on win32!

markzango has asked for the wisdom of the Perl Monks concerning the following question:

Hi Gang,

I'm trying to use IPC::Run along with filevent under win32 to capture the output from a console command. The code I'm using looks like:

use Tk 800.000;
use strict;
use Tk::LineNumberText;
use IPC::Run qw(start finish);

my $MW = MainWindow->new;

my $cmd_output = $MW->LineNumberText(-widget=>'ROText')->pack(-fill=>'
+both',-expand=>1);

my $harness = start(['cmd.exe','/C','echo hello'] , '<' ,\undef , ">pi
+pe", \*OUT,debug=>999) || die $!;

$MW->fileevent(\*OUT,'readable',[\&mycb,\*OUT,$harness]);

MainLoop;


sub mycb {
  $cmd_output->insert('end',"Callback called\n");
  my ($fh, $harness) = @_;
  my $n = sysread( $fh, my $buf, 8192 );

  if($n) {
     $cmd_output->insert('end',$buf);
     return;
  }

  $cmd_output->insert('end',"WARNING: $!") if not defined $n;
  $MW->fileevent( $fh, 'readable', '' );
  close $fh;
  $harness->finish;
}
[download]

Unfortunately, this doesn't seem to work for some reason. My understanding is that under Win32 select only works on sockets, and that IPC::Run uses sockets between processes to send information. Since fileevent uses select, I don't see why this isn't working. Debugging output:

IPC::Run 0000 0123-------- [#1(44744)]: debugging fd is 3
IPC::Run 0000 0123-------- [#1(44744)]: ** starting
IPC::Run 0000 0123-------- [#1(44744)]: 'cmd.exe' added to cache: 'C:\
+WINDOWS\system32\cmd.exe'
IPC::Run 0000 0123-------- [#1(44744)]: kid 1 to read 0 from SCALAR
IPC::Run 0000 01234------- [#1(44744)]: win32 port = 2048
IPC::Run 0000 012345------ [#1(44744)]: accept()ing on port 2048
IPC::Run 0000 0123456----- [#1(44744)]: win32 _socket = ( 6, 5 ) on po
+rt 2048
IPC::Run 0000 0123-56----- [#1(44744)]: PUMP_SOCKET_HANDLE = 5
IPC::Run 0000 01234567---- [#1(44744)]: CHILD_HANDLE = 4
IPC::Run 0000 01234567---- [#1(44744)]: PUMP_PIPE_HANDLE = 7
IPC::Run 0000 01234567---- [#1(44744)]: disabling inheritance of 6
IPC::Run 0000 01234567---- [#1(44744)]: disabling inheritance of 5
IPC::Run 0000 01234567---- [#1(44744)]: disabling inheritance of 7
IPC::Run 0000 01234567---- [#1(44744)]: disabling inheritance of 4
IPC::Run 0000 01234567---- [#1(44744)]: pumper stdin = 5
IPC::Run 0000 01234567---- [#1(44744)]: pumper stdout = 7
IPC::Run 0000 01234567---- [#1(44744)]: enabling inheritance of 5
IPC::Run 0000 01234567---- [#1(44744)]: enabling inheritance of 7
IPC::Run 0000 01234567---- [#1(44744)]: enabling inheritance of 3
IPC::Run 0000 01234567---- [#1(44744)]: pump cmd line: "C:\Perl\bin\pe
+rl.exe" "-IC:\Program Files\ActiveState Perl Dev Kit 6.0\lib\" "-IC:/
+Perl/lib" "
-IC:/Perl/site/lib" "-I." -MIPC::Run::Win32Pump -e 1 1852 1876 15 0 44
+744 1123101917 999 "4<pump<6"
IPC::Run 0000 01234-6----- [#1(44744)]: _spawn_pumper pid = 43144
IPC::Run 0000 01234-6----- [#1(44744)]: win32_fake_pipe = ( 6, 4 )
IPC::Run 0000 01234-6----- [#1(44744)]: kid 1 to write 1 to a pipe IPC
+::Run opens and returns
IPC::Run 0000 0123456----- [#1(44744)]: win32 port = 2049
IPC::Run 0000 01234567---- [#1(44744)]: accept()ing on port 2049
IPC::Run 0000 012345678--- [#1(44744)]: win32 _socket = ( 8, 7 ) on po
+rt 2049
IPC::Run 0000 01234-678--- [#1(44744)]: PUMP_SOCKET_HANDLE = 7
IPC::Run 0000 0123456789-- [#1(44744)]: CHILD_HANDLE = 9
IPC::Run 0000 0123456789-- [#1(44744)]: PUMP_PIPE_HANDLE = 5
IPC::Run 0000 0123456789-- [#1(44744)]: disabling inheritance of 8
IPC::Run 0000 0123456789-- [#1(44744)]: disabling inheritance of 7
IPC::Run 0000 0123456789-- [#1(44744)]: disabling inheritance of 5
IPC::Run 0000 0123456789-- [#1(44744)]: disabling inheritance of 9
IPC::Run 0000 0123456789-- [#1(44744)]: pumper stdin = 5
IPC::Run 0000 0123456789-- [#1(44744)]: pumper stdout = 7
IPC::Run 0000 0123456789-- [#1(44744)]: enabling inheritance of 5
IPC::Run 0000 0123456789-- [#1(44744)]: enabling inheritance of 7
IPC::Run 0000 0123456789-- [#1(44744)]: enabling inheritance of 3
IPC::Run 0000 0123456789-- [#1(44744)]: pump cmd line: "C:\Perl\bin\pe
+rl.exe" "-IC:\Program Files\ActiveState Perl Dev Kit 6.0\lib\" "-IC:/
+Perl/lib" "
-IC:/Perl/site/lib" "-I." -MIPC::Run::Win32Pump -e 1 1808 1876 15 0 44
+744 1123101917 999 "9>pump>8"
IPC::Run 0000 01234-6-89-- [#1(44744)]: _spawn_pumper pid = 43888
IPC::Run 0000 01234-6-89-- [#1(44744)]: win32_fake_pipe = ( 8, 9 )
IPC::Run 0001 01234-6-89-- [#1(44744)]: caller will read from 8
IPC::Run 0001 01234-6-89-- [#1(44744)]: kid 1 to write 2 to '1' (write
+ only, create, truncate)
IPC::Run 0001 01234-6-89-- [#1(44744)]: O_RDONLY=0x00 O_WRONLY=0x01 O_
+RDWR=0x02 O_TRUNC=0x200 O_CREAT=0x100 O_APPEND=0x08
IPC::Run 0001 0123456-89-- [#1(44744)]: open( 1, 0x301 ) = 5
IPC::Run 0001 0123456-89-- [#1(44744)]: kid 1[]'s 0 is my 6
IPC::Run 0001 0123456-89-- [#1(44744)]: child: `cmd.exe '/C' 'echo hel
+lo'`
IPC::Run 0001 0123456-89-- [#1(44744)]: spawning 'C:\WINDOWS\system32\
+cmd.exe' '/C' 'echo hello'
IPC::Run 0001 0123456-89-- [#1(44744)]: disabling inheritance of 3
IPC::Run 0001 0123456-89-- [#1(44744)]: disabling inheritance of 6
IPC::Run 0001 0123456789-- [#1(44744)]: dup( 0 ) = 7
IPC::Run 0001 0123456789-- [#1(44744)]: disabling inheritance of 7
IPC::Run 0001 0123456789-- [#1(44744)]: disabling inheritance of 7
IPC::Run 0001 0123456789-- [#1(44744)]: moving 4 to kid's 0
IPC::Run 0001 0123456789-- [#1(44744)]: dup2( 4, 0 ) = 0
IPC::Run 0001 0123456789-- [#1(44744)]: disabling inheritance of 4
IPC::Run 0001 01234567890- [#1(44744)]: dup( 1 ) = 10
IPC::Run 0001 01234567890- [#1(44744)]: disabling inheritance of 10
IPC::Run 0001 01234567890- [#1(44744)]: disabling inheritance of 10
IPC::Run 0001 01234567890- [#1(44744)]: moving 9 to kid's 1
IPC::Run 0001 01234567890- [#1(44744)]: dup2( 9, 1 ) = 0
IPC::Run 0001 01234567890- [#1(44744)]: disabling inheritance of 9
IPC::Run 0001 012345678901 [#1(44744)]: dup( 2 ) = 11
IPC::Run 0001 012345678901 [#1(44744)]: disabling inheritance of 11
IPC::Run 0001 012345678901 [#1(44744)]: disabling inheritance of 11
IPC::Run 0001 012345678901 [#1(44744)]: moving 5 to kid's 2
IPC::Run 0001 012345678901 [#1(44744)]: dup2( 5, 2 ) = 0
IPC::Run 0001 012345678901 [#1(44744)]: disabling inheritance of 5
IPC::Run 0001 012345678901 [#1(44744)]: cmd line: C:\WINDOWS\system32\
+cmd.exe /C "echo hello"
IPC::Run 0001 012345678901 [#1(44744)]: dup2( 10, 1 ) = 0
IPC::Run 0001 0123456789-1 [#1(44744)]: close( 10 ) = 0
IPC::Run 0001 0123456789-1 [#1(44744)]: dup2( 7, 0 ) = 0
IPC::Run 0001 0123456-89-1 [#1(44744)]: close( 7 ) = 0
IPC::Run 0001 0123456-89-1 [#1(44744)]: dup2( 11, 2 ) = 0
IPC::Run 0001 0123456-89-- [#1(44744)]: close( 11 ) = 0
IPC::Run 0001 0123456-89-- [#1(44744)]: spawn() = 43092
IPC::Run 0001 0123-56-89-- [#1(44744)]: close( 4 ) = 0
IPC::Run 0001 0123-56-8--- [#1(44744)]: close( 9 ) = 0
IPC::Run 0001 0123--6-8--- [#1(44744)]: close( 5 ) = 0
[download]

Any ideas?

Mark

holli added readmore tags

Comment on Perl/Tk IPC::Run and filevent fun on win32! Select or Download Code

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Re: Perl/Tk IPC::Run and filevent fun on win32! by zentara (Cardinal) on Aug 04, 2005 at 11:45 UTC
Ideas? Yes. Apparently fileevent dosn't work well on all win32 platforms. See Perl/Tk App and Interprocess Communication for a discussion. I'm not really a human, but I play one on earth. flash japh	[reply]