I would suggest that you make sure that autoflush is turned on for both
STDOUT and STDERR before you run the command.
select((select(STDOUT), $|=1)[0]);
select((select(STDERR), $|=1)[0]);
I'm not sure if this will help for a command run via backticks or not, but
I've corrected similar "output order" problems with this trick.
wantor
> -----Original Message-----
> From: Chad Wallace [mailto:[EMAIL PROTECTED]]
> Sent: Thursday, August 10, 2000 1:53 PM
> To: '[EMAIL PROTECTED]'
> Cc: [EMAIL PROTECTED]
> Subject: RE: Capturing output from a child's STDOUT and STDERR
> simultaneou sly
>
>
> That doesn't give them in the proper order. I get all the
> STDOUT lines
> first, then all the STDERR lines after them. I might just
> have to settle
> with that. It's so uncool, though. :-(
>
> BTW, I know the output can be received in the proper order
> because when I
> run a Perl script redirected into EditPlus, and it has warnings, the
> warnings (which are on STDERR) show up intermixed with the
> regular output,
> not just at the end. ... I just need to find how it can be
> done in Perl.
>
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]
> Sent: August 10, 2000 11:26
> To: [EMAIL PROTECTED]
> Cc: [EMAIL PROTECTED]
> Subject: RE: Capturing output from a child's STDOUT and STDERR
> simultaneou sly
>
>
> Chad,
>
> Depending on exactly what commands you are running, and how
> you are running
> them, you might be able to redirect the stderr to the stdout using the
> command prompt command '2>&1'. I've use this successfully to
> capture stderr
> output from dos commands executed via the backquotes. For example,
>
> $listing = `dir`;
>
> would capture the directory listing (if any) in the $listing
> variable, but
> any errors would still go to the screen. However,
>
> $listing = `dir 2>&1`;
>
> would capture both the directory listing and any errors in
> the $listing
> variable.
>
>
> HTH,
>
> wantor
>
> > -----Original Message-----
> > From: Chad Wallace [mailto:[EMAIL PROTECTED]]
> > Sent: Thursday, August 10, 2000 12:46 PM
> > To: '$Bill Luebkert'
> > Cc: Perl-Win32-Users Mailing List (E-mail)
> > Subject: RE: Capturing output from a child's STDOUT and STDERR
> > simultaneou sly
> >
> >
> > Well, I just tried duping STDERR to STDOUT, and it doesn't
> work. The
> > child's STDERR output just goes to the screen, and the parent
> > only receives
> > the child's STDOUT output. I'm guessing that the child
> > doesn't inherit the
> > parent's duped STDERR. It just gets its own.
> >
> > -----Original Message-----
> > From: $Bill Luebkert [mailto:[EMAIL PROTECTED]]
> > Sent: August 9, 2000 16:05
> > To: Chad Wallace
> > Cc: Perl-Win32-Users Mailing List (E-mail)
> > Subject: Re: Capturing output from a child's STDOUT and STDERR
> > simultaneously
> >
> >
> > Chad Wallace wrote:
> > >
> > > Hi, guys.
> > >
> > > I'll bet you're scared already, just from reading the
> > subject line. :-)
> > >
> > > I want to capture all output that comes from a child--both
> > to STDOUT and
> > to
> > > STDERR--into a while loop so I can process it. The child
> > might be any DOS
> > > command. I would like the lines to come to me in order.
> > ie: If I print
> > > line A to STDOUT then line B to STDERR then line C to
> > STDOUT again, I want
> > > to recieve them as A then B then C, not A then C then B as
> > IPC::Open3
> > gives
> > > them by default.
> > >
> > > The Open3 documentation talked about using select() and
> > sysread() to read
> > > from the open3 handles, but I can't figure those functions
> > out, and the
> > Perl
> > > documentation on the select function is pretty weird (vec()
> > and fileno(),
> > > etc), and the select(2) manpage isn't much better.
> > Needless to say, I
> > > couldn't get it to work this way. select kept giving 'Bad file
> > descriptor'.
> > >
> > > Is there a better way to do this? Or is there some place I
> > could learn
> > how
> > > select() and sysread() are supposed to be used with IPC::Open3?
> > >
> > > Thanks...
> > > Chad.
> > >
> > > FWIW, here is the code that I have come up with so far,
> > from what I could
> > > glean off of the various perldoc's:
> > > [stdouterrtest.pl -- The tester child]
> > > print STDOUT "out: one\n";
> > > print STDERR "err: one\n";
> > > print STDOUT "out: two\n";
> > > print STDERR "err: two\n";
> > > print STDERR "err: parm1 = $ARGV[0]\n";
> > > print STDOUT "out: parm2 = $ARGV[1]\n";
> > > __END__
> > >
> > > [open3Test.pl -- The main program]
> > > #!perl -w
> > > use IPC::Open3;
> > > require FileHandle;
> > > use strict;
> > >
> > > my $command = q/perl c:\buildscripts\stdouterrtest.pl
> parm1 parm2/;
> > >
> > > my $in = FileHandle->new;
> > > my $out = FileHandle->new;
> > > my $err = FileHandle->new;
> > >
> > > open3($in, $out, $err, $command);
> > >
> > > my ($outbits, $errbits) = ('','');
> > > vec($outbits, fileno($out), 1) = 1;
> > > vec($errbits, fileno($err), 1) = 1;
> > >
> > > my $go = 1;
> > > while ($go or $!) # Go until sysread returns 0.
> > > {
> > > my $buf;
> > > my ($outfound, $errfound);
> > > $outfound = select($outbits, undef, undef, undef);
> > > print "OUT: $outfound, $!\n";
> > > if ($outfound == 1)
> > > {
> > > $go = sysread($out, $buf, 1000);
> > > print $buf;
> > > }
> > >
> > > $errfound = select($errbits, undef, undef, undef);
> > > print "ERR: $errfound, $!\n";
> > > if ($errfound == 1 and $go)
> > > {
> > > $go = sysread($err, $buf, 1000);
> > > print $buf;
> > > }
> > > }
> > >
> > > $out->close;
> > > $err->close;
> > > $in->close;
> > >
> > > print STDOUT "Done!\n";
> > > __END__
> >
> > Have you tried just duping STDERR to STDOUT and then running
> > backticks
> > to the other process?
> >
> > open STDERR, ">&STDOUT" or die "Can't dup stderr to stdout: $!";
> > @results = `run some command here`;
> > foreach (@results) {
> > ...
> > }
> >
> > --
> > ,-/- __ _ _ $Bill Luebkert ICQ=14439852
> > (_/ / ) // // DBE Collectibles
> http://www.wgn.net/~dbe/
> > / ) /--< o // //
> Mailto:[EMAIL PROTECTED]
> > http://dbecoll.webjump.com/
> > -/-' /___/_<_</_</_
> > http://www.freeyellow.com/members/dbecoll/
> > _______________________________________________
> > Perl-Win32-Users mailing list
> > [EMAIL PROTECTED]
> > http://listserv.ActiveState.com/mailman/listinfo/perl-win32-users
> >
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